Groundwater remarkably affects the strength and deformation of rock mass. It is underground fissure water that lowers the strength of rockmass and weakens stability of surrounding rock. In order to reflect the influence of groundwater on the stability of Dagangshan large-scale underground power house, according to coupling action mechanism of seepage and rock mass structure, this paper utilize the program of FLAC3D is appliced to analyze its stability under the action of groundwater. Computational results indicate that although the coupling action is unfavorable to the stability of surrounding rock, the reinforced underground cavern groups have been stable.

Geomaterials, that are soil, frozen soil, rock and concrete present obviously the phenomena of creep and stress relaxation. By means of the creep tests, their creep compliances can be determined easily. Their relaxation moduli can’t be determined, because it is difficult to do relaxation tests of stress. So till now, there is no a suitable method to determine their relaxation moduli. In this paper, the relaxation moduli of geomaterials are calculated analytically, according to their creep compliances. And three andlytical examples are given.

Rock is a kind of very complicated medium formed by many geo-actions, creep is a typical mechanical feature for it. To find some new simulating approaches for rock creep is an important task in rock mechanics. Based on 8-neibours Moore cell, an arithmetic of rock creep and failure evolving process is constructed through the broad sense energy dissipation and transmitted from one cell to the others, an effective simulating rock creep model of MH-PCA is built; and corresponding simulating software is compiled. By using the creep MH-PCA software, the process from stable creep, critical creep to the accelerated creep of rock has been simulated effectively. It is valuable for researching the rock creep action ulteriorly.

There are large numbers of holes and cracks existed in the natural rock mass, these defects not only change the mechanical character of rock mass, but also affect the seepage characteristics of rock mass. Based on analyzing the present production of seepage characteristics of fractured rock mass, the mechanical character of a rock mass with a single joint and the mechanical function that the seepage impacted on rock mass with a single joint are discussed; and the relation between the permeability coefficient and 3D stresses in the rock mass with a single joint is studied. The influence of the crack coarseness degree on the seepage and the different influences of the different acting directions of stresses on the seepage characteristics of rock mass are considered; the seepage characteristics of rock masses with a single joint under 3D stresses is analyzed; and the relation between stresses acted on the crack and the permeability coefficient is proposed. It is shown that the vertical stress acted on the face of the crack takes a dominant effect on the permeability of rock mass; and the permeability coefficient decreases rapidly with the increasing of the vertical stress acted on the face of the crack. By analyzing and comparing the result of an experiment of seepage law made by Zhao Yang-sheng, the correctness of the expression of permeability coefficient of fractured rock mass with a single joint proposed in this paper, is proved.

Intermittent joints are important factors affecting stability of surrounding rockmass. In order to reflect their influence, based on large-sized underground chambers of Ertan Hydropower Project, an interface model is established to simulate mechanical effect of intermittent joints. Taking into account intermittent joint action or not, we have carried out numerical computation analysis for the main opening under various geostress and got some changing laws of displacement field and plastic zone around opening, which provide some useful reference for stability analysis of large sized underground engineering.

The variations of five mechanical conditions such as the surface settlements, the displacement at vault of tunnels, the distribution of plastic zone of surrounding loess, the moment distribution of lining element and the total strain energy of surrounding loess are studied under three kinds of lining procedure with two different tunnel constructions, which is sequential excavation with a central heading and with a lateral heading. The results show that the sequential excavation with a lateral heading, which can decrease the amount of displacement at the vault of tunnels and of the maximal surface settlement and of the plastic zone of surrounding loess, is more preferable than that with a central heading. The tunnel lining in delayed construction compared with that in immediate construction is more favorable to enhance the stability of loess tunnel. It is shown that the analytical results are helpful for the design and construction of loess tunnels.

Based on research results of composite material and continuum damage mechanics theory, a three-dimensional anisotropic damage model was presented. To describe the damage evolution of rock material during loading/unloading, the derivate eigenmodes in the proposed model are assumed to be related with the uniaxial behavior of the rock material. Each eigenmode has a corresponding damage variable due to the fact that damage is a function of the magnitude of the eigenstrain. Within an eigenmodes, different damage variables can be used for tension and compression. Hence, these damage variables in six eigenmodes can form a 4th rank symmetric damage tensor which stipulates evaluation of effective elastic modulus of the rock material with microcracks and an adequate description of the evolution of damage. In this model, the tensor decomposition technique is employed. It means that the stress and strain tensors are decomposed into six eigentensors, which correspond to six eigenvalues accordingly. The stress-strain curves for different directions, which can be obtained from the experiment, are assumed to be different in each normal eigenmodes. This model was also developed into finite element code in explicit format; and the code was integrated into the well-known computational environment ABAQUS using the ABAQUS/Explicit Solver. Numerical simulation of an uniaxial compressive test for a rock sample is used to examine the performance of the proposed model. The results of the numerical simulation show that it is possible to reproduce most of the observable characteristics of anisotropic behavior and damaged zone in rock materials.

The heavy metal cations transport in clay-solidified grouting curtain is studied for the pollution of groundwater in Maiyuan Domestic Waste Landfill in Nanchang city. A couple mathematical model for groundwater flow and heavy metal cations migration was developed based on analyzing the characteristics of migration and transformation of heavy metal leaching from the landfill to groundwater through the clay-solidified grouting curtain. The pollution of groundwater of Maiyuan problem is used to provide a quantitative verification and validation of the model. The result indicates that the retention ratio of clay-solidified grouting curtain to heavy metal cations is higher than 94.5 %; heavy metal concentration values increase with longer time and decrease with distance from the pollution source. Combined with the measured data in landfill site, clay-solidified grouting curtain was proved to serve as a sufficiently effective vertical barrier against heavy metal cations transport in municipal solid waste landfills.

The exact analytical solution to the constitutive relation of Jaumann rate-type has not yet been found in the magnitudes of stress and strain. The variation of Kirchhoff stress with Green strain for one-dimensional large strain problems was studied using finite-element method. Based on the principle of virtual work, the large strain FEM was formulated in terms of total Lagrangian description. A new hyperbolic model for simulating the large strain constitutive relations was put forward along with the rearrangement method of secant modulus. The results of numerical simulation show that the presented hyperbolic model can fit the large strain constitutive relation nicely. The initial void ratio has considerable influence on the computational large strain constitutive relations.

To prevent excessive rutting on asphalt pavements, it is necessary to predict correctly the high temperature fields in asphalt pavements with the climate information, to design adequately the pavement structures and to choose correctly the grades of asphalt binder. Based on the elementary theory in thermology, the patterns of heat exchange on asphalt pavements were analyzed in detail during summer seasons; and the two-dimensional numerical model of transient temperature fields in asphalt pavements was established with explicit scheme, which is deduced with the finite difference method. In order to understand the preliminary effects of different locations and climates on high temperature fields in asphalt pavements, the in-site experimental validations were carried out. Meanwhile, the comparison between results of prediction model and the in-site data proofs the validation of numerical model.

Based on the microstructure-mechanisms of rock materials and a simple mechanical model, a rheology damage constitutive equation is proposed by introducing generalized time defined in the space of irreversible strain and Newtonian time, and an anisotropic damage tensor of rank four. The anisotropic evolution and unilateral effect of damage as well as the effect of hydrostatic pressure can be taken into account in the proposed model. The corresponding numerical analysis is developed; and the creep, inelastic and damage behaviors of claystone are analyzed. It shows that the calculated results agree well with the experimental observation. The influence of stress level on the creep can be well described with the model.

The foundation pit landslide of a tall building is analyzed. The waterproof measure of supporting project has deficient. The top and foot of the foundation pit slope is not closed by concrete coverage. The rainfall enters the soil under the coverage. So the soil is scoured out. The prestressing force of the bolt lost. At last, the foundation pit landslide occurred. Limit analysis by finite element method and dichotomy are combined with together to used in foundation pit slope. Based on the mechanism of limit analysis, latent slip surface and safety factors are obtained.

When boundary conditions are as follows: they are all stress ones, or contain displacement boundary condition but only contain zero-displacement boundary condition on the plastic region’ boundary (with no limitation on stress boundary condition), Reference [1] obtained important conclusion of elastoplastic stress field. By introducing an elastic body that has the same geometric shape and boundary condition as those of the plastic area of the problem under consideration and making use of the uniqueness theorem of elastic solution, the conclusion of Reference [1] was proved again in this paper.

Based on the fundamental principles of soil plastic mechanics, the formulas calculating the squeezing stress in the expansion of cylindrical cavity during pile-driving are deduced taking the soil structural damage into account. The three-dimensional distributions of the squeezing stress and the terminal expansion force during pile-driving are analyzed. So the shortcoming of the classical cylindrical cavity expansion theory can be overcome. The mechanism of soil squeezing during pile-driving will be revealed more clearly. Finally, the pore pressure due to pile-driving is discussed based on Henkel’s equation.

Based on the mesostructures of heterogeneous materials to partition meshes and using polygonal elements in finite element analysis, the numerical simulation based on real structures of materials can be realized. A geometric construction method of polygonal interpolation is presented. Constructing an aided polygon, the basis function expressions of polygonal interpolation are given using divergence theorem. The equivalence of geometric construction method and barycentric coordinates method by Floater is proved. The construction methods and properties of Wachspress interpolation, Laplace interpolation and mean value interpolation are compared and analyzed.

The stresses of the most dangerous point on the edge of a cavity are calculated by using of element free Galerkin method(EFGM). The stability of rock-salt roadbed with single cavity is analyzed. The critical loads are presented for different depths of cavity, The numerical result shows that EFGM is not only effective, but also flexible for the stress intensity problem with one cavity.

The concrete cutoff wall is a technology used in reinforcing sick dams more usually in recent years. The advanced FLAC3D method which is based on 3-D explicit finite difference method, is used to simulate the effect and working state of earth-rock dam reinforced by concrete cutoff wall. At the meantime, the differences in the stress and strain etc. between the rigid and plastic cut-off wall are also researched; and then that provides the reference to the use and development of this technology.

On the base which the roughness profile is model as a series of irregular shaped, triangular asperities, the shear failure mechanism of tooth-shaped joints was studied. The shear strength equation was derived, in which the surface profile of joints were considered.The relationship between equivalent cohesion and joints cohesion was established. The equivalent coefficient was proposed and the rule of the coefficient was studied. By discussing the equation under low, medium, high normal stress, some conclusions were drawn.

A 3D nonlinear FEM is used to simulate the strain and stress of Niuniu concrete faced rockfill dam during construction and impounding time; and unified the index curve which academician Shen Zhujiang proposed to analyze the rheology of dam based on the FEM program written by our group. So in each time the stress and strain of dam body can be obtained and the influence of rheology on dam stress and strain. while calculate the displacement of faceplate slot and peripheral slot, 3D Submodel method is used. Base on actual construction and impounding process, amend the displacement of dam upriver surface before each stage faceplate being built. face-to-face fiction contact element between concrete face and dam body to simulate the strain and stress of the faceplate. So some helpful suggestion can be provided for the further optimizing design of the dam.

Potential energy of water phase in unsaturated soils and corresponding change during the process of water be soaked into initially completely dry soils are discussed qualitatively. Then, based on water phase continuity requirement, generalized Darcy’s law and Gardner’s empirical equation on relationship between coefficient of hydraulic conductivity and matric suction, formulas are established and solved by finite difference method to calculate matric suction in unsaturated soils along depth in the condition of one-dimensional steady flow, respectively for permeation and for evaporation. Not only matric suction, but also head and coefficient of hydraulic conductivity can be attained easily by the proposed method.

Stress paths have material effect on strength and deformation behaviors of soil. The suction controlled stress path study of unsaturated soil is more complex than saturated soil under triaxial compression stress state. The strength and deformation behaviors of unsaturated soil can be approximately described by elastoplastic constitutive model that was proved by abundance academic and test researches. It is an effectual academic study method that adopting elastoplastic constitutive model of unsaturated soil to simulate unsaturated soil suction-controlled stress paths tests under triaxial compression stress state. Barcelona model is used to process the study; and the results show that the stress paths have important effect on strength and deformation behaviors of unsaturated soil under suction controlled triaxial compression stress state.

In the field construction, the expansive soil cut slope is very stable, but during or after a rainfall, it is destroyed. After the destroyed part is dug, the slope is destroyed again when a rainfall comes again. It happens again and again according to the above course. So the paper gives a water expansive model of expansive soils. The model memorizes the max water content in the history under some certain stress, and it has stored much energy. When the stress is removed, the expansive soil is deformed only according to the stress-strain curve of the general soils. But when a rainfall comes, the model begins to show its nature of expanse. The paper gives the stress-strain curve and the elastic modulus formula, which is different to the one of the before elastoplastic hardening model, and the difference is obvious; and it is obtained after removing the strain-strain curve of the general elastoplastic hardening model to the left some distance.

Based on the theory of unsaturated soil, seepage and stability of slope under rainfall infiltration are studied with finite element method. It is shown that the matric suction reduced by rainfall infiltration is the key factor which causes the slope stability decreased. Furthermore, the influence of different values of matric suction and different locations of cracks on slope stability is analyzed. Results show that the greater values of matric suction, the greater factor of safety (FOS) of slope at primary state of rainfall, while this effect will decreased with rainfall went on. It is convenient for rainfall infiltration with cracks, so the FOS decreased by cracks in general. The FOS controlled by downstream cracks of slope at primary state of rainfall, while the upstream cracks will become more important to FOS with continuous rainfall.

According to the rule of soil pressure varying with displacements, a new model of calculating soil pressure is presented. Combined with the newly presented model and the interaction of ring beam and piles, a computation program is made in Matlab Language. A typical case is calculated by the program, which verifies the advantage of the method.

Concerning the rare study on mechanical properties of phosphogypsum, the relationship of strength with confining pressure is investigated by the triaxial compression experiments with high confining pressure. From the experiment results, it is found that the strength will increase with the increasingly confining pressure and the tendency is very obvious. It is dangerous to use the strength parameters obtained from the conventional triaxial compression experiments to analyze the stability of high phosphogypsum dam. Taking a high phosphogypsum dam for example, the stability of the dam is analyzed, And the results indicate that the safety factor would obviously decrease if the strength reduction of phosphogypsum in high confining pressure were taken into account. A conclusion is drawn that the strength reduction of phosphogypsum in high confining pressure is evident, and it is necessary to consider the strength reduction of phosphogypsum when analyzing the stability of high strength reduction of phosphogypsum dam.

Based on the convergence of surrounding rock of Long-tan tunnel during excavation, a grey forecast model of GM(1,1) is established by dealing with a list of data on time-dependent relative displacement with randomicity and undulation. It is used to predict the future convergence of surrounding rock deformation. The formula of velocity is gained by analyzing the prediction displacement. The time of stability of surrounding rock is forecasted by this formula. The forecast results of two sections are close to the data actually obtained from monitoring.

The conception of equivalent stiffness is used to simulate structural damage severity. Using this approach, an analytical model, which includes three damage parameters（damage location, damage severity, and the length of damage）, is developed for fixed-fixed beam. Solutions for the bending moment along the fixed-fixed beam under dead load, for both the undamaged state and damaged state, are obtained by solving the equations which are deduced from the theories of plane bending and approximately differential equation of flexural. The change rules of bending moment for damaged fixed-fixed beam are summarized from comparing the numerical values. The purpose of this paper is to lay groundwork for future research about structural health monitoring and damage identification.

Soft foundation treatment is a key technology problem in highway construction; dry jet mixing pile is often applied to soft foundation treatment. By the in-situ test, the dissipation laws of pore water pressure in the course of dry jet mixing pile construction and the developing laws of soil strength along with time are studied. According to the numerical simulation analysis, the developing laws of pore water pressure along with depth and horizontal distance are obtained. The developing laws of the soil strength because of disturbance by the dry jet mixing pile construction are revealed from the test aspect and theory aspect.

On the basis of summarizing the numerical simulation of groundwater systematically and combining Jinan fissure-karst water system, a two-dimensional unsteady flow model is established by using the finite difference method and the finite volume method. And then the dynamic changes of groundwater in the spring field is asseseed. Some conclusions are drawn so as to provide efficient analysis method for the evaluation and management of groundwater resources of the Jinan spring field; and provide significant reference for the evaluation of scientific management of local groundwater resources.

The observed values of the embedding pressure sensors aren’t the actual stress values in the medium , for the sensor isn’t coupling with the surrounding medium. In this paper, The structure of pressure sensor is described firstly, then combined with the by using numerical analysis of finite element method , the real load feature and stress distribution of pressure sensor are obtained. Finally, a method to modify observation data is proposed so as to provide a theoretical foundation for applying pressure sensor correctly.

The problem of one-dimensional consolidation of soft clays under time-dependent loadings taking account of rheological characteristics of soils is studied. By using Laplace transform, the solution in the condition of constant loading is obtained. Based on this solution, the analytical solution of time-dependent loading is developed using the integral method. By the analytical solution, the influence of some major factors on the consolidation behavior of soils is investigated and the relevant results are presented in graph forms. It is shown that the form of the consolidation curve is affected obviously by ?1 and that the degree of consolidation and the speed of consolidation reduce with the decrease of ?0.

In terms of main influencing factors of seepage, a seepage real-time forecast model is established based on genetic algorithm and neural network. The model can be trained sequentially with new observed data in further application; and the accuracy of the model can be improved in less training time with the accumulation of samples. Thus, it can satisfy the demand of real-time forecast. The predicted results agree well with the measured ones in the forecast of transverse uplift pressure of Fengman Dam so as to indicate that the proposed method has high prediction accuracy and is valid and practical for seepage real-time forecast.

Considering the variation of friction angle on wall surface and sliding surface under non-limit state or limit state, the horizontal-stratum analytical method is improved. By using variant friction angle of each stratum, equations of calculating the unit active earth pressure, the resultant active earth pressure and the points of application on retaining wall are induced. It is demonstrated that the calculating results using this method have a good agreement with those using other methods and experimental observations.

Coupled hydromechanical model of unsaturated media is used to analyze the diversion tunnel #2 excavation located at the Nuozaidu Hydropower Station in China; part of tunnel site in jointed rock mass zone and water pressure around the tunnel is high. The effects of high water pressure and jointed rock mass zone during tunneling are discussed in detail. The jointed rock mass zone contains two sets of high density of parallel joints, which could be simulated by anisotropic joint constitutive model. Excavation-induced permeability changes and draining-induced saturation and permeability changes are taken into consideration. The transient coupled hydromechanical model could simulate a rapid local pressure increase, effective stress decrease, permeability changes and stability improves on excavation disturbed zone (EDZ) around tunnel during construction. Results from numerical model matches some similar foreign general experiment conclusion; and the model could be used to assess rationality and economical efficiency of tunnel construction under high water pressure condition.

A kind of layer element with thickness and anisotropic hardening-softening character is adopted to simulate mechanics and deformation characteristic of soft interlayer in dam foundation. Contact friction element with no thickness is applied to simulating the joint in rock. Three-dimensional nonlinear finite element analysis is performed for slide resistance in deep foundation. Intensity safety factor is adopted to simulate gradual destroy progress and potential destabilization pattern. A judge method for limit load carrying capacity is presented, which synthesizes plastic zone pierce method, displacement jump of typical position and energy method. Then limit load carrying capacity of dam system is gained and slide resistance is evaluated. The finite element calculation results of actual project show that the limit load carrying capacity of dam system is decided by intensity of soft interlayer. Limit intensity safety factor is 2.7.

The tectonic stress field of Houcao area in Daanshan Coal Mine was simulated with ANSYS software. The results of the numerical simulation show that the maximum principal stress of Houcao area is horizontal stress. And the trend changes of faults and seams have the stronger influences on the stress distribution of all the Houcao area. So the results provide theoretical basis to the disposal of working faces and laneways; and the choices of coal-mining method in Houcao area.

Facing up the fact that traditional earth pressure theory can not consider the effects of the displacement of retaining wall on earth pressure calculation, a new earth pressure calculating model considering the nonlinear effects of the displacement of retaining wall was set up, and influences and calculating ways of the parameters were studied. Centrifuge model tests showed that the calculating results of the model are coincident with the tests data. So the calculating model is credible, and it provides a new calculating way for earth pressure calculation.

The stress-strain relation of cohesionless soil can be modeled with Gudehus-Bauer hypoplastic constitutive model, in which the magnitude and direction of stress increment depend on not only the previous stress state, but also the bulk and direction of current strain increment. For analyzing differences between this model and traditional elastoplastic theory, the linear term and nonlinear term of Gudehus-Bauer model are investigated. The stress-strain relation of Gudehus-Bauer hypoplastic model in different original void ratios is discussed. The results show that Gudehus-Bauer hypoplastic model can consider irreversible deformation without recourse to decomposition of strain into elastic and plastic parts. This model can also embody dilatancy, strain-softening of dense sand and contraction, strain-hardening of loose sand.

Based on linear elastic assumption and ANSYS software, taking the excavation of underground powerhouse of Longtan Project for example, the dynamic stress intensity factor under blasting load and unloading of initial stress is calculated. The results show that the crack propagation and rock mass damage near borehole are due to blasting load in the process of fragmentizing rock by blasting in medium high ground stress region. But the dynamic unloading of initial stress is the key factor which induces the loose of reserved rock in medium long region and the propagation of original crack.

With the outcomes of numerical analyses of characteristics of static and dynamic for a building reservoir dam, the advantages and disadvantages of vertical-core and inclined-core earth-rock dams are compared and analysed from the aspects of stress or deformation and security of dam; and some useful conclusions are drawn. These conclusions can be for reference in constructing some similar engineerings and the design。

The clay layer substance is regarded as water-resisting layer in certain condition in engineering. Through the methods of model test, experimental research was carried out for determining methods of whether the clay layer is water-resisting layer and the distribution regularity of water pressure inside. Certain condition of clay layer for water-resisting layer is found out according to the experimental results; that is found out the relationship among the thickness of clay layer, permeability coefficient and water table height on the clay layer, initiative hydraulic slope is gained for certain clay layer, water pressure distribution regularity is also gained inside the clay layer which has been infiltrated water. Experimental results have some guidance effects for the practical engineering.

There are close relationships between the dynamic changes of seepage field in slope and the failures of reservoir slopes. The traditional analysis methodology based on saturated seepage law isn’t able to describe the dynamic changes law of pore water pressure in slope while reservoir water lever fluctuating. Based on the theory of unsaturated and transient seepage, and the representative hydraulic parameters of 3 typical porous media selected, the finite element analysis of the seepage field is conducted with respect to the ideal layered slope containing relative impermeable intercalated bed. The distributions of pore water pressure and free surface in slope are obtained. Moreover, the diachronic changes of soil matric suction and volumetric water content corresponding to water lever fluctuating are obtained. The analysis reveals that the soil saturated hydraulic conductivity, characteristic curve of soil-water, and the structural feature of slope determine the pore water pressure and free surface distributions together. The modeling results can provide evidences for the evaluating of slope stability and the design of water draining and enforcement measurement for such type slope.

The conventional approach for analysis of liquid seepage in partially saturated fracture media usually employs macroscale continuum concepts, but notable unevenness of local velocity and flux in fractured rocks has been observed in the field test. Unsaturated flow in naturally fractured rocks is generally a multi-phase, non-isothermal flow that occurs in a three-dimensional fracture network. Stochastic simulation has become a common tool for characterizing and visualizing heterogeneity on incomplete information. 3D fracture systems are approximated as 2D planar fractures that are conceptualized as 2D heterogeneous porous media. Simulated annealing algorithm is applied to incorporate data from various sources into their models by formulating a suitable objective function; and then spatial fractures are characterized.

Based on the cause of formation of frozen heave, control equation of stress field and thermal regime is established for the frozen soil. Then, by using solid phase increment theory and thermoelasticity theory, authors attain the frozen-heave force in the frozen soil, with the consideration of the interference between stress field and thermal regime. Furthermore, phase change temperature is considered as a supplementary condition of formation for ice lens. At last, a theoretical calculation method of frozen-heave is proposed; it can exactly describe the process of frozen-heave in frozen soil, with the consideration of difference between in-situ heave and segregated ice heave.

The subsidiary stress problem of rock surrounding a circular tunnel is researched. Considering the stress-deformation characteristic of the total field, and applying the technique of series expansion, the appropriate stress functions are constructed. Accordingly, the complex potentials of the rock mass are obtained. The numerical results indicate that the orientations of the occurrence of severe stress concentration are unnecessarily near the hole, and the orientations of the occurrence of weak stress concentration are unnecessarily apart from the hole. When the embedded depth of the tunnel is 5 times than the radius of the tunnel, it can be treated as a circular hole in infinite matrix.

In light of the defects of existing interface elements, a new calculation method for interface elements is put forward. The problems of considerable large error in stress calculation and large element overlapping in existing Goodman interface element can be avoided. The implementation steps of the model are given to facilitate the numerical calculation, and the method is proved to be reasonable and effective by the numerical model verification.

For soft clay which has rheological property, the selection of model is very important for describing mechanical behaviors. Classical model has some disadvantages for describing rheological property of clay; and the classical rheological model and the fractional derivative rheological model are analyzed and compared. The latter is more accurate than the former; and it has a wide application area.

The thermo-hydro-mechanical coupling of porous media has been widely used in hydraulic engineering, geotechnical engineering and underground engineering. It is expounded more comprehensively that major achievements and the latest progresses of the dynamic response and wave motion in the rock and soil. Some opinions are proposed on several key problems, concerning the development of the theory of dynamic response and wave motion in the soil considered thermo-hydro-mechanical coupling.

A 3D numerical simulation of high slope excavation in left abutment of a large hydropower station is carried out with a program 3D-?. The result of analysis shows that the tensile stress zone exists at top of slope surface after excavation; the rock mass deformation in the horizontal direction and vertical direction appears at the bottom of spandrel groove and the cable-crane platform; excavation of spandrel groove leads to unloading relaxation and deterioration of surface rock mass in the mountain No.5; and the large block above the fault f42-9 will be a potential threat; all the above will be the focal point of slope support at excavating step by step. According to analysis above, supporting measures after excavation are carried out including combination supporting measures of prestressed cable and drain to cut the water. The result shows that the supporting measure is effective, which meets the needs of project design.

Studying the friction between wall and soil has important meanings for calculating deformation of foundation pit and vertical bearing capacity of supporting structure for foundation pit. The effect of friction force is analyzed completely with finite element method. And comes to some conclusions are drawn so as to provide for reference to practical projects.

Underground engineering has characters of complexity and uncertainty, the feedback analysis for large cavern group construction needs combing several means such as experience knowledge, statistic analysis and numerical simulation. The variety methods and the process of feedback analysis are introduced, then the feedback analysis integration intelligence system is proposed based on IDSS frame including database, knowledge base, model base and reasoning machine; and the system has been developed by Power Builder and VC++. The system has been used in the feedback analysis for the underground powerhouse of Shuibuya, Hydropower Station. The results show that the systematic pattern and developing method are feasible.

The rock is a geological media that underwent distortion and destroy. The failure of rock is progressive failure process that is conduced by the inner flaws under the condition of the outside load. This process has intimate relation with the media’s inner flaws. The pilot study on the failure law of brittle rock with prefab crack is carried out by numerical sisulation, and the influencing mechanism of the cracks on the brittle rock failure is analyzed. Based on the study results, some conclusions can be drawn. In the failure process of the brittle rock with prefab crack under load, the existence of the cracks becomes the master factor that influences the failure mode of the brittle rock instead of the heterogeneity. And the distance between the prefab cracks is an important factor influencing the failure mode of the brittle rock with double cracks.

Based on the geological and mining condition of a certain coal mine, the two-dimensional finite element model is established by ANSYS, then the rational protective pillar of fault is numerically simulated.The influence of coal and fault in front of working face is also simulated by exploitation under different protective pillars. Through analyzing the abutment pressure of upper floor of coal layer is simulated; and the rational protective pillar is gained. Scientific basis is provided for practical exploitation.

The subsea tunnels all over the world are investigated; and the three methods, such as Norway experiential method, the minimum leakage method and coal cutting experience under water, are summarized. According to above-motioned methods, the engineering analogy is used to decide the minimum rock cover of a subsea tunnel at Xiangshan Harbor. The results of three methods are thought over overall. Meanwhile its geology is considered. Then the optimal rock cover is gained. To take into account the subsea landform and geology, a profile is chosen to be the reference profile. According to the design gradient of the subsea, the tunnel motherboards and the rock covers of profiles are obtained. Comparing those with the results of engineering analogy, the shortcut of tunnel is got under the safety condition by adjusting the gradient of the part of the tunnel motherboards; so the optimal scheme to construct the subsea road tunnel is decided.

This paper gives integral strata deformation pattern and slumping arch strata deformation pattern based on the strata deformation characteristics in urban subway using shallow tunnel construction method. Mechanical models, stability features, major influencing factors and settlement curves of strata are also given，which can perfectly explain the characteristics and patterns of strata deformation, and reveal the mechanics of large deformation and surface subsidence in clay soil and sandy soil. It is shown that strata deformation is usually caused by the destabilization and destruction of structure strata. The strata structures act as beam in integral settlement pattern, while pressure arch in slumping arch deformation pattern. Thereby the beam or arch stabilization is the core of ground settlement control; and respectively the emphases are strengthening beam bearing point and in-time complementally grouting in bed separation region, as well as controlling the stability of arch springing strata. With the merits of these models we can offer strata deformation control standards and environmental evaluation criterion. Based on the typical project of sector 6 and sector 3A of the first-stage subway construction in Shenzhen, good result is achieved successfully in strata deformation control of both patterns; meanwhile available suggestion is proposed on the strata deformation control standard of Shenzhen Subway as well as other urban underground works. The achievement of this paper will be the prevalent guidance to environmental control in urban underground engineering.

By using 3D finite element method to simulate the construction process of twin tunnel, the space-time effect of the deformation of surrounding rocks and the transaction between the left tunnel and the right tunnel, are analyzed and discussed. It is found that the influence region on deformation is about 2.5 times of the tunnel diameter in the case of the excavation of single tunnel. During the excavation of twin tunnel, the influence region on deformation of left hole is about 2 times of the tunnel diameter in front of advancing face, and is about equal to the tunnel diameter at the back of advancing face. Finally, the variation of maximum settlement in vault midline and location with face advancing and the effect of right hole, are analyzed.

At present, many subsea tunnels are under construction construction or to be constructed in China. Their costs are directly restricted by the minimum rock covers. Under the condition of the minimum rock covers, by applying fracture-damage, seepage and construction process model, the minimum rock covers are analyzed with the engineering geology and the water conditions of the subsea tunnel. At the same time, the minimum rock covers are affected by earthquake and blasting etc. Finally, by using project analogy method and numerical method and considering different kinds of factors effecting minimum rock covers, a better minimum rock cover can be chtained.

Aimed at phenomena of support’s being pressed to burst or be unable to work in a few fully mechanized sublevel caving longwall faces, according to the analysis of the roof structures, their movement characteristics and the dynamic stability in fully-mechanized sublevel caving face, the mechanism of abnormal pressure on support in fully mechanized sublevel caving face is studied. The conclusion is that the main cause of abnormal pressure is sliding of roof structure. Because of the difference of sliding of roof structure, there are three of abnormal pressure. According to the analysis of the pressure on support, the computation formulae of abnormal pressure on support are presented. Using the dynamic stability judgement rules of roof structures, the types of abnormal pressure on support are distinguished and the computation means of abnormal pressure are defined; and the theoretical foundation about the selection of support in fully mechanized sublevel caving face and controlling abnormal pressure at field experiments are provided.

The geological prediction in tunnel engineering, the geological disaster resulting in the design and the practice and the reason about the low precision of the geological prediction data are are expounded. The emphatic part of the geological prediction are decided through analyzing the detection data and complementary detection during the geological construction prediction. And describing of the heading face, the choice of the exploring method, the result of exploration the report and construction validation of the geological prediction method are expounded too.

In the mining area, separation layer grouting is an important technology to control the settlement, the formation and situation of separation layer is significant to exert separation layer grouting. The formation of separation layer grout needs three conditions: weaker plane shear failure, terrane integrality and lithology otherness. The criterion of separation layer formation is established from the proceeding conditions and Mohr-Coulomb criterition. The study shows that the formation and situation of separation layer is confirmed by analytic solution or numerical solution.

The rock cover depth of subsea tunnel is a key factor to the tunnel stability as well as economy and should be evaluated carefully. At present, there is no a standard in how to select it. Based on the characters of rock cover depth selection, according to the experience of subsea tunnels which have been built, empirical analogue methods have been carried to research it. Through employed empirical analogue methods into an actual engineering, reasonable rock cover depth ranges can be obtained. The methods proposed can provide reference for the design of other subsea tunnels.

The high cost of urban space has significantly increased the demand for tunnels in big urban centers. In such areas, settlement induced by the tunnel excavation may cause serious damage to nearby structures. Therefore, it is necessary to investigate effective means of controlling tunnel-induced settlements. In many countries, tunnel in soil and rock mass are constructed using new Austrian tunneling method (NATM) for its flexibility to adapt to different ground conditions and use of simple equipments. Ago, tunnel designs by NATM are generally based on empirical methods taking into account local experiences. But this method is said to be observational and cannot illustrate the construction process and the stress and strain changing. So that, with the developing of PC and numerical method, using FEM and other method have been utilized in geotechnical engineering. At first, the paper shows the principles of NATM, and illustrating the two key: excavating unloading node force on the tunnel boundary and constructing steps. And on the base of above illustration, utilizing finite element code ABAQUS analyzing and modeling a tunnel. From obtained results, it is shown that the finite element method can model tunnel constructing process reasonably.

Ascertaining the minimum rock covers of subsea tunnel is important to reduce project cost on the conditions of subsea tunnel safety. Researching the dynamic influence of tunnel blasting construction on the cover rock mass is necessary to the minimum rock covers. The effect of subsea tunnel construction using drilling and blasting method to overlaying strata is analyzed through FLAC3D numerical simulation. The influence of different subsea tunnel level and charge weight on the interface of overlaying strata is analyzed. The blasting vibration velocity history and stress vibration history at key points and the plastic zone are gained and contrasted with the result of experimental formula; synthesizing the above analysis and considering economical and safety of subsea tunnel, we suggest that charge weight should be reduced and subsea tunnel level should be descended 2 meters.

The underground powerhouse of a hydropower station lies in stiff and integrate granite expensive some fault. A lot of monitor instruments are installed during construction, and much information are received from that. Based on the complete observation information of the pumped-storage station, the deformation data of the wall rock are studied. And then the conclusion is the underground power-house are steady in principle. At the same time，the numerical model of underground house is analyzed by using finite difference method. The changing law of displacements and stresses of rock-mass is studied and the dynamic changing process is forecasted truly. The displacements from computing and observing of some points in the rock are contrasted. All of those can offer the reference to other stability analyses of large underground power-houses.

The limited depth freezing method with four-row freeze-tubes, forming a frozen soil wall to cut off water and resist the soil pressure between the undamaged tunnel and the collapse tunnel, was used in a metro construction in Shanghai. The construction was completed successfully. This paper analyses how to use the monitored data to estimate the situation of leaking brine in freeze-tubes and judge the degree of density of the filling mortar in the tunnel. The temperature field character of the frozen soil wall was analyzed and the time of active freezing was calculated. During the cleaning in the tunnel and casting the concrete wall for water cutoff at the side of Pudong, the variation of the temperature in the frozen wall affected by the construction procedure was analyzed. It can draw a conclusion that temperature can reveal the construction quality of freezing method. Through proper redistribution of the monitoring holes, using informatized construction, studying the law of the temperature variation, the safety of the complex freezing construction can be guaranteed.

Based on mixture theory and the double porosity hydromechanical coupling concept, a set of coupled governing differential equations of porous fissured media is derived. The finite element technique has been employed as the numerical methods for solving these equations by using Galerkin finite element methods. Relations relating to rock classification rating RQD and RMR are developed to define changes in effective porosity and hydraulic conductivity that result from the redistribution of strains in disturbed rock mass. A 2-D finite element program and software for solving the double porosity media coupling model is developed. Results obtained from a hypothetical example indicate that the program is reasonable and practical. The program is also used to simulate tunnel excavation; the influence of seepage effect on tunnel ground deformation and seepage field is discussed. The results of numerical calculation show that tunnel liner design is unsafe without considering hydromechanical coupling effect.

The construction of large-sized hydropower station is a kind of complicated systems engineering; and the underground carven rock’s stabilization is influenced by some factors. The hierarchy of analyzing underground carven rock’s stabilization is divided on the basis of fuzzy analytic hierarchy process. Hierarchy structure model is established; and the stabilization of four segments underground cavern rock is sorted through analyzing and comparing layer by layer. The example shows that the fuzzy analytic hierarchy process integrating quantitative analysis and qualitative analysis together takes on good reliability and practicability.

The principle and method of optical fiber bragg grating (FBG) sensor inspection are analyzed. According to the increasing development and requirement of tunnel construction engineering long-term testing, a kind of optical FBG sensor for diameter 22 mm anchor bar is put forward, designed, and fabricated for tunnel monitoring; because the electromagnetism sensor is not employed stably in rock and soil engineering monitoring. The axial strain of anchor bar can be detected by FBG on anchor bar easily. FBG anchor bar sensor is used in lab and highway tunnel. The experimental and practical results are both good. It is proved that FBG anchor bar sensor is of high precision on measurement, good anti-interference ability, long-term stability, simple structure, online real-time monitoring application of rock and soil, and so on.

The deficiencies of the traditional observation methods of coal mine stress are analyzed; a combined observation scheme of coal mine stress is presented; through the discussion of combined observation theory, observation scheme and practiceal scheme, a series of practical observation scheme is proposed; it is feasible in theory and useful in practice. The scheme is reliable to measure the rule of coal mine stress variety through the practice. And it is worth to adopt in coal mine stress observation of coal mine enterprises.

The importance and the monitoring measurement method of the highway tunnels are described. The principle and the process of intelligent back analysis are systematically expatiated. Through the real tunnel project, the intelligent back analysis of tunnel displacements is proved to be accurate and feasible; and it has important significances for the stability evaluation of tunnel adjacent rock and intelligent construction.

The ground surface settlement models caused by tunnel excavation are summarized. The discontinuity plane geological characteristics of Hongfeng doubled arch tunnel in Jin-Li-Wen Expressway are investigated and analyzed. The ground surface settlement rule cased by excavation of doubled arch tunnel in case of partial pressure is researched. The ground settlement of Hongfeng doubled arch tunnel during excavation is analyzed. The ground surface settlement models of difference excavations by step for doubled arch tunnel in case of partial pressure are built. The difference settlement of different excavation is analyzed. The ground surface settlement models testified that it forecasts the ground surface settlement of excavation for Hongfeng doubled arch tunnel in case of partial pressure and shallow overburden. It provides a theoretical basis for avoiding overmuch settlement during excavation of shallow doubled arch tunnel.

The mechanical behavior of supporting system for closely adjacent tunnels is the direct indication of its safety in the excavation of diverging tunnels; combined practical work of Miaoya diverging tunnel with small interval in Hu-Rong Expressway, the lateral reinforcement theory of inter-space rock and site monitoring of closely adjacent tunnels are introduced; based on the results, the deformation of surrounding rock and mechanical behavior of supporting system are presented; together with the study on the field experiments for blasting vibration of inter-space rock, the stability of closely adjacent tunnels is evaluated; and the conclusions obtained will devote to the following studies.

The diverging tunnel is a new promising tunnel used in communication construction in West China, Aimed at the problems involved in excavation and research of the large-span and shallow part of Miaoya diverging tunnel in Hu-Rong Expressway, excavation mechanics simulation with FLAC3D is introduced and site monitoring is proceeded at Miaoya diverging tunnel. Based on the results, the excavation mechanics analysis and site monitoring of wall rock deformation and the mechanical character of supporting system are presented; some conclusion is drawn by the analysis of classical geology part of this tunnel. The research will devote to the following studies.

Considering the laminated geologic characteristics of salt rocks in China, the stability of ZK1075, ZK1083 and ZK1099 salt caverns in Yun-Ying area of Hubei Province is analyzed by the FLAC3D interface program of the new three-dimensional expanded Cosserat medium constitutive model. Besides dealing with the effect of the stiffness difference between mudstone and rock salt on elastic characteristics of the composite, it also considers that displacement correspondence between layers results in mudstone’s fracture firstly and then leads to the deformation and failure of composite. The results show that the mudstone interlayer in laminated salt rock in Yun-Ying area will restrict the deformation of rock salt owing to its larger stiffness and strength; and the presence of mudstone interlayer plays an active role in the stability of the oil/gas storage.

Taking one shallow-buried air-raid shelter of which buried-depth is about 6m to 13 m for example, this paper simulates the failure laws and the failure mechanism of the tunnel-roof which has different spans and rock characters and different loads using the FLAC; determines the failure fields of the roof rock masses of the tunnel; and then studies the sensitive rock mass of the arch. The results show that the tunnel roof has some bearing capacity when the span is 2 m and the roof-rock is mudstone; and the tunnel collapsed until the load reached 0.7 MPa; but if the span is 3 m, the tunnel collapsed when the load reached 0.33 MPa. If the tunnel roof is pebble stratum, the tunnel collapsed under the overburden pressure even it has no loading. This study has practical meanings to the similar study about the stability of the surrounding rock masses of shallow-buried underground engineering.

According to the geological section of the Xiangshan Harbour subsea tunnel, the tunnel axes of nine sections selected are researched and analysed. The appropriate tunnel axis of each section is fixed on through lifting and shifting the tunnel axis according to the thickness of bedrock. The paper applies the finite element program of fracture damage model to analyze different cases of the sections. Analyzing their damage zones, plastic zones, stress state and displacement variation in all the cases, the stability of the tunnel is studied. Based on the above analysis, the most appropriate tunnel axis position of every section is proposed.

Based on continuum mechanical model of rock mass, a new reliability analysis method is suggested to obtain an explicit expression which can fit practical needs, the new method makes it possible to use commercial FEM code and it differs from response-surface-method(RSM). The suggested method is applied to analyze a circular tunnel considering variation of mechanical parameters. Mechanical parameters c, E, ? and lining thickness D is considered as random variables. The variation law of axial stress in concrete lining with the variables is obtained; and multiple linear and nonlinear regression methods are applied to obtain the final expression of the axial stress in lining with all the variables. The sensitivity and reliability analysis of a circualr tunnel is made with the method. Some conclusions are drawn from the research work.

Longtan tunnel, a key part of HU-Rong Expressway engineering including many geological problems such as shallow cover, unsymmetrical pressure, water rush, mud rush and rock burst, is a representative of long and broad expressway tunnel under complex geological conditions. It is very difficult for engineer to build tunnels with shallow cover and unsymmetrical loading. The design and construction of Longtan Tunnel are described from safety point of excavation and support. FLAC3D is used to simulate the excavation and supporting process of the exit section of Longtan Tunnel under the condition of shallow cover and uneven pressure. Some conclusions are drawn through analyzing the characters of stress and displacement fields and plastic zone of surrounding rock after excavation. It will be useful for the project construction.

The internal force of Laoyingzui tunnel along Funing-Guangnan Highway in Yunnan Province is analyzed using the finite element method. The reasonable tunnel inner outline is obtained through adjusting the connecting method between invert pattern and curved wall.The model is developed based on structure and rock type; and the wall rock resistance is considered. The internal force of original design model and optimized model are compared and analyzed. The results provide a theoretical reference for section design of large-span tunnel.

Underground openings lead to the strata subsidence, which damages various installations, such as building, pipeline, road, bridge, and water and agriculture equipments. This research presents a suggestion that the GIS technology is employed to design the underground openings plan in order to insure the lowest ground environment damage. In addition, the reliability and necessity are discussed; the data processing for visible decision system of underground openings and related key technology are studied as well; and eventually, the E-R database model is established.

Guantouling tunnel is the key project of Wenzhou-Fuzhou railway line. With 36 degree of planar angle，it crosses under Tong-San expressway tunnel. The space between the crown of building tunnel and the floor of existing tunnel is only 2.91 meter. Based on the fact of construction，the mechanical behaviour of rock tunnel excavated adjacent existing road tunnel is studied by 3D finite element numerical simulation method. The research demonstrates that deformation of surrounding rock and the disadvantage distribution of structure stress of the existing tunnel are remarkable. Therefore，it is necessary to take some reinforcement measures to guarantee safety of adjacent existing tunnel. According to the results of numerical simulation，the excavating method，support parameters，measures of vibration reduction and vibration isolation during construction are analyzed and discussed.

Based on flexure theory and inharmonic relationship of deformation of rocks, the criterion of hard roof separation was built. And the influence of homologous parameters on roof deformation was given. Using the technology of telemeter measurement to monitor rock separator in goaf, the conclusion can indicate: the system of telemeter can monitor effectively the separation information of roof rock. By anglicizing the curve monitored, the position of roof where separation happens can be confirmed; and the thickness of cave of roof would be predicted. Using the information monitored by the system of telemeter before roof cave, some prevention can be practiced to protect the safety mining under hard roof.

During tunneling, geological logging and rock mass classification are two major tasks to be concerned, so tunnel driving face image analysis is essential. Traditional analysis is time-consuming, costly and the effect is different with different operators. While conventional approaches are limited, graph and image processing and 3D modeling technology were adopted for tunnel driving face imaging. Tunnel driving face geology image system (TFGIS) was designed to manipulate tunnel driving face, so that rock edges and rock characteristic information can be acquired, by which rock mass was classified. After processing a series of driving face images which were snapped by tracking when tunneling and marking corresponding rocks between two adjacent driving face images, according to rock corresponding relation, 3D tunnel model was built up, which can be regarded as reference information for tunneling.

Amberg Measuing Technique Ltd.(Switzerland) has developed the newly TSP 203 plus system and patented the compact, which is a tunnel seismic prediction equipment. It was specially designed for tunnel geologic advanced prediction. This paper introduces the technical characteristics and basic principle of advanced geological prediction. Based on the application examples of Longtan tunnel of Hu-Rong Expressway, the system’s practicability, believablity and the important effect in directing the construction of the project, are analyzed in detail.

Both high technology and high risk are involved in construction of the subsea tunnel, especially in poor ground condition sections. Xiamen Xiang’an tunnel is the first subsea tunnel in China mainland district. The tunnel is designed as a three-tube tunnel with 6-lane shuttle and the deepest point about 70m under sea level, built by means of boring and blasting method. The stratum of site is mainly composed of granite with some poor ground conditions including completely or strongly weathered granite in land and shallow section near to both portals as well as several significant faults in seabed. It is very important to achieve risk management in poor ground condition sections during tunneling in this case. Both the principle of risk occurrence and the method of risk evaluation for the construction of subsea tunnels are discussed based on the basic theory of risk analysis and evaluation. According to the geological prospecting, structure design and planned construction method in detail design phase of Xiamen Xiang’an tunnel, both typical geological risks and representative construction risks during tunnelling in poor ground condition sections were identified and evaluated by means of the method proposed in this paper. Countermeasures for reducing the risk level were proposed in order to implement a risk management to ensure the safety and quality of tunnelling.

The power tunnel of Tibet Road in Shanghai is the most difficult pipe-jacking project in China with long distance and large diameter. The tunnel cross through Suzhou River, underground pipelines and area of dense buildings, especially the underground passage of subway and the existing subway line 2, so it’s vital important to protect the surrounding environment when the pipe-jacking construction. Based on the construction of the tunnel, some key techniques are studied by laboratory test, numerical simulation and field measurement. The key techniques such as accuracy of pipe jacking, slurry sleeves and settlement control and their applications are described. The results indicate that the techniques can ensure the completion and achieve the demand of environmental protection.

Back-filling grouting, a special craft adopted by the construction of shield tunnel, enwraps the pressure transducer embedded on the surface of tunnel, whose effect on pressure transducer will determine the reliability of the monitored pressure. On the basis of the mechanical test of backfill grouting, the finite element model considering the hardening of grouting has been established; and the effect of the hardening of backfill grouting on monitored pressure has been analyzed. After it is injected into the shield tail gap, which is in the status of fluid in short period, the backfill grouting has strong ability of adjusting non-uniform settlement and non-uniform stress of the local soil near the pressure transducer, which leads to the approximation between the monitored pressure and the actual one. So the matching error of pressure transducer on the surface of shield tunnel is far less than the one of the common underground structure.

The ground surface settlements induced by the construction of subways using shallow tunnel construction method are hardly avoidable. As the cross-sections of subways are very large most of them adopt partial-face excavation method. So it is possible to use deflection distribution control method to distribute the final ground surface settlements into every construction stage and make the ground surface settlement control standard for each construction stage．In this way we can achieve the aim of integral control by controlling in every stages. But it is often not acceptable to use the parameters from geological exploration in numerical simulation which is relied by deflection distribution control. So back analysis is used as a complement method in getting the parameters adapt to numerical simulation. This paper describes the characteristics of direct back analysis, the qualification for modeling and the procedures for analysis. Application of a real subway showed that the proposed system could successfully forecast the ground surface settlement and approve the practicability of the deflection distribution control method.

The swelling rock usually induces surrounding rock mass be extruded largely or floor lift by time even the support and surrounding rock mass be damaged or destroyed in practice. The geologic characteristic of the tunnel No.7 for Shanxi Wanjiazhai Yellow River Diversion Project is sandstone and mudstone distributing interactively and has 3-4 layers swelling rock through the tunnel. Numerical analysis with viscoelasto-plastic model has been done to analyze the process of excavation and support procedures. The numerical results show that swelling deformation has high effect on stability and mechanical behavior of support structure. Therefore, the displacement, stress and strain, seepage pressure and water pressure should be measured during the tunnel operating.

Finite element method(FEM)is adopted to back analyze initial geostress field around the underground power house of a hydropower station. Comparisons of different opening's spacings, different excavation sequences and reinforcement effect are made.The calculation result shows that after optimization, the openings’ layout, construction sequence and support parameters are safe and rational; the main openings are stable well.

Based on numerical simulation, the construction scheme of Xiamen subsea tunnel is optimized. Under conditions that lateral pressure coefficients equal to 0.6 and 0.9, firstly three common construction methods that are method of whole section excavation, scheme of upper and down benching and bench tunneling method are analyzed; the result that method of whole section excavation will slightly disturb the surrounding rock is gained compared the displacements of keypoints and the distributions of plastic zone on the surface of wall rock; finally the conclusion that the reasonable bench pace between upper and down benches is around 10 meters is proposed by analyzing tunnel stability under different bench lengths. The conclusion can direct the construction of tunnel better.

The main process of using ADO(ActiveX Data Objects) is introduced by means of Visual C++. The usages of three most important objects (Connection, Command, Recordset) within ADO are illustrated in detail. ADO and Visual C++ are proved to be very flexible and powerful tools in database application coding. All examples are taken from the monitoring information management system that authors developed previously for underground powerhouse.

The coal mining under seabed has great importance and long strategic significance on the development of coal industry in China, which indicates that the coal resources exploitation has entered into a new history period of coal mining under seabed. Through the forecast research and the test of the actual measurement, the paper opens up the movement rule of cover rock when the mining technology of the top coal caving is adopted in the soft coal bed. It establishes the foundation on achieving safe coal mining under seabed with high efficiency.

Based on the section tunnel construction of M6 rail transit project No.Ⅸ bid in Shanghai, the sensitivity analysis of construction parameters were carried out. During the construction, the parameters of cabin pressure, grout volume of shield tail, advance velocity were rectified designedly. The layered settlement of transverse and longitudinal sections induced by the construction of double-O-tube shield (DOT) in soft clay region was monitored continuously in-situ. The conclusion can be as reference for optimizing of the construction parameters, lessening the extent of environmental influence of soil engineering.

Based on the underground structure scheme of Longtan Hydropower Project, lots of elastoplastic numerical analysis were conducted considering modulus of deformation, layout depth of underground opening, height of main power house, coefficient of lateral compressive stress and spacing interval of underground houses as the mainly mechanical parameters that influenced the stability analysis of underground caverns. The mathematical statistics method was employed to investigate the displacement variation law of key point surrounding house periphery and found the forecast model. Then the forecast model was used to analyze the engineerings. It is shown that there is a better agreement between theoretic result and monitoring result in situ[1].

Feedback analysis technology has been widely applied to underground engineering, and how to analyze the measured data efficiently is a hot topic to engineers. In this paper, two kinds of methods to study the data are discussed. One is to analyze the relationship between measured data and rock mass structures theoretically; the other is using statistics to get information of the numerical characters from measured data. According to the information got before, adopting variable metric method and FEM, the stability and deformation of the surrounding rock can be forecasted. Applying the methods mentioned above to the practical engineering, the predicted results preferably reflect the behavior of the surrounding rock’s deformation as going on of the power cavern excavation. Then an efficient method is provided for the design and construction of underground caverns.

The ways of deformation prediction of tunnel are divided into the method of the static analysis and the method of dynamic analysis on the basis of reviewing the researching methods existed. The static analysis is made up of Peck theory system; the analytic solution respectively considering of elasticity, plasticity and viscoelasticity, the theory transplantation method and expert system. The method of dynamic analysis include kinds of numerical analysis, model method, timeseries method and neural network intelligent prediction method. Peck Theory system representing with Peck formula, is continuously improved and perfected subsequently. Theory transplantation consists of the stochastic analysis method and fuzzy mathematics model, the regression analysis method and so on. This paper discusses advantages and defects of every method; and simultaneously the tendency of studying are presented.

A research on increasing mining upper limit is important for coal mining, which can fully utilize coal resources and release most of the mines from the tension of limited successive exploitation. Based on the hydrologic and geologic data and data of nearby mines, taking the N2601 working face of Tianzhuang Mine for example, water resources of the producing area and water-existing character of the floor are analyzed; based on the plastic strain of the cover rock, the height range of caving zone and water flow fractured zone are analyzed through numerical simulation; finally, the upper mining limit is obtained by synthesizing the numerical simulation and exploitation regulations.

Ground penetrating radar(GPR), a new electromagnetic instrument, has been quickly developed to meet the requirement for fast probing underground obstacle, precisely. The mechanism of underground pipeline detection with ground penetrating radar is studied; and equation of the curve is deduced. By the detailed analysis of example, the method to collect radar data and interpret the radar profile under complicated condition is studied; the processing method and experience such as one-dimensional filtration, migration processing and time-depth conversion are introduced; and it is proved that the method is feasible and it has good foreground, in application.

During the excavation of tunnels in saturated soft soils, pressurized bentonite slurry is often used to support the tunnel face. The slurry should form a filter cake, which is used to transfer the support pressure onto the soil. This filter cake is constantly removed by the cutter head of the slurry shield and slurry will infiltrate into the soil while the filter cake rebuilds. This results in a decreasing of the support effectiveness of the slurry. To quantify the influence of these decreasing of the face stability, an infiltration model has been incorporated in a limit equilibrium analysis. The decreasing of safety factor of face stability according to the permeability of the soil in front is analyzed. The slurry pressure calculated with this model has been compared with field measurements. It is shown that the slurry pressure needed is significantly higher, compared with full-membrane calculations.

Combining with the engineering example, introduces the main constucion techniques, such as advance geologic forecast, precaution way of high pressure water blow-out and the curtain grouting blocking, which are adopted to deal with the high pressure water blow-out in the extra long tunnel. The paper also analyzes and discusses the construction process of the tunnel in the zones rich in karst and water. The available construction project is put forward.

The authors use FLAC3D to carry out simulation analysis in underground power house of Ertan Project. FLAC3D is a three dimensional explicit finite-difference program. The authors consider the seepage factor which influence the stability of wall rocks and do lots of numerical simulation analysis with approximate three dimension. Systematical analysis of displacements of key points of side wall and systematical analysis of the plastic zone of the main cavern are carried out. The authors draw some disciplinarian conclusions from the systematical analysis. These conclusions will provide some useful reference for the study of large-scale underground cavern groups.

During tunnel construction, the superstructure and pile foundation of buildings, stratum, tunnel construction are in an interaction system. Functional mode of each section results in cooperating and interaction. So, they should be considered comprehensively. Firstly, soil is interaction medium of the tunnel and pile foundation. Constructing tunnel at shallow depth damages stratum. And stratum deformation is delivered to adjacent piles, which result in the reduction of pile foundation bearing capacity. Load fluctuation is transferred to the superstructure by pile foundation. Then sedimentation and deformation of adjacent structures is generated. Therefore, the crux in tunnel construction is to make the superstructure safety by analyzing and controlling for the existing pile foundation. Based on detailed discussion about the interaction of the superstructure and pile foundation of buildings, stratum, tunnel construction, pile deformation mechanism and grouting reinforced mechanism, the 2D－Sigma code is applied to simulate effect of existing pile foundation induced by shallow tunnel construction from Yonghegong Station to Hepingli North Street Station interval of line No.5 in Beijing. The universal law of pile foundation deformation is obtained; and necessity of grouting reinforced stratum and related processing parameters in construction are suggested by analyzing front-to-back response of pile foundation. Finally, based on analysis of comparison between numerical results and field measurement results for pile foundation deformation, their law is quite similar. Research shows that grouting reinforced stratum is effective for reducing deformation of pile foundation and making superstructure safety. The achievement will guide subway construction later.

The tunnel excavation generates soil settlement around the pipeline, and causes the pipeline to deform and suffer bending moment. The Loganathan’s formula is used for predicting the soil displacement at the pipeline level; and the equivalent model of the forces acting on the pipeline is given. A Winkler solution is used for estimating the bending moment for the pipeline affected by tunneling. A case is analyzed; and the solution is compared with an elastic continuum solution and Attwell’s solution. The results show that the method is valid.

In order to research the unloading property of the marble in the course of excavation, the different modes of the unloading experiments on marble which are come from the seepage tunnel of Liangshan Yalongjiang Dahewan Jinping Water Power Station in Sichuan Province have been done by hydraulic pressure servo rigidity rock mechanics experiment system MTS815.04. The results of the experiments show that: on condition of keeping the principal stress difference invariant, when the confining pressure decrease, the axial strain will increase after decrease, but the elastic modulus first increase before decrease; on condition of keeping the axial displacement invariant, when the confining pressure decrease, the elastic modulus of the samples first increase, then decrease after reaching the peak value; but the axial stress is always decreasing; the Poisson's ratio obtained from the unloading experiments on condition of keeping the principal stress sum invariant is greater than that obtained from the routine triaxial test; but the marble strengths obtained from two experiments haven’t a clear distinctness.

The salt rock layer and the soft mudstone layer with salt, which have the low permeability, are usually the sealing layer of the large-scale oil-gas pool in the oil geology exploratory engineering. Thanks to the creep behavior of salt rock, the drilling technique in the salt rock layer becomes the difficult problem of drilling engineering. Based on the measured result of the drilling hole diameter between the different time, the creep rates of the rock layers in the deep stratum are obtained. The creep rate of the soft mudstone with salt is maximal. Secondly is the salt rock layer. The exponent creep constitutive law is employed to analyze the creep rate of rock layer in the three-dimensional numerical method. The creep parameters of salt rock and mudstone with salt are obtained. The parameters can be used in the optimizing analysis of the drilling mud density.

With the development of underground space in Shanghai, the ground freezing method is more and more widely used in tunnel construction. In order to avoid the problems of geological disaster which may happen in the freezing construction, it is necessary to do more researches on the physico-mechanical characters of Shanghai soft soil under freezing and thawing action. The characters of three kinds of soils from a certain project in different states (original state, freeze-thaw state, secondary freeze-thaw), are stadied; and the change rules of soil characters under secondary freeze-thaw action are educed. The results will be beneficial to the safety of the tunnel construction.

Shear strength parameters of soil-structure contact face are essential to soil-structure interaction subject. Experiments on soil-brick and soil-concrete contact faces by direct shear tests are conducted by direct shear tests, respectively. Effect of the decreasing contact area is verified during soil inner shearing tests. The experimental results show that friction angles of the two kinds contact faces decrease with increasing soil water content. On the other hand, their both cohesion forces and shearing strengths appear scissors shape relationship with increasing soil water content. Analysis also indicates that the soil-structure contact face behavior depends strongly on structure hydrophilic property. The experimental research results the good foundation for relative engineering design.

The complex characteristics such as noncontinuity, nonuniformity, anisotropy and uncertainty, which cohesive soils show in macroscopic scale in engineering, are fundamentally dependent on noncontinuity and uncertainty of soil microstructure. Based on the former research and lots of microstructure quantification experiments, we want to obtain variation character of soil microstructure, study change regularities of structural parameters under continuous loads and combine them with macro physico-mechanical behavior of cohesive soils; thus we can explain and grasp the engineering characteristics from soil microstructure.

Wellbore stability problem in shale is a very complex and worldwide problem in drilling engineering. Core chose in the test is shale in deep strata from Shawo section in Zhungaer Basin ,which collapses seriously. Based on experiment of measuring strength parameters such as cohesion, angle of internal friction, elastic modulus, Poisson’s ratio of shale in different water contents; and regression analysis of experiment data wad made; the relation between water contents of shale and its strength parameter is obtained. And the distributing rule of water content in shale is deduced in virtue of seepage mechanics theory. The research result provides the basis of experiment and theory for calculating hydrating stress in wellbore adjoining rock and evaluating wellbore stability.

The standard absorption moisture, as one of the three discrimination indexes recommended by specifications for design of highway subgrades (JTG D30-2004), its applicability in Hefei expansive soil classification is discussed; and the correlated character with liquid limit, plasticity index, free swelling ratio and the content of colloidal particle less than 0.002 mm are presented. It has been approved by a lot of laboratory tests that the standard absorption water content can reflect the swelling potential level of Hefei expansive soil, but the criterion suggested by the above specifications is unsuitable. A certain dependence relation exists between standard absorption water content and other discrimination parameters; square values of correlation coefficients is from 0.468 to 0.663. In brief, standard absorption moisture can be the discrimination index because it can explain the nature of the expansive soil.

The high density resistivity imaging is a geophysical survey method, based on the difference of rock masses or soil masses in electric properties. Its basic principles and system structure are introduced. In the light of an instance which measures the gliding mass depth and the bedrock surface shape of a landslide in the Three Gorges Reservoir area with the high density resistivity method, the applicable conditions and the fieldwork technique of the high density resistivity method, are discussed, and the resistivity distribution section images are interpreted combining borehole logs and engineering geological surveying data. It suggests that the high density resistivity method is an efficient survey method if it is combined with the conventional survey methods. And the geological resistivity distribution images generated by the self-contained data processing software are direct and distinct, and its qualitative and quantitative interpretation is reliable. The inferred parameters of the landslide accord with the reality. It is confirmed that the high density resistivity method is suitable for landslide survey very much when it is combined with other methods.

The equivalent frost-heave force model experiment of tunnel in frozen earth region including lining types of bending wall, straight wall and rotundity and considering influencing factors consist of constraint conditions, thermal insulation material and containing water status etc., are described in detail. Distribution characteristics and quantity value of frost-heave force around the tunnel lining and structural internal force caused by frost-heave force, are obtained by analyzing the experimental results. Comparing with the magnitude of frost-heave force of three lining sections, the frost-heave force value of straight wall lining section is greatest, the value of rotundity section is smallest, the value of bending wall lining section is middle of them. The frost-heaving force distribution characteristic of bending-wall lining section and straight wall express distributing load configuration, the greater value of the former occurs on arch foot and inverted arch foot, the greatest value of the latter occurs on side wall, the quite greater force on walls and bottom board is disadvantage for lining structure.

In order to study the inside changing regularity of cement-soil mesostructure and its effect on engineering characters, by the experiment of mesostructure change of different earth material cement-soil at different conservation temperatures and under uniaxial compression, to research the evolvement regularity of cement-soil mesostructure under load. Configuration parameters of mesostructure can be obtained by using the Geoimage software, and to make the quantitative analysis. The evolution charaters of proportion of pore surface area, grain discontinuity distributy, grain roundness, grain orientation, pores orientation and Euler number, and its action on compactness, cohesion, compression resistance of cement-soil can also be obtained. It’s certified that though soil sample isn’t failed, its mesostructure configuration and parameters are changed obviously; consequently engineering characters of cement-soil is effected apparenly.

Unconfined compressive strength tests have been done to analyze the influence of the content of organic matter, cement and gypsum on the strength development of cement stabilized soil and XGL2005 stabilized soil respectively. The results indicated that the strength of XGL2005 stabilized soil is higher than that of cement stabilized soil; and the strength increasing ratio of the latter is larger than the former. Combining the strength tests and the SEM tests, study had been done on the corresponding relationship between the strength development and the microstructure variation of XGL2005 stabilized soil.

Brazilian and axial tension tests were carried out with 7 rock types and 2 groups of concrete samples, with a test apparatus of direct tension developed by the authors. The result shown that the strengths of Brazilian tests, SB, were greater than the strengths of direct tension, ST, for all rock (concrete) types tested, with the ratio of SB/ST varies among 1.06 and 1.97. The Coefficients of variation of the tested data from direct tension were generally greater than those from Brazilian tests. Corrections on strength values of Brazilian tests were performed following the research results of Sundaram et al. (1980) for the rock types having Young’s modulus in tension, ET, much smaller than the modulus in compression, EC. This makes the SB/ST ratio smaller and shown that the difference between ET and EC was one of the reasons of making SB greater than SC. However, it can also be concluded that, the difference between ET and EC was not the only reason of making SB/ST difference, since the SB/ST ratios for some of the tested rock types were the largest ones while their differences between ET and EC were smaller.

The test of quantification of rock mesostructure is designed based on damage mechanics and stereology theory. Some relating issues such as specimen preparation, experiment equipment and experiment routines are settled down. The scanning electron microscopy (SEM) is used to investigate Jinping marbles in Sichuan Province and thousands of mesostructural images are obtained. Then, SEM images are transferred into binary images by using digital image processing and compiled program; and the microcracks’ information such as length, angle, width, area, perimeter, etc. is obtained from the processed images by using functions. Finally, the information of rock mesostructure is statistically analyzed; and the statistical law of every parameter is obtained; it’s import to the research of macro-damage of rock.

The swelling, swelling pressure and moisture dependent shear strength of expansive soils pose serious problems to civil engineers. Disposal of large quantities of fly ash, which is an industrial waste, poses a major ecological problem. This paper studies the efficiency of fly ash without lime as an additive in improving the engineering characteristics of expansive soils. An experimental program has evaluated the effect of fly ash content on the particle size distribution, atterberg limits, specific gravity, plasticity, compaction, free swell index, swell indices under non-compression and with an axial compression of 50 kPa, swelling pressure and axial shrinkage percent characteristics of expansive soil. The plasticity index, activity, the optimum water content, the maximum dry unit weight, free swell index, swell potential, swelling pressure and axial shrinkage percent decreased with an increase in fly ash content. It is found that with the increase in the curing time, the swell potential and swelling pressure reduced. The unconfined compressive strength test results show that there is no remarkable change in the unconfined compressive strength of the soils immediately treated with fly ash alone. However, 7 days curing brings a remarkable increase in the unconfined compressive strength.

A cellular automaton method is presented to simulate rock failure. Force and displacement are taken as the basic state variables. Based on the basic mechanical laws vector updating rules are constructed, which overcomes the shortcomings of arbitrary decision of local rules and scalar variables. Based on this cellular automata model, rock failure process is simulated under uniaxial tensile conditions. And the influences of heterogeneity and sample shape on uniaxial tensile strength are studied. The results reveal uniaxial tensile behavior of rock and guide the uniaxial tensile experiments.

Using FISH functions written in FLAC, the axial, lateral and volumetric strains as well as the Poisson’s ratio of rock specimen with a material imperfection in plane strain compression were calculated at different elastic moduli. The influence of elastic modulus on failure process and precursor of the specimen was modeled. In elastic stage, the adopted constitutive relation of rock was linear elastic; in strain-softening stage, a composite Mohr-Coulomb criterion with tension cut-off was used; and the post-peak constitutive relation was also linear. If elastic modulus is not very high, only an inclined shear band is formed all along. For very high elastic modulus, finally, the intense shear strain is concentrated into a shear band bisecting the specimen. The numerically predicted shear band’s inclination angles approach Arthur’s and Coulomb’s inclinations and decrease with an increase of elastic modulus, as cannot be explained by the classical theories. With an increase of elastic modulus, the peak stress increases and the pre-peak stress-axial strain curve becomes steep, while the post-peak slope of stress-axial strain curve does not change. The absolute values of axial strain and lateral strain, which correspond to the peak stress, decrease and the post-peak stress-lateral strain curve becomes steep with an increase of elastic modulus. The decrease of elastic modulus leads to greater deviations of lateral strain-axial strain curve, Poisson’s ratio-axial strain curve and volumetric strain-axial strain curve from linear states; higher non-elastic axial strain and higher maximum shear strain increment in the vicinity of material imperfection. Therefore, the precursor to failure is more apparent at lower elastic modulus.

Frost-heave force is one of the main reasons to create disease of supporting structure in frozen soil tunnel; in order to master the distribution shape and the regularity as change as temperature of frost-heave force of Kunlun Mountain Tunnel in permefrast area, in-situ test was carried out. The research results show: by far, the whole supporting structure of Kunlun Mountain Tunnel was safe and reliable; frost-heave force was as change as temperature and season; the change would go to stabilize after 2004, the Max testing frost-heave force was 0.3 MPa, it located in the arch invert between surrounding rock and preliminary bracing; the frost-heave force between preliminary bracing and lining was very small; the supporting strength of lining would consider weaken properly; the frost-heave force envelope curve was plotted by using influence line theory; and it offers a proper and effective method to determine the most disadvantage load which act on the supporting structure.

Method of horizontal push-shear in-situ test is introduced briefly. And calculation formulation is presented according to limiting equilibrium theory. The shear strength parameters internal friction angle? and cohesive strength c of coarse-grained soil compacted subgrade in S325 highway are obtained by three field horizontal push-shear in-situ tests. And its rationality is evaluated. The results provide necessary base for optimum design of retaining walls.

Some cement-soil samples measured in laboratory have showed low resistivity character in a short time after they were mixed. On base of this point, many electrodes were set on the top of cement-soil cut-off wall along it’s extend direction to detect the positions of different defects which had been set in the wall in a short time after it had been built. The measured apparent resistivity sections show depth of wall , blanks between poles and cement to soil ratio variation can bring apparent resistivity patterns change and their positions correspondence. Forward Calculated results with 2.5-D finite element method (FEM) also showed the same resisitivity abnormality character with field detecting results and the abnormal resisitivity patterns changing with the type, size and resistivity variation of defects.

The acoustic velocity may reflect the overall physical property of a rock. Based on triaxiality acoustic velocity test of rocks, the relationship between surface acoustic velocity and acoustic velocity under different confining pressures, i.e. different buried depths, is researched. According to test data and the results of dual parameters’ regression analysis. the rocks’ acoustic properties increased with the confining pressure abiding by multinomial of math. The acoustic properties of different kinds of rocks have different rules with the change of confining pressure; thus, distinguishing lithology profile is one of the basic conditions to research and apply acoustic properties of rocks. Acoustic property of the same rock has larger discrepancies in different buried depths; so, the buried depth is an important factor to research acoustic properties of rocks, which can not be ignored.

Recently, geosynthetic clay liners (GCL) were more and more used in different anti-seepage engineering projects; and their swelling characteristics and hydraulic properties become a focus of designers and researchers. The influencing of liquids on swelling characteristics and hydraulic properties of GCL, as well as the relationship between swelling characteristics and hydraulic properties, were researched through hydration swell tests, free swell tests and hydraulic conductivity tests. It was found that hydration liquid and permeation liquid had influences on swelling characteristics and hydraulic properties of GCL. Test results have shown that: (1) the hydraulic conductivity of GCL was influenced by permeation liquids when hydration liquid was the same; and the hydraulic conductivity of GCL was also influenced by hydration liquids when permeation liquid was the same; (2) there was a relationship between hydration swells and hydraulic conductivities; the bigger the hydration swells, the lower the hydraulic conductivities; (3) there was also a relationship between free swells and hydraulic conductivities, the bigger the free swells, the lower the hydraulic conductivities.

It is a systems engineering to successfully simulate a part of a bifurcated tunnel using 3D geomechanical model tests. It involves how to determine the areas and scale for which the model tests simulate, how to choose the similar material which simulates rock mass correctly in geomechanics model tests, how to design and manufacture the steel structure for the models and the manufacture ,excavation and surveying of the models. This paper indicates all the aspects of the systems engineering based on the internal and external model tests including our model tests. Our model tests show that it can’t be a waste of time. The new type similar material may be suitable for all kinds of models. The steel structure for the models satisfies the necessary rigidity of model tests. The models are easily manufactured and excavated. The results of the surveying satisfy the demands of our tests.

Using test, the engineering characteristics of soil in flooded area by the Yellow River are studied. The constitution characteristics, grain microstructure and physico-mechanical characteristics of the soil are analyzed with x-ray and electronic probe etc. Its compaction mechanics and property is studied too. The soil presents in layer structure, and is mainly made up of silicon and aluminum in chemical constitution. The content of silt is more than 80 %, and its gradation is worse. The grain has high psephicity and severe surface flaking because of the long transport function of water. Consequently it’s difficult to form availably contact between grains, and expressing bad compaction characteristics. When the compaction reaches 90%, the soil has bigger compressibility, because the pore air volume is rather larger. While the compaction rising from 95 % to 98 %, the density and bearing capacity increase obviously. The holding power of low-filling roadbed is inadequate on the condition of overloading seriously, owing to the severe capillarity and high humidity inside the 1.3 m scope above the underground water level.

In order to explain the regularity between engineering properties of soil and geomaterial structure feature, the development process of image analysis method was explored in the research of geomaterial structure. Based on the principles, some characteristics of image processing technologies were analyzed on the macroscopic and microscopic structure of geomaterial. From the macroscopic structure, the mechanics properties of soil were quantitatively analyzed by the displacements of symbol mark embedded in the soil. From the microscopic aspect, the microstructure of soil was also quantitatively analyzed by the technology of scanning electron microscope. In addition, few researchers used the computerized tomography to study the soil microstructure. Finally, a new research method, that is, the combination between a long work distance telecentric microscope lens and charge coupled device(CCD), was proposed to discuss the microstructure of soil under static or dynamic loads.

The basic theories and composition of the elastmeter are introduced, followed by the properties of the marine ooze. The application of GA-elastmeter produced by the French Menard Company to the in-situ measurement of the marine ooze are discussed carefully; then the results are analyzed; the moduli of pressuremeter, deformation and compressibility increase with the hole’s depth to the stabilization step by step; at the same time, preportional limit pressure、ultimate pressure and bearing capacity have the tendency to increase. It is proved that the result of this test can be used to the engineering design and the similar project for reference.

Based on the three-tube parallel shield tunnel that cuts through under Hu-Hang Railway of R413 bid segment of the 9th route of Shanghai track traffic, two groups of centrifugal model tests ,with one group with stratum reinforced and another not, have been done by the method of simulating stratum loss. The longitudinal effect regularity of lining inner force caused by three-tube parallel shield tunnel approaching constructed, has been studiced. The test result shows that the moment of flexion and axial force appear major change at arch lumbus of the left and right tunnel lining when the middle tunnel constructed. The longitudinal effect can be controlled effetely by stratum reinforcement but the influence also should be paid attention to. In the process of construction such method as strengthen slip casting and install longitudinal steel frame can be used for decreasing the influence on the lining duct piece especially on the joint caused by the longitudinal effect.

Through the laboratory experiment, the compaction performance, water stability, CBR of the weathered mica gneiss have been studied. Because of the high elasticity and extremely smooth surface, mica sheets cause the low ability of inlay and anti-cuts. It is easy for the surface layer of the subgrade to peel, loose and to rebound. Then the water stability is bad, the intensity is somewhat low, and the CBR value cannot achieve the intensity standard of the roadbed in the highway. Increasing the work of tamping, the compaction performance of the material cannot be improved obviously. For the construction of the bed, the static pressure is suitable avoiding dynamic pressure. The compaction performance of the material may be obviously improved; and the intensity of the material may be enhanced after improving it with the clay, the weathered soil or the cement. The reasonable admixture dosage of the modified material can be proposed from the engineering economic aspects.

The stabilized dredged silt is used as embankment filling materials, which can not only solve the disposition of silt, but also solve lack of filling materials in the embankment construction. Silt is stabilized by ash-slag cementitious materials (HAS); and some physico-mechanical characters of stabilized silt are measured. Result shows that the liquid limit of silt added 6 % HAS accounts 60 % and organic matter reduce to 2 % after stacked 28 days, and silt is changed into MH from CHO in soil classification. Those mechanical characters such as, the 28 days unconfined compressive strength of stabilized silt reach 1.4 MPa; and cohesion c≥ 100 kPa; friction angles ?＞35°; permeability coefficient is less than 10-6 cm/s; which outclass the standard of embankment filling materials. All those show that it is feasible to use stabilized silt with HAS as embankment filling materials.

Two prediction methods of ground heave in expansive soil foundation based on shrinkage test are introduced; and the comparison research of prediction result is carried out. The analysis indicates that the calculation results of the two prediction methods exist bigger difference for different shrinkage indexes is adopted as calculation parameter. The prediction values of the two methods respectively correspond the lateral unconfined state and complete lateral confined state. Considering the fissure characteristic of expansive soil and the actual lateral confinement state of the foundation, an empirical formula is developed to calculate the ground heave. The suggested method enhances the accuracy of heave prediction of expansive soil foundation, it has significant meaning to the treatment scheme design of expansive soil grounds.

A series of experimental tests for heterogeneous brittle mortar material containing pre-existing internal crack were carried out . The complete stress-strain curves and acoustic emission data of the mortar material in uniaxial compression were obtained using acoustic emission equipment and serve-controlled test machine. Based on these data, the relation of complete stress-strain curves and acoustic emission data were searched .Then the influence of crack angle on the strength of mortar specimens were analysed judging the initiation stress and failure stress of mortar specimens .It is concluded that the strength of mortar specimens is the lowest at α=60oand the highest atα=45o. In addition, the initiation stress on the tips of cracks is about 86.07%-87.42% of the failure strength of the specimens.

Temperature change of the semi-rigid base course is one of the reasons of appearance of the reflective crack. The stress intensity factor of the semi-rigid asphalt pavement is calculated with finite element method. Sensibility analysis is made on the parameters (modulus, thermal expansion coefficient, thickness) affecting the magnitude of the stress intensity factor. Finally, a conclusion that the graded gravel can reduce the reflective cracking, is drawn.

Pressuremeter test has already become a practical, reliable method in geology project appraising, ground bearing capacity measuring through long time application, popularization, development and perfection. Its superiority had also been distinguished itself in the comparision between plate loading test, standard penetration test or other in-situ experiments. Aimed at the puzzles such as loosening, rigid, difficult in sampling and indoor phisico-mechanical testing in hard weathered granite, the high pressure pressuremeter tests are carried out; and some valuable results in engineering are obtained. Results indicate that there are some difference in the correlation of the test between clay and weathered granite because of the differential weathering in horizontal direction in weathered granite; but there also exist some linear relationships between the ground bearing capacity and the measuring point depth, deformation modulus and the bedding coefficient, ground bearing capacity, deformation modulus and bedding coefficient along with the number of standard penetration test. Fitting equations of linear fitting are provided.

Methods of comprehensive control over construction quality of improvement of soft ground for highways engineering are suggested based on a lot of highway projects. The construction quality of improvement of soft ground for highways engineering can be controlled effectively and should be controlled by means of controls of the construction machinery, material, construction arrangement, procedure of production, production efficiency, product examination, rules of quality control, etc..

Probabilistic density of safety factor is basic for calculating slope reliability index and failure probability. Some studies of variability and probabilistic density of parameters, for instance, cohesion, coefficient of friction, unit weight, have been done; these parameters have great influence upon stability of slope; but the present studies of variability and probabilistic density of safety factor have not been done. As an example, safety of Shizibao slope in Badong County of the Three Gorges Reservoir Areas was assessed. In this example, we suppose that parameters c and ? obey normal distribution; the results computed by Monte Carlo simulative method show that safety factor obey normal distribution, probabilistic density of safety factor was quantificationally tested by Q-Q plotting analysis further. Based on normal distribution, average safety factor and risk of Shizibao slope were obtained.

A large rock landslide in the Three Gorges reservoir area involved several complex mechanisms relating to geological, environmental and human engineering activities processes. In response to deformation and failure specificities and trigger mechanism of the landslide, reinforcement measures involving cutting, large section anti-slipping piling, drainage system are used to insure the holistic and local stability of landslide zone. While the validity and applicability of reinforcement sequences of landslides are among the key issues in the whole treatment project. According to analysis of large deformation numerical method and characteristic of landslide treatment project, large deformation numerical methods for analyzing effect of landslide treatment project are proposed. The 3D Fast Lagrangian Analysis of Continua(FLAC) method is adopted to proceeding optimum design of reinforcement schemes, based on analyzing the change of displacement and damaged zone. Treatment effect obtained by all kinds of methods and their combination are compared with each other; and the best treatment scheme involving anti-slipping piling and cutting complementing drainage system is selected as the proposed scheme. The present investigation has provided both factual data and insights for the stability and deformation evaluation of the landslide. The approach and methodology developed are useful for the prevention and treatment of the similar landslides in the Three Gorges reservoir area.

In order to use the characteristic information of different modeling methods sufficiently and improve the quality of prediction result, a nonlinear combining forecasting model for slope stability based on support vector machines with particle swarm optimization was presented. The new model could predict the safety factors using only characteristic parameters of slopes. Characteristic information of different modeling methods were integrated and the chanciness of single prediction method was avoided. In the interest of improving the forecasting accuracy, support vector machines which using a mixed kernel function was used; and the parameters of SVM were selected by PSO algorithm which had the characteristics of parallel and distributing. Applying the nonlinear combined forecasting model to predict safety factors of 10 slope cases after learning with other 73 samples; result showed that the model combining the characteristic information of different modeling methods very well. Compared with single predicting model, regressive combining model and BP network combining model, the PSO-SVM combining model had a higher predicting precision and smallest peak error; thus a new approach to estimate the slope stability more accurately was provided

In the design of the retaining and protecting structures of foundation excavation, the theory of Rankine’s earth pressure is used to calculate the earth pressure on the structure in the present code. The method of these design and calculation is built according to saturated soil mechanics. The results of these methods are not very satisfied. The equations of active earth pressure and passive earth pressure are deduced based on the theory of unsaturated soil mechanics. Finally, taking the actual project for example, the effect of suction and construction time on the earth pressure on the retaining and protecting structures of foundation excavation is studied according to the equations.

Kinematics plays a very important role in the behavior of landslides in discontinuous media. Discontinuous Deformation Analysis (DDA) is applied to simulate the whole movement process of Qianjiangping landslide located in the area of Three Gorges Reservoir. The simulation scheme is mostly based on the characters of geology and landform; and the mesh of elements is based on different types of rock and geological joints. The gradual failure and the movement process after sliding are simulated, all of which are in the working conditions of reservoir impoundment and rainfall. The results of simulation indicate that the local failure in the toe of the slope is the beginning of the Qianjiangping landslide; and it gives a further dragging on the upside sliding body; and finally the landslide is triggered by groundwater pressure.

As an absolutely necessary measure, monitoring on plays an important function during different phases of landslide treating; in virtue of monitoring, the real status, stability and distortion phase of landslide can be got, which will provide immediate basis for laying down primary precautions and schemes to harness landslides; it is real-time information feedback for slope control design optimization, construction informatization and project quality guaranteed during landslide being treated; after treating, the monitoring data is regarded as the direct indicator of treating effect. Combined with engineering monitoring practice during a road cut slope treating, the monitoring systems about different treating phases and the function of the obtained information are introduced.

Based on a field research on the Open-pit Mine and a series of outcrop and lab experiments, the engineering geological conditions such as the lithotype distributing character of rock masses on the northern-side of the mine, and the developing state of faults and joints, are analyzed. Considering that the mine is a slope-type open-pit mine and in consideration of the feature of local crustal stress, a typical section is chosen; and an elastoplastic mechanical model is established; and Drucker-Prager criterion is adopted. According to elastoplastic mechanical model, the influential degree of blasting shock on stability of the high-steep rock slope in mountain area is imitated by using elastoplastic finite elements method, the displacement field and the safety factor of the slope with fault at later stage are computed. Finally, the whole stability of the slope in later period is explored and some useful countermeasures are put forward.

Rainfall is the most important cause of slope failure. The variation in stress state of soils due to rise of groundwater level and seepage of groundwater is critical to the deformation and failure of slopes during and after heavy rainfall. The stability of fill slope depends not only on the strength of fill material but also the drainage condition of the slope. Proper drainage control can not only limit the height of groundwater level, but also dissipate the build-up of excess pore pressure caused by shearing-induced contraction of soil. The possibility of liquefaction and flow failure of fill slope can be reduced consequently. The performance of compacted fill slope during rise of groundwater level is investigated by using a fully coupled procedure and the state-dependent dilatancy sand model. The interaction between pore water and soil skeleton including both buoyancy and seepage effects can be precisely taken into account in a fully coupled effective stress approach. The influence of the drainage condition of compacted fill on the stability of slope is examined. The analytical result indicates that the drainage condition in a compacted fill slope plays an important role in controlling the deformation of slope during and after heavy rainfall. Proper drainage control must be provided in remediation of loose fill slopes.

A new method is put forward to evaluate projects of bracing system for deep excavation to avert uncertainty and random caused by subjective estimation. Weight coefficients of indices are determined by entropy weight method, which combines subjective estimation with objective facts, combines qualitative analysis with quantitative analysis. At the same time, TOPSIS method is associated with entropy weight method to make a rational evaluation. This method has been applied to real project of bracing system for deep excavation; and the result is approvable.

The design idea of slope monitoring information management and assessment system based on GIS is discussed. Measuring data, geological, designing and construction information relating to monitoring works can be stored, analyzed and queried within this system. It also provided some utilities such as graphic visualization, report builder, data modeling and prediction. Based on the Client/Server structure , the need of different levels users is satisfied. With reasonable and flexible structure, database design, the system is avail to the monitoring and assessment of slope projects.

The factors, which control and affect slope stability, are random and uncertain. As artificial neural network can consider both quantitative and qualitative factors, it is suitable to solve the uncertain problems such as the estimation of slope stability. Combining the parallel searching structure of genetic algorithms with the probabilistic jumping property of simulated annealing, a genetic algorithm and simulated annealing algorithm（GASA）hybrid strategy is proposed for the weights learning of BP networks to speed up training process, improve starting solutions robustness and generalization ability and overcome local minimum. With the consideration of the influencing factors of the stability of the slope, a BP neural network model based on GASA algorithm is established for predicting slope stability and a lot of engineering data are collected to train and examine the model. Some valuable results are derived at last.

The simulation of stage excavation of the high slope of Chang-Zhang Expressway is carried out by using two-dimensional elastoplastic finite element method, considering the influence of blasting and rock joint. The rock mass’s deformation, stresses and yielding state in the excavation process are analyzed respectively.The integral safety of the high slope is discussed by using the method of lowing material’s strength safety factor and in light of the yielding rate of the slope’s rock mass element and variation of displacements of the key parts. Through researching the important slope K123, a conclusion that the slopes are stable in construction process, is drawn.

The outlet of the diversion tunnel #2 of Zipingpu Hydraulic Project is located on downriver side of the right bank chine. It is under the trough valley formed by the huge fault zone. It happened several times that the overburden layer of the slope slide during the construction. The safety of people lived near the project was threatened and the construction progress of the whole project was badly affected. Many kinds of methods were synthetically taken to maintain the stability of the slope. FLAC3D is used to simulate the excavation with the prestressed cables and friction piles. The effect of the support is analyzed from displacement field, stress field and other aspects. The results show that the support can remarkably control the deformation of the slope and the slope was stable after reinforce.

The three-dimensional finite element analysis (3D FEA) of support system is carried out with the help of ABAQUS. It is about the internal force and deformation of a typical deep foundation pit during the foundational construction at Tianjin Economical Development Area (TEDA), which is famous for its soft ground. The method of active and inactive element can simulate the excavation progress better; and also solid elements for soil and support system are employed in order to reduce the error produced by degree-of-freedom coupling of different kinds of elements. By comparing the internal force and deformation of the support system of theoretical analysis with the results of field monitoring, it shows that the accuracy of 3D FEA is sufficient for theoretical analysis. The method and conclusions are useful for other similar projects of design and construction of deep foundation pit on soft ground.

Xiangjiapo Landslide is a multilevel and multi time landslide with outstanding characters and complicated engineering geological condition, which came into being by man-made .According to the occurring, expending, evolving and pre-treating process of the landslide, the mechanisms of the landslide under the excavating unloading condition and induced by rainfall later are deeply discussed; and therefore a scientific basis for efficient controlling the landslide is provided.

Gray correlation model can be applied to the sensitive factor analysis of landslide stability; but the traditional approach for computing gray relational grade, which is based on average values, may obliterate information of the specific characteristics of gray coefficients, and possibly make miscalculation of the order relationship with whole approximation. The norm gray relational grade has a better approximation than the traditional approach; and it can express the specific characteristics of gray correlation coefficients. The norm gray relational grade is used to analyze sensitive factors that control the stability of the landslide; and the weight coefficients of each sensitive factor can be calculated. A case study of Tutaizhen landslide in Chongqing Municipality indicate that the shear strength parameters of the sliding surface are the key factors influencing the stability; and the actions of the earthquake and the groundwater are nonessential to the stability of Tutaizhen landslide.

The effects of vegetation transpiration and blocking surface runoff are researched; and three main influences of ecological slope protection on water content of slope rock-soil body and matric suction are put forward. The three aspects of influence are as follows: (1) The action of vegetation’s transpiration consumes the moisture of slope rock-soil body; and it recedes the water content of slope; increases the matric suction and benefits the stability of slope; (2) Vegetation blocks surface runoff and increases the rainfall infiltration, and it makes the water content increased, matric suction receded and disadvantage the stability of slope; (3) How the change of slope body water content and matric suction will benefit the stability of slope because of the existence of vegetation. All these decide by rainfall amount and rainfall type. Therefore, the slope must be made up into waterproof and drainage treatment for the ecological slope protection in area, with flush rainfall and torrential rain.

Influence of excavation on pile foundation stability in a certain engineering of Tianjin Economy Developing Zone was analyzed by using ABAQUS program. Failure cases repeatedly take place in soft clay foundation in Tianjin area. The pile foundation in soft soil often is affected by the side excavation of foundation slot, even lead to the pile foundation to tilt and break. This paper establishes a model to simulate these phenomena by finding out the deformation, stress and the deflection of the pile foundation before and after excavation. The results demonstrate that the excavation can seriously influence the deformation, the rotation and the displacement of the pile foundation, the stability of the whole pile foundation; and combining the mechanical feature, the stability and destroy condition of pile foundation are anatomized. It can be a good example for other engineers.

An improved first-order quadric moment method is used to analyze the stability of slope; and a new calculation method suitable to programming for computer is used to solve reliability index. And then the methods are used to analyze the reliability of stability of Zhaojiapo High Cut Slope in Three Gorges area. The analytical results show that the reliability index and failure probability in the first potential sliding plane can satisfy permissible risk level, that shows, it is stable; the reliability index and failure probability in the second potential sliding plane can not satisfy permissible risk level, thus it should be strengthened; and the stability factor has a good consistence with the results of reliability analysis.

The miscellaneous fill and its feature are described; and arc destroy form is applied for miscellaneous fill slope; and it is proved to be reasonable. Some methods of administering miscellaneous fill slopes were analysed by some case studies. Paying attention to the effect of miscellaneous fill on the side of foundation pit and according to the fact of miscellaneous fill to determine administering plan are emphasized.

Soil arches effect is a hot topic in foundation project. In this paper, we analyzed several the questions which are worth discussed, for example the existence of soil arches and the groundwater to the destruction effect of arches. We proposed the constructive opinion, and anticipated to take a positive role in the development of soil arches theory.

The stability of high rock slope is analyzed with finite difference method. Comparing the difference between original and excavated slope some conclusions are acquired. The destroy mode is round and cut slippage. The slide face is an arc.So arc method is used to calculate the slope stability. The level and vertical displacement is relatively big. The delamination is evident. The maximum and minor principal stress is vertical. And their direction is inclined at the corner of the slope. The minor principal stress of the excavated slope is concentrated. The maximum one is not evident. Some rock area of at the tip and surface of the slope is tension- stress. And some rock slides towards the empty face.

Based on Biot consolidation theory and Terzaghi effective stress principle, a coupling numerical simulation was done to analyze the seepage field characteristics of foundation pit during the dewatering by FEM. Taking the dewatering practice of Jiuhuashan Tunnel foundation pit engineering for example, the shape of phreatic surface, the distribution of seepage velocity and the settlement of ground are analyzed; and the influences of different distribution and depth of draining wells on the seepage field characteristics and ground settlement are compared. This research redounds to understanding mutual action mechanism between groundwater and soils. It provides credible directions to the draining well design for foundation pit engineering.

Based on the limit equilibrium theory and the failure model of grillage supporting structure with prestressed anchor, using Bishop method for slope stability, and considering vertical inter-slice shearing force effects on the shear strength of soil side-slope, the search model of the most dangerous slip surface is set up; ann the solving formula of stability factor is derived; calculation of integral stability of slip surface has been carried out by using the genetic algorithms. The method can avoid getting in local minimum in optimal design; and it has more credible and accurate advantage.

A parallel stochastic FEM based on PC cluster is designed by combining Monte-Carlo stochastic algorithm and domain decomposed finite element method. Making a random field as a sample, exerting the virtues of parallel FEM, huge computing capacity and fast computing, the long time consuming disadvantage of Monte-Carlo method is conquered. Developed parallel computing program using C++ and MPI, then the reliability of a slope is analyzed with 1 000 stochastic samples; and the robust and efficiency of this algorithm are validated.

Combined with a building foundation pit of Nanchang, the retaining and protecting structure of foundation excavation, the horizontal displacement, the settlement monitoring points’ disposal, observation methods and monitoring data processing, are described. Based on the results of monitoring, it would forebode the danger, estimate the safety of engineering and avoid the happening of engineering accident.The construction was supervised with the monitoring results; and the information feedback was optimized designed.There were groundwater inflow and sand inflow due to the abundance of groundwater after the excavation, which made the deeper part such as the elevator shaft pit can’t be excavated to the right location. A method that is forming a waterproof wall around the elevator shaft pit and back covering the bottom of well with jet grouting was brought forward for the limited drainage ability around the excavation. The results show that the elevator shaft pit could be excavated uprightness one day after the construction of jet grouting and there was not water yielding, which brought on favorable reinforced effect and economy benefit.

The bored cast-in-place pile with prestressed anchor is mainly combined to support the excavation, and the medium wells are precipitated to process the groundwater. The dangerous situations as well as the environment influence due to the excavation construction are analyzed with the safe monitoring material. The dangerous situations appeared in the excavation construction are satisfactorily solved by the diligent work of all construction units; the safe operation of the excavation and the environment are ensured.

Referring to the research method of unsaturated seepage and the mathematical model due to atomized rainfall infiltration, using the finite element program ABAQUS, the change of slope’s seepage field and displacement field under the influence of atomized rainfall infiltration is analyzed. The stability of high rock slope due to atomized rainfall infiltration is analyzed, and this method is used in rock slope of a certain hydropower station; the instructional conclusion is gained. Computed results show that slope’s distortion is big because of atomized rainfall infiltration; and the distortion is bigger the infiltration quantity is bigger. So, we should reinforce the protection of slope and try my best to reduce rainfall infiltration and reduce the influence of atomized rainfall infiltration.

It has apparently high risk for bored bottling pile construction in super bridge foundation construction. The full understanding of risk source, the implementation of risk assessment and risk analysis, the prompt prevention and elimination of construction risk have vital significance. As for the Fuchun River great Bridge Project, it was analyzed for contractors that the risk in cross-river bridge foundation construction on complicated geological conditions. From the project management, risk factors were particularly discussed for project cost, progress and quality in over-length bore bottling pile construction. In order to profit construction management, promote project benefit and accelerate the development of risk management, a multilayer fuzzy synthesis evaluation model has been established for the bridge project risk.

Based on careful analysis of variable step size gray predicted method to determine ultimate bearing capacity of single pile and interaction between soil and pile, the problems of the present model to predict ultimate bearing capacity of single pile about derivative of single pile Q-S curve and method to determine background value are pointed out. According to the law of the development on single pile Q–S curve, an improved variable step size gray predicted model to determine ultimate bearing capacity of single pile is put forward. Finally, accuracy standard and reliability of gray predicted method to determine ultimate bearing capacity of single pile are tentatively studied. By computation of the engineering example and comparing with other methods, it is shown that the model proposed is reasonable.

Grout rising along a pile is a general phenomenon in the process of post-grouting. The grout flew upward along the weak layer under pressure, squeezing the soil to a larger diameter and improving the shaft friction. By analyzing the mechanism of post grouting and applying the Bingham constitutive model and flowing equation, the formula to calculate the grout rising height was given. The formula to calculate radial displacement of soils around a pile was given by applying cavity-expanding theory. Compared with the measured results of a project, the calculated values were satisfactory relatively.

Influence mechanisms of loading sequence on pile-soil interaction of negative skin friction (NSF) are simply analysed. Finite element method is used to calculate the differences. Analysis results show that changes of loading sequence would induce the changes of friction distribution in pile, neutral point position and the downdrag caused by NSF. Differences of friction distribution is mainly amount of negative skin friction in upper part of pile, negative skin friction is smaller when negative skin friction appears first; and it does not change with load of pile. Position of neutral point is lower, when negative skin friction appears first; the differences increase as vertical load of pile increase. When negative skin friction appears first, downdrag is smaller than that of pile load applied firstly; the difference increases as load of pile increase. The results will be useful to the research and application for checking negative skin friction.

For the negative force along rigid pile under embankment loads, an elastic differential equation is established. The ground settlement with depth and time is derived from Terzaghi’s consolidation theory; and its distribution is supposed as one mode. The analytic solution for the pile in the homogeneous ground under embankment loads is derived. An engineering example is studied by this method; and all influential factors are discussed respectively.

Influential factors of the ultimate bearing capacity of jacked pile in clay are discussed. The relationship between the ultimate bearing capacity of jacked pile and time is analyzed. Based on the gray system theory, the gray Verhulst prediction model is proposed. Then the ultimate bearing capacity of pile is predicted by the model. The results show that the regularity of predicted ultimate bearing capacity is agreement with the measured ones; and error between predicted and measured value is small. So the gray verhulst prediction model can be applied to the practical engineering.

Analyzing the cooperation mechanism of piles, soil and cushion，the method to calculate the stress ratio of piles to soil is introduced by considering harmony working of piles, soil and cushion in composite foundation. The factors influencing the stress ratio of piles to soil, such as cushion modulus、soil modulus of piles end, rigid ratio of pile and soil, pile length, area displacement ratio, are discussed by calculating stress ratio , and the bearing behavior of rigid pile composite foundation are analyzed.

Based on Mindlin’s displacement solution, through discretization on single pile and surrounding layered soil, a single pile analysis model is developed by considering the relative slipping and the limit shear stress in the slip zone between pile and soil. Thereinto: the settlement of single pile is solved by finite difference method; and the settlement of surrounding soil can be calculated by ML method considering the effect of the soil modulus at all soil layers. The two parts can build relation according to displacement coordination relationship, and used to calculate. This method owns rigid theoretics; and it can feedback the real characteristic of soil mass. Through a case study, it has shown that this method is rational.

The state-of-the art of lateral displacement in soft ground under embankment is reviewed. The problem is investigated using the relationship between the maximum lateral displacement and settlement of embankment center. The calculated model is established with finite element method. The computed results show that during the loading period Δym = ΔS and during the period of consolidation Δym = 0.14ΔS. The loading consequences also affect the ratio. The calculated results is helpful to the research on the lateral displacement.

The interaction between soil and rigid piles loaded laterally is analyzed with finite difference method. There is a little difference between computational and experimental value of bearing capacity of rigid piles. Effects of embedding dimensions of piles and mechanical parameters of soil on lateral bearing capacity of rigid piles are studied. It is found that the lateral bearing capacities of rigid piles have important relation with the elastic modulus of soil, have approximate linear relations with the cohesion of soil and the friction coefficient of pile-soil interface and increase obviously with the internal friction angle of soil. But the effects of dilation angle on the lateral bearing capacities of rigid piles are negligible. The relations of bearing capacities of rough piles with smooth piles and the friction coefficient of pile-soil interface are also obtained.

As a new kind of pipe pile, the cast-in-place concrete thin-wall pipe pile, referred to as PCC pile, with a large diameter, has been used in many engineerings to improve the soft ground; but the bearing capacity under lateral load hasn’t been studied well. Through the in situ test, the authors analyze the horizontal bearing capacity, the pile displacement and the soil pressure around the pile under lateral load. In addition, the effect of the repetitious loading pattern on the pile-soil interaction is also given. All tests show that the PCC pile can be provided with preferable horizontal bearing capacity; and the force act on the PCC pile mainly fast on the upper part; at last, the analysis also shows that the one-way cyclic loading has much effects on pile lateral capacity and the nonlinearity of pile soil interaction.

Artificial neural networks have been used in many areas in geotechnical engineering applications. Adaptive neuro-fuzzy inference system (ANFIS) is used to predict vertical ultimate bearing capacity of single pile. The data of pile load test obtained from a literature are used to train ANFIS network and to determine the network parameters. The results show that the proposed modeling approach outperforms classical back-propagation (BP) neural network in terms of computational speed, forecast errors, efficiency. ANFIS is an effective method to achieve both high accuracy and less computational complexity for predicting vertical ultimate bearing capacity.

A model of 6×6 piles rigid-soft-pile foundation was established to analyze coordinative working performance of composite pile foundation with the three-dimensional FEM. When the ratio of the rigid-soft –pile-number and loading level becomes，the changing rule of loading on the top of the piles and strain-stress in the foundation was researched. If the rigid-soft-piles-number ratio is constant and the piles’ loading is lower than their ultimate loading capacity, under different loading levels, the rigid-soft-pile-loading ratio is nearly invariable. Under the same loading level, there is economical ratio (lower than 40 %) of the rigid-total-piles-number. When the rigid-total-pile-number ratio is lower than it, the stress in superficial layer reduces effectively with the number of rigid piles increased. And the effect of decreased-settlement is also obvious. When the rigid-total-pile-number ratio is higher than it, increased the number of rigid piles reduces the stress and strain in the foundation un-apparently.

The application of squeezed branch piles to the anti floating engineering in the subway stations is introduced. The design theory, construction method, mechanical characteristic and the advantages of the squeezed branch piles in the practice are introduced. It provides the technical basis for the using of the subway station safely. The precious experience is simulated for the subsequent similar underground anti floating design and construction, and it will be valuable reference for professionals in this field.

A new type of casing pipe pile foundation is presented to increase the offshore pile foundation lateral capacity or decrease the lateral displacement. The nonlinear response of the casing pile under lateral load is studied by means of p-y curves. The influence to the pile response of the depth below the seafloor and the width of the casing pipe is investigated and compared with the common pile. The results show that the casing pipe can excite the pile-soil interaction effectively and increase the pile foundation capacity and decrease its response to lateral loads.

Though many tests proved that thin-walled circular pipes will collapse under bending due to local buckling, the bending stability of this kind of pipes in soil hasn’t been studied so far. The behaviors of highway guardrail posts under lateral loads were studied experimentally. It was found that the stability of the thin-walled circular pipe piles under lateral loads depends mainly on the strength of the soil and the characteristic loads on the load-displacement curves all increase with the strength of the soil. Compared with rigid piles loaded laterally, thin-walled circular pipe piles embedded shallowly can be regarded as rigid piles before buckling. Large local deformation occurs only near buckling of pile. The admissible load of pile is linear with the limit cone penetration resistance of CPT representing the strength of soil. Finally, based on cone limit penetration resistance of CPT, a reduced model of soil reaction distribution on pile was proposed; and the soil reaction coefficient in model was back-calculated by the experimental data.

Because of the complexity of influenced factor and the problem of selecting parameters, The bigger difference is consisted in the settlement value calculated and observed, the study on the prediction of settlement has the magnitude significance. The number of prediction problem of inadequacy information is successfully solved by using grey system theory, which is applied widely. The foundation of grey model is based on the equal interval original data. It is difficult to establish prediction model because the equal interval data is not obtained from the practical application. In order to overcome the grey model shortcomings, the grey model is improved. The unequal interval grey model is established and applied to predict the foundation settlement of Yangluo Power Plant chimney in Wuhan. The numerical simulation of the complete process chimney foundation settlement is used by FLAC3D program. The comparison research of the key point displacement by tracking and practical result by monitoring is studied. The result shows that the precision of prediction model is good and can be applied to practice.

The distribution regularity of total additive load induced by bulkhead additive thrust, force of friction between shield and soil, and force of friction between follow-up pipes and soil during pipe jacking construction is studied. The analytical results show that, the distribution regularity of additive load is closely related with the relative position of pile and shield; and it is a three-dimensional problem. Toward the pipe jacking direction and perpendicular to the pipe wall, the additive load is changed from pressure to pull force along with the pass of shield excavation face. In addition, the value and influence bound of additive load in pipe jacking direction is bigger than that of perpendicular to the pipe wall. Value of additive load in vertical direction is small. Direction of additive load close to the axes of pipeline is opposite with that of both ends; and the force distribution curve is arch-shaped. The value of additive load is increased rapidly with decrease of distance between pile foundation and pipeline.

Based on the pull-out test on bolts in-situ, the test data are analyzed and the difference of shear stress distribution along the bolt is discovered between the usual simplified assumption and the actual condition. In usual analysis, the shear stress along the bolt is assumed even distribution, but the real result is negative exponential distribution under pull-out condition. Considering the working mechanism and damage process of cohesion strength, a theoretical model for the pull-out bolt is rebuilt. In this model, the interface shear strength and uncoupling length parameter can be easily deduced from the ultimate load measured from pull-out test. Furthermore, a numerical model including a friction-contact interface element which can simulate the complex mechanical properties of the interface is introduced; and the mechanical response of bolt under pull-out load is analyzed. Comparing the calculation result with the field test, the reliability and precision of the theoretical model and numerical analysis are verified.

Considering the conventional designing method of composite piled foundation only takes the bearing of piles into account. Through studying of the soft soil foundation, a complete designing method has been developed to choose the number of piles on the basis of allowable settlement for the composite piled foundation; that is, to be settlement-controlled composite piled foundation. The paper introduces the basic principles and procedures of the design method taking settlement control as the key objective. Then, the calculation process is presented by a project example; and the numerical calculation is also made by finite element software. Compared with the conventional design method it shows great economic predominance.

Owing to complexity of soil core’s characteristic, the calculation of tubular pile’s bearing capacity isn’t mature. Two kinds of bearing mechanism in clay and in sand are compared. The reason how inner friction appears is that relative displacement or the trend of it exists between the soil core and pile, depending on which the calculation method of the inside friction and of the bearing capacity of soil core top are settled. The conclusion is that the contribution to bearing of inner friction is little in clay and is large in sand for the obstruction effect. At last, predigested calculation formula of vertical bearing capacity of tubular pile is established, Case study are given to validate the method.

In order to study the load-bearing and deformation characteristics of composite foundation with rigid-flexible pile, six static load tests of composite foundation with rigid-flexible piles are carried out under variable parameters, and pressure cells beneath bearing plate are monitored in the process of static load tests. On basis of the test result, the authors analyze systematically the influences of different cushion parameters and replacement ratios, and some meaningful conclusions are obtained.

For the bearing capacity of layered foundations calculated by Meyerhof and Hanna formula, its calculation procedure is refined; and the bearing capacity common model is derivd. The bearing capacity of layered foundation calculated by Meyerhof and Hanna formula is validated by using using the results of in-situ load examination so as to modify the formula. (1) The key step of the formula is to determine the failure plane limit depth, which significantly influenced the result, (2) By the large-scale stress plane in-situ examination, as the layers of soil exceed double, the ultimate bearing capacity of layered foundation calculated by Meyerhof and Hanna formula compared well.

As it has long been recognized that negative skin friction resistance most possibly exists on piles when the soil around pile move downward relative to the pile, especially in collapsible loess in Northwest China. Once it is disposed improperly, the pile foundation will lose its efficacy. So to determine the distribution law of the negative skin friction is of important practical significance in engineering. Concerning the many factors, which always influence the distribution and numerical value of negative skin friction, the field immersion test under static load is still the most effective method in measuring the negative friction. Combined with the experiment of foundation disposal of a power plant in Shanxi Province, the distribution law of negative friction and the influence of collapsible deformation on the bearing capacity of piles are analyzed; and some beneficial results are obtained through these analysis, that will provide instruction for the engineering application.

Using finite difference method, the fluid-mechanical interaction model is established with FLAC for powdery soil subgrade of highway in alluvial plain of the Yellow River. Considering the process of discharge of the pore fluid and layered constructing in the actual roadbed construction, the process of the powdery subgrade deformation is analysed and compared with the result of fieldwork. The results show that, for ordinary section of a highway, the pavement structure can be directly constructed after the roadbed completed if the height of the roadbed ≤10 m; and the allowable subgrade deformation after 6 months of pavement structure completed can not be satisfied if the height of the roadbed ≥12 m. For the head of bridge, the two limits are ≤6 m and ≥8 m of the height of roadbed respectively. For the culvert and channels, they are ≤8 m and ≥10 m respectively.

The settlement and uneven settlement are the key problems subjected to the design theory for tier buildings on deep soft ground. Taking an important project in Wenzhou City as background, the application of the composite foundation of pre-cast tubular pile and mixing cement pile was introduced. Based on the in-site loading test, the major engineering characteristic of this type of composite foundation was studied. Settlement, the stress ratios and load ratios of piles to soil were analyzed carefully. The results show that the stress ratios of tubular piles to cement mix pile and the stress ratios of piles to soil vary little during the load testing, the bearing capacities of soil can exploit quite fully. It will be provided as references for future design and research.

Disturbed by underground mining, composite subgrade in mining subsidence area have large subsidence and horizontal displacement; however, normal bearing capacity calculation approach neglects this influence. Based on the research on the subsidence influence on composite subgrade bearing capacity, an analysis model is established; and a bearing capacity calculation approach of composite subgrade considering the subsidence influence is presented. By an engineering case of ground improvement of a railway bridge in mining subsidence area, if the subsidence influence is considered, the bearing capacity of composite subgrade decreases somewhat.

The mutual anchoring thin retaining wall is a newly-developed structure, which is cheap, convenient and workable not only from a technical but also from an economic point of view. Therefore it can be widely used in civil engineering. On the basis of in-situ test, finite element analysis is conducted to verify each other. Variation rules on the stress of tensile bar, lateral earth pressure and lateral displacement are presented; and that provide theoretical guide for the design and optimization of the new structures.

According to the rock characteristic and coal seam occurrence condition of 3208 material tunnel roof at Daxing Coal Mine, combining with modern theory of coal tunnel support technology, the combined support parameters of bolt, anchor cable, steel strap and mesh for the tunnel, are put forward; and daily tunnel pressure and support observation, such as roof separation, tunnel convergence deformation, anchorage stress of bolt (anchor cable) etc. have been done at a long time. The results of try-on and observation indicate that the application of bolt, anchor cable, steel strap and mesh combined support technique at Daxing Cola Mine soft-roof tunnel is successful and feasible. Suggestions about the support way of tunnel in samdwich and joint and cracked fake top are also presented.

The retaining wall commonly existing in slope engineering, the effects of matric suction and retaining wall are important in the design and safety evaluation of the reinforced slopes. In order to decrease the occurrence of failure it is essential to properly evaluate the global stability of unsaturated soil slope reinforced with retaining wall. By using the strength reduction finite element program to implement considering matric suction, the global stability of reinforced slope is analyzed; and the computational results reveal the contribution of matric suction and indicate the variation trend of global potential sliding surface. Sensitivity analysis of suction friction angle is also presented.

Coal refuse, a kind of special softening coarse grained soil, has amounted to 7 billion tons throughout China; and with l50 million tons being produced annually. Not only plenty of lands are occupied, but also colliery wastes pollute the natural environments. The paper focuses on the use of coal refuses, concerning the feasibility of coal refuses as a road base materials. Coal refuse mixtures are tested with 10 different lime and fly-ash contents and different aggregate gradation. Unconfined Compressive strength modulus of resilience and temperature shrinkage coefficient are tested and analyzed. Mixture ratio is recommended by the research. Proper ratio of lime to fly-ash is 1:2, percentage of lime and fly-ash is 30 %. Preliminary results indicate that coal refuse can be used as a sub-base material of high-class road or base material of low-class road.

Usually, because the soil nail is slender, it offers little bending resistance, finite element method and finite difference method regarding the soil nail as a one dimensional structural element with the capacity to sustain uniaxial tension and compression. In fact, the shear force of the soil nails take very important role in control the displacement and maintain the stability of the slope. The authors proposed a new method to calculate the shear force of the soil nail. An example of foundation pit is illustrated; the results of the soil nail take the shear force into account consistent with the measured in-situ very well. Conclusions may be of very practical value in design and construction of soil nailing.

The traditional new Austrian tunneling method (NATM) is introduced. From the NATM we know that maintaining the stability of surrounding rockmass must fully utilize and mobilize the strength of surrounding rockmass and its carrying capacity, and depend on co-action mechanism of the surrounding rockmass and support. We study the mechanism of bolt-netting, and setup the mechanic model of high strength and prestressed bolt. We find that the anchor strength of high strength and stressed bolt is related to property of surrounding rockmass, the anchor mode, staff of bolt and the stress of surrounding rockmass, etc. Meanwhile we analyse the co-action mechanism of bolt-netting support and surrounding rockmass, and apply FLAC to study the mechanism of bolt-netting support, and find that the bolt-netting support and surrounding rockmass come into the compressing arch. The roadway depends on the compressing arch resisting the surrounding stress, and maintains the stability of the surrounding rockmass. The deformation and destruction of surrounding rockmass is very serious. By scene test at 41 connecting roadway in the Xiaoguanzhuang Iron Mine, the deformation of roadway is small; the bolt-neting support can maintain the stability of high-stress and fragmented rockmass. The bolt-netting support has the extending and applying value at the similar metal mines.

Based on probe to the difficulty in the full-scale test-in-situ of the anchor cable, then the stress and displacement of the prestressed anchor body, the distribution principle of the shear stress on anchor body face, which is influenced by the different anchor cable rigidities, the elastic modulus of rock-soil body and the scale of prestressing; and the diversion trend of the plastic damage zone are numerically simulated by use of FLAC3D. The distribution formula of shear stress which has the r index function relationship is fitted. Under the deduction that the peak value of the shear stress continuously expands to the tail of the anchor body, the paper puts forward the formula for ultimate anchor force on the interface of the grouting body and rock-soil; it has academic and practical significance.

Model research on distribution regularity of shear stress on anchorage end of prestressed cable is carried out according to half space with concentrated force in normal direction on boundary based on the elastic theory. By analyzing the distribution characteristics of shear stress in practical engineering and field experiment, the distribution regularity of shear stress on anchorage end can be modeled with the introduction to parameter ? which is correlated to prestress, length of anchorage end, rock strength, and cementation strength and parameter ? which is correlated to the position of peak shear stress and the diameter of anchorage end. Ultimate bearing capacity can be calculated according to compression strength ?c and internal friction angle ? of cementation material and the approximately linear inverse proportion relation. Meanwhile, the design length of anchorage Ld multiplied by 2tan? makes the practical length of anchorage end Ls which is calculated by the paper’s method. Finally, two cases calculation and analysis show that the research production is reasonable.

cantilever retaining structure caused the large lateral deformation in soft soil region. Improvement of soil is an effective measure to decrease the lateral deformation. Based on elastic foundation beam theory, a finite element model of foundation pit is founded. The effects of soil improvement on lateral deformation and inner force of cantilever retaining structure are studied. The results show that the lateral deformation reduces with the deceases of depth and degree of improvement of soil. There are critical depth and degree in improvement of soil. The change of inner force caused by depth and degree of improvement is small. To save the engineering cost and guarantee the pit safety, it is important to reasonably decide the depth and degree of improvement of soil.

The shear stress distribution of the wholly grouted bolt is analyzed by using a nonlinear finite element method; also the strengthened rock-soil body's properties are researched, which influence the anchorage body's shear stress distribution. Afterwards, a contrastive analysis is done among numerical simulation result, theoretical calculation and experimental result; it indicates that the shear stress distribution in the anchorage body is uneven. Under the small load, the bolt's shear stress distribution range is small but the maximum shear stress is large; with the increase of load, its distribution range tends to expand downwards with a slow speed. The shear stress and its distribution have a close relationship to rock-soil body's properties: the stiffer the rock, the more concentrated the shear stress and the larger the maximum shear stress; on the contrary, the evener the distribution and the smaller the maximum shear stress.

According to the stability analysis of one shallow-buried air-raid shelter of which buried-depth is about 6m to 13 m, a grouting strengthening method for the air-raid shelter is proposed. During the construction, the mixture ratio experiments of two kinds of mortars are made. According to the mixture ratio, it is determined the strengthening materials and their mixture ratio of seepage area and no-seepage area; and according to the real construction, it is determined the grouting process, the spread-radius of the mortars and three kinds terminating-plan of the grouting. It can be concluded that this strengthening measures attain the expecting effects and purposes, according to the testing effect of the spread-radius of the mortars and the compressive strength of drill cores.

The vacuum preloading method has been largely developed at home and abroad in recent years; as a new mean of treating soft clay. Many research works have been done about laboratory experiment, field test, mechanism and numerical method of vacuum preloading. The situation of research about the vacuum preloading method is analyzed. And it is expected that the analysis can be contributed to the development of the method.

Based on the Kelvin formula of elastic space solid bearing the concentrating force interiority, the theoretical solutions of the extra-stresses and displacement distribution of the pull-type cable anchorage segment are derived. Subsequently, the distributing formula of shearing stress around the anchorage segment is obtained. Therefore, the influences of mechanical characteristics of the anchorage segment and the rock mass on the extra-stresses, displacements and shearing stresses are discussed. The results show that the field of the normal stresses and displacements around the anchorage segment are tapered. The stresses up the origin of the anchorage segment are compression ones, and those below the origin are tension ones. They are decrease very fast from the origin. The shearing stresses around the anchorage segment form a taper surface and decrease very fast.

The conventional methods for designing of anti-slide piles are based on constant value; it isn’t consider the randomness and variability of the parameters, so the design of anti-slide piles will lead to some limitations: one is the methods can not give the safety of the slope; the second is the relatively conservative designing will lead to waste. But the reliability analysis method that consider the randomness of the parameters can measure the safety by rigidity probability, so that it also can make up difference that lie in the tradition anti-slides piles. Considering the reliability method, basing on computing formula of traditional slope stability, the evaluation model of slope stability is built. Using the M-C method and the single parameter sensitivity analysis method, the parameters in the design of anti-slide piles on safety factor and the reliability index are presented. It is demonstrated that the reliability index is affected obviously by the shear strength parameters, the gravity of rock and soil, the diameter of anti-slides piles, and the safety factors of slope sensibility is higher in some parameters such as rock and soil gravity, pile effective length, and pile diameter etc.

The design of reinforced high rock slope is made by analyzing its stability. The detailed programme is to utilize combined anchor and concrete. And the design is proved to be efficient with finite difference method. The finite difference model of the reinforced slope is created. The slide face disappears after reinforcing; and the stability coefficient meets the safe rule. The whole slope is stable. The method and conclusion are efficient to actual slope engineering and design.

The variations of groundwater table and water flux are analyzed and studied in soft soil with confined water stratum by vacuum-surcharge preloading. The field test results indicate: (1) technology of ‘tearing membrane’ and ‘non-tearing membrane’ could effectively prevent the connectivity of confined water; (2) groundwater table at later stage is quite stable and the maximum dropping is 1.8 meter, SW2 arises about 1.0m, which indicates this area is partially penetrated by confined water; (3) confined water table at inward and outward is quite similar, they are separately influenced by degree of vacuum and rainfall; (4) water flux is very large at early stage, which diminishes sharply with time, and water flux of single vacuum pump is less than the one at the same zone by the same method, which indicates soft soil never completely connect the confined water stratum by vacuum-surcharge preloading.

The pressure-dispersion –type prestressed anchor cable is increasingly used in complex high slope stabilization projects due to its many advantages. The key to reach an ideal result in construction is to scientifically choose the proper constructing techniques according to the character of high slope rock mass and working conditions of the facilities. Taking the 17th signing sector of the Jin-Li-Wen expressway for example, a detailed description of the construction techniques of pressure dispersion-type prestressed anchor cable is made in terms of organizing of the project, field-test, drilling, mortar injection, straining and tensioning, monitoring etc.; thus some referencing experience is given for the similar projects.

The principle of the dynamic consolidation method(DCM)for reinforcing soft foundations is analyzed; pore water pressure through the whole working course is monitored; the curves of SCPT before and after tapering is given; the settlement curves of consolidation area to unconsolidated area and the result of loading test are shown.

In engineering, packaged geogrid reinforced soil retaining wall’s design still use anchorage wedge method based on limiting equilibrium theory that doesn’t consider the progress of retaining wall’s deformation occurrence and accumulation before reach limitation. Retaining wall’s horizontal displacement is an important appearance of its stability. By using FEM, the effect aroused by different engineering factors is analyzed. The analytical results show: results of FEM fit well with in-situ test and it proves the FEM results are reasonable; reinforced soil retaining wall’s post-construction horizontal displacement enlarged from bottom to top; geogrid’s stiffness, length and vertical span have apparent effect for horizontal displacement, and should choose suitable design value to get desirable engineering behavior; the magnitude and location of outer load above retaining wall have corresponding effect for horizontal displacement that effect becomes unapparent when the outer load located besides the reinforced zone.

Based on mechanical properties of the special soil layers in Yellow River Delta, with the horizontal acceleration time path of Tianjin seismic wave taken as the input seismic wave, numerical analysis is carried out on seismic response of the soil layers in the depth range of 20 m in Yellow River Delta. Three transcendental probabilities, i.e. 3 percent, 10 percent and 63 percent, are considered to study changes of pore water pressure and dynamic shear stress, which are compared with those obtained in laboratory dynamic triaxial tests to evaluate liquefaction potential of the soil layers. Research results show that under the transcendental probability of 3 percent, most of the soil layers will fail; under 10 percent, only a few will; and under 63 percent, most will not. Evaluation results obtained with failure dynamic shear stress ratio coincide with those obtained with pore water pressure ratio.

Seismic liquefaction of deep-sand lens in a dam foundation is evaluated by two processes. Firstly, specification methods are used to make preliminary and again judgment. Secondly, Seed and Dobry methods are used with dynamic triaxial test results to make more evaluation. Various estimation methods are analyzed synthetically. Based on the analysis results and considering the practical engineering conditions, a conclusion that a special treatment is needn’t made for deep-sand lens in dam foundations, is drawn.

High-enrockment embankment chronically received the effect of dynamical load in the run course after the construction. Based on the resemble scale theory, a dynamical response indoor model of high-enrockment embankment are used to simulate the syntony load and impact load is established. The factual complicated dynamical load of high-enrockment embankment received. Using dynamic earth-manometer and accelerometer to pick up response wave; Using Drucker-Prager elastoplastic model to analyze dynamical response finite element on high-enrockment embankment. It was shown that the finite element analytical result was in good agreement with experimental data; even under the bigger dynamical load, plastic area in high-enrockment embankment was also just temporary and partial; it still could maintain whole stability, and expressed a dynamical strain hardening characteristic.

A dynamic response problem about thick-thin plate on tension -free double parameter foundation with random moving loads and problem about plate untouched foundation have been solved. From the generalized potential energy functional analysis of subsea of system about plate-foundation touching beginning, we can get subsea generalized harmonious element about solving dynamic response problem of plate on tension-free double parameter foundation with random moving loads through building and analyzing potential energy functional analysis of section about plate element, section of foundation element and section of plate-foundation element. We use method of Newmark and programme with MATLAB through iterativeness and get dynamic response value of every point in midst plane about moving loads in different instantaneous, different place. We also get the region and area of plate untouched foundation. Through numerical calculation, we can verify the method proposed, with which analyzing dynamic response problem about thick-thin plate on tension-free double parameter foundation , is effective.

The damage of buried pipeline is controlled by site condition, such as faults, characteristics of rock and soil. Analyzing the influence of site condition on the damage of buried pipeline under earthquake load is the key of earthquake lifeline engineering. By the operation of defintion body in ADINA, the type of site body is selected, and pipeline body is subtracted from site body by Boolean Body Operators. Therefore, the geometry model is obtained. Through model preferences, parameters of the model are defined, such as the characteristics of rock and soil in site, characteristics of pipeline and faults. Time function of earthquake load and displacement load of faults are applied, initial displacements are defined based on the movement of faults, and pipe-soil friction is considered by contact control in ADINA. According to the calculating results, influence of buried depth, parameters of faults, pipe-soil friction, and faults movement is investigated. Some advice for the protection of buried pipeline under earthquake load is proposed.

The influence on microshock liquefaction by different permeable boundaries of soil is variant. Combinations of permeable layer and confining stratum are used in the paper. Filed in situ cyclic loading test and indoor vibration testing of soil samples are made. The analysis of test phenomena and variation of density, water content and void ratio of soil sample in cyclic loading test is made to study the influence on soil liquefaction by combinations of permeable layer and confining stratum and different direction of vibration force. The soil is belonged to marine deposit of Yellow River delta.

Component object model GIS (COMGIS) technique is adopted to develop the hazard evaluation system for earthquake-induced site liquefaction potential combined with BP model of artificial neural network (ANN). Firstly, the simulation of site earthquake influence field under scenario earthquake can be generated by calling SHAKE91, a commercial program to analyze seismic response of level layered site. Then, seismic hazard for sandy soil liquefaction can be evaluated by BP model of ANN which is modularized under VB by importing ANN toolbox from Matlab. Thus the analytical results from BP model of ANN can be simulated spatially by GIS; and the spatial distribution of site liquefaction potential also can be graphed. The research shows that: First, SHAKE91 software can be called directly from the system menu to simulate the site earthquake influence field. Second, the relatively perfect results can be obtained when the BP model of ANN is utilized to predict the latent hazard of earthquake-induced site liquefaction. Third, by GIS technique, the evaluated results can be perfectly matched with the site information spatially. Thus the critical site liquefaction hazard area can also be identified.

The reinforced concrete frame building with complicated surroundings was demolished by blasting. The bearing posts of building have multi-sections. The blasting parameters and specific charge for posts with different sections were determined through trial blasts. The non-load-bearing structure which may affect collapse of building were shut off in advance on the basis of safe construction. Some blastholes were arranged on primary and secondary beams, stairs and connections of beams and posts on blasting floors. These holes exploded with blasting floor, therefore, the structures could be break up adequately in course of building demolition. The cross duplicate non-electricity network was designed; and water spray automobile was used to eliminate dust in building blasting. The favorable effects were achieved in practice.

Model tests on composite foundation of cement-soil pile under cyclic loading were conducted. The vertical additional pressure, stress ratio of pile and soil, the pore water pressure, and the settlement of composite foundation of cement-soil pile, etc. were discussed. The test results show that (1) the saturated soft foundation improved with cement-soil piles occurred redistribution of stresses; (2) the effects of cyclic stress ratio, number of loading cycle and replacement ratio on the stress ratio of pile to soil of composite foundation were remarkable; (3) the saturated soft foundation improved with cement-soil piles decreased the pore water pressure value and the settlement of back work; (4) the vertical deformation of the top of piles and pile-surrounding soil is not coordinative. The permanent settlement of the pile top piles is less than that of pile-surrounding soil; and this tendency is more remarkable with increasing number of loading cycle.

The methods of taking half or 2/3 of shear response spectrum as vertical seismic action, recommended or prescribed compulsorily in many engineering codes at home and abroad, are used to design buildings. But how to rationally consider this effect is one of the most important tasks. Firstly, these research advancements are reviewed. The necessary of equivalent linear method of 2D wave motion explicit FEM ELPSV program with characteristic of high efficiency, real phase, actual radiation damping, is discussed. Then, strength of vertical strong ground motion influencing on response spectrum of slope site surface, equivalent response history and PGD and PGV in site section, seismic response of soft slope site are analyzed; and draw some primary conclusions as follows: There are certain influences on shear seismic response spectrum when the period less than 0.3 s, but it is very light over 0.3 s. Vertical seismic response of slope site was distinctly changed by vertical strong ground motion. Moreover, value of vertical seismic action in code for seismic design for buildings is apt to unsafety. Simultaneously, vertical response of the right site is great than the left’s. The slope top’s shear response is much stronger than slope feet’s for slope topography condition, while vertical seismic response is not obvious. Magnified effect in strong ground motion is more than in weak motion when ratio of horizontal to vertical component(av/ah) is 2/3, which agrees with the knowledge of nonlinear response. Interestingly, Interface effects make the response is lower than ambient site response. And soft site response is essentially consistent with phenomena of the hard site, except for vertical seismic response is increased previously and then decreased from site bottom to the top. At last, concise epilogue is given. All of conclusions and study results reflected quantitatively effect extent of vertical strong ground motion, provide beneficial basement for rational considering vertical strong ground motion in aseismic design of buildings and constructions in slope site.

Sloping soil layer will be liquefied and yield large deformation under earthquake vibration. Based on finite element theory, a numerical method is studied for seismic liquefaction induced large deformation of gentle inclined soil layer. In this method, Liquefaction analysis is performed by two-dimensional dynamic effective stress finite element method, and in each time segment of the analysis, modulus of soil elements are achieved considering soil liquefaction and vibrated soften; then large deformation of soil layer is calculated by nonlinear static method in the end of each time segment, horizontal and vertical displacements are acquired in any depth of soil layer at last. By examples, the influences on large deformation are studied with different earthquake accelerations and slope angle. Compared with the results of other researches, the validity of the new method is confirmed; and it is applicable to solutions of earthquake geological hazards evaluating in engineering field.

The mechanical model of rockburst in 296 π coal face up roadway is built based on geological conditions and in-site investigation; influence factors and their reactive regularities are anslysed. Rockburst mechanism and reality condition are discussed. Pressing and feasible preventive measureres are referred for rockburst in Junde Mine 296 π coal face.

Based on bedrock digging of embankment project in the Three Gorges Proiject, the choice of measurement method and object of vibration by blasting earthquake wave induced by bedrock digging of embankment project were studied. Via regression analysis of the results of measurement on blasting vibration, the spread and attenuation regularity of vibration velocity of blasting were established. Combined the project, the vibration frequency of earthquake wave induced by blasting of bedrock digging and the vibration frequencies of surrounding buildings in blasting zone were contrasted and analyzed. After analyzing, the vibration frequency by blasting of this digging project was far bigger than the itself vibration frequency of structure of surrounding civilian house; consequently the safety of surrounding buildings were assured. At the same time, integrated the digging blasting construction of embankment project, the safety control standard of blasting vibration by this blasting engineering was confirmed from the two aspects such as safety vibration velocity of buildings and safety distance of blasting vibration; consequently, it is shown that the construction task of this blasting project were done safely; and the safety of surrounding buildings were assured while blasting was on. This research has played an important role in coaching blasting construction of bedrock digging and assuring the safety of ground buildings.

The experiments of cyclic loading and unloading, uniaxial and triaxial stiffness of rock and the numerical modeling analysis of deep rock mass are completed in Linglong gold mine. Based on the results the experiments and numerical modeling, the phenomena of higher elastic strain energy and the distribution of rather large elastic energy resilience in deep rock mass are analyzed in general. The releasing of the elastic energy resilience has high impact characteristic. The great possibility of rock burst during deep mining excavation in Linglong gold mine are concluded by using various prediction criteria of rock burst. The conclusion is that the rock burst can be forecasted. The methods and the safety precautions against rock burst are also proposed according to the actual construction.

According to the characteristic of Liaocheng-Tai’an natural gas duct excavation engineering of West-East natural gas transmission project, the suitable pattern of hole disposal, the blasting parameters, the structure of stage charge, the reasonable firing method and the detonation sequence of the blasting excavation are discussed. The principle of ditching blasting and the scheme of blasting construction are summarized based on the above analysis. The techniques of millisecond blasting and safety measures of reducing vibration and controlling blasting f1ying rock are put forward. So the security of communications cables and the surrounding facilities are guaranteed; and ideal achievement is obtained. Favorable conditions are created for the smooth progress of West-East natural gas transmission project.

Under different load patterns, some experiments using special mortar specimen are carried out. The whole process of initiation, cracking, growth and fracture of cracks is analyzed by using acoustic emission (AE) technique. Experimental results show that the AE properties of tensile fractures are different under loading types. The AE properties of crack propagation process under bending action contain four stages: gradual increase, quick increase, sudden increase and gradual decrease of AE numbers. But those under splitting load, it contains three stages: slow increase, sudden increase and stable increase of AE numbers. The AE characters of crack initiation and coalescences under bending are obvious, but not clear under splitting load. It deserved to further study the AE properties under different loading conditions.

Based on the engineering of double circular shield tunnel of Shanghai metro Yangpu Line(M8) between the railway stations of Huangxinlvdi and Xiangyin Road, research the law of dynamic response of double circular shield runnel in soft soil under vibration loads caused by the train. After the modal analysis of the system of metro shield tunnel and stratum, its vibration pattern and frequency can be obtained; so the rational time step and damping of vibration analysis are defined by vibration modes and frequencies obtained with modal analysis. Adopting the modal of vehicle-tramroad, the vibration loads caused by the train are calculated; then the initial in-situ stresses is defined, with the transient analysis, under the two kinds of vibration loads of single train and two trains, the random dynamic response of the double circular tunnel subway in soft soil can be obtained, and its weak parts and their displacement field and stress field are obtained; so when designing the two-circle shield tunnel in soft soil, the loads caused by the vibration of trains should be considered.

A simplified procedure for evaluating aseismic stability of slope subjected to earthquake shaking, in which the effect of dynamic shear strength and time-history stress on the yielding angular acceleration of sliding block is taken into account, is presented. The fundamental feature of this procedure is the dynamic shear strength. The numerical computations are performed by using the proposed method. It is shown that the computed sliding displacement for a given core dam, with either method of dynamic shear strength properly considered, is more rational compared with the conventional computational results based on static shear strength.

Rigid and brittle rocks trend to rockburst，which is generalized by uniaxial compressive strength ? c, ratio of compressive strength and tensile strength ? c /? t and exponential of strike energy WB. Before physical model is made, some similar materials, such as quartz sand, gypsum, cement, water, glycerin and glutin, are blended by different proportions of ingredients according to the principle of orthogonal test design. In course of the proportioning, the small model samples are produced and uniaxial compressive test and split test are done with them. From the results of the tests, it is found that the different proportions of similar materials influence ? c , ? c /? t and WB differently. Based on physical simulation, ? c , ? c /? t and WB are checked in general and the directions for the material generalization are confirmed. The mechanical parameters of materials by the directions, which are steady, not only meet with requests for rockburst, but are convenient for making big model. Therefore, great physical simulation for rockburst is feasible.

The achievement of this research is the fundamentals of a 3-D dynamic consolidation with governing equation established on the basis of transient dynamics theory ,characterized by drawing into it the effective stress and physical states dynamic constitutive relation and coupling the dynamic response and dynamic consolidation, static stress and dynamic stress, pore water pressure generation, pore water pressure diffusion, dissipation with each other so that to simulation the true process of stress-strain response of soil mass and to form a complete theoretical framework system of the seismic response analysis approach based on effective stress and physical states of soil mass. This method can reflect the shear dilatation-contraction real behaviors of saturated soil road foundation under earthquake; and it is more reasonable than usual static-dynamic alternate analysis method by finite element method.

Rock is regarded as particles with internal friction. The process of rock failure under impact loading is analyzed with mechanical model; and the dynamic behavior is described. The deformation near impact loading in rock is similar to one-dimensional deformation. The stress wave form the loading can be regarded as short-wave whose characteristics have sharp varieties in a cabined zone near wave front. The stress state will transfer from elastic state to internal friction state; finally liquid hydrodynamics state, with strong or leak movement of particles.

Analysis of response of level ground subjected to earthquake is one of the most important problem in geotechnical engineering practice, which could be very complicated especially when saturated sand is involved, as material nonlinearity and soil-water interaction should be taken into account. A fully coupled simulation of seismic ground response at centrifuge was performed, by use of the finite element procedure SUMDES, incorporating a unified constitutive model for granular material. The analysis results show that the ability of fully coupled code to reproduce the whole picture observed in the test, including generation and dissipation of excess pore pressure and deformation of soil body. The importance of calibration of model parameters and determination of the corresponding coefficients, especially the coefficient of permeability is also demonstrated.

The Jinping Hydropower Station is a national important large-scale project. The tunnel of the project is very long and has a big diameter; and it is buried very deep. Its wall rocks are very complex in tectonic geology; and the faulted structure is very developed, especially this area is a high ground stress area. The process of excavation is the process of unloading for wall rocks. Through analyzing the confining pressure unloading experiments on marble with constant axial load, we discuss the relationships between elastic modulus, Poisson’s ratio, axial strain and confining pressure; and a conclusion that the axial strain of marble is nonlinear when confining pressure was unloading, is drawn.

Combining the practical situation of Neijiang to Kunming Railway Yanjin Tunnel #1 under through the buildings, by the means of trial blasting and vibrancy monitoring, blasting methods which should be used was researched for the railway tunnel under through the buildings closely. The result shows that they the blasting parameters which gained by blasting design in site are reasonable; propitious to the buildings of closely tunnel construction successful; during the construction of closely underground engineering, before the major and difficult construction, blasting test and vibration vibrancy monitoring were the effective methods to ensure the construction successful to build; the disturbance damping blasting technique has wide utilization space; with the development of blasting technique and blasting equipments, it would display imponderable effects in controlled blasting in future.

In order to analyze characteristics of stresses in ground induced by train, train-induced reaction force between ground surface and embankment was calculated based on Euler-Bernoulli beam on elastic foundation under moving loads. Exerting the reaction force on the ground surface, the corresponding steady-state stresses in ground were obtained by integrating the basic solution of a moving point load on an elastic half-space surface. The results are valid only for train speed lower than Rayleigh wave velocity in ground. The variation of stresses with spatial coordinates and time was presented. Characteristics and distribution rules of stresses were studied. It is found that the dynamic stresses seem to be a kind of particular cyclic load with deviatoric stress. With train speed increasing, the effective range of vertical stresses increases continuously.

This paper presents a procedure for calculating the safety factor for an unsaturated and anisotropic slope suffering from rainfall infiltration. The process of infiltration into a slope due to rainfall and its effect on soil slope behavior were examined using a one-dimensional finite element flow deformation coupled analysis program. The modified Mohr-Coulomb failure criterion was adopted for unsaturated soil strength considering variations in strength due to the presence of matric suction. A safety factor was calculated based on the smoothed stress field obtained from finite element analysis; and an optimization technique was used to search for a critical slip surface. Some numerical examples are analyzed. The results illustrate a typical process of infiltration into unsaturated soil slopes and the effect of hydraulic conductivity on slope stability during reinfall-induced infiltration. And the analytical data indicate that the existence of the cranny has a distinct effect on anisotropic slope stability. The effect of cranny should be considered in analyzing stability of slope infiltrating by rainfall.

Through conventional triaxial test and equal stress-ratio pressure test of intact loess sample, base on the result of the stress-strain characteristics curve analysis, the yield function of the model is directly determined from experimental data. According to the Drucker’s postulation, the elastoplastic model of unsaturated loess is proposed by selecting proper hardening parameter, and carried on the comparison analysis of the test result and the model computed result. The results show that the model can simulate the softening phenomenon which is related with the consolidated stress; and the results of the calculation coincide with the results of tests.

Based on 3-D FEM for the culvert under dam on the soft foundation, the earth pressure and settlement of the culvert are analysed. It is found that as follows: (1)When the reducing load measure is applied, the earth pressure distribution around the culvert and non-uniform settlement of bottom of the culvert are the same as without reducing load measure, but the vertical earth pressure reduce greatly which shows the effect of reducing load is obvious. (2) The variation of depth of the ground treatment has effect on stress around the culvert. The vertical earth pressure on the top of culvert slowly increases and the horizontal earth pressure at the side of culvert slowly reduces with the increase of depth of the ground treatment. (3)Although the settlement of the bottom of the culvert slowly decreases with increase of depth of the ground treatment, but the non-uniform settlement ratios are less than 0.5% which affecting the culvert are the same as each other. No treating the ground of the culvert, the danger is not produced with a few increase of the non-uniform settlement.

In order to analyze the anchors supporting structure’s effects, the 1+016-1+080 navigation route bank high rock slope in Longtan Hydropower Station were respectively computed under the supported and un-supported conditions by two-dimensional plane elastoplastic distinct element method(DEM). In the computation, the stress field, deformation field, plastic yielded zones distribution and stability were respectively calculated under supported and un-supported conditions. At the same time, the anchors axial forces during the excavation steps and the groundwater level effects on the slope deformation are also calculated. The analytical results show that there are obvious differences between the supported and un-supported conditions; and the anchors supporting structure can diminish slope deformation and improve the slope stability. Meanwhile, the ground water level of the slope has the obvious effects on the slope’s deformation and stability. The slope top deformation and the anchors’ inner force are measured during the excavation step and there was a good agreement between the DEM computation values and the surveyed values; for example, the max calculated slope top deformation is 9.48cm while the measured values is 7.55cm; and it is shown that the 2D elastoplastic distinct element method is suitable to calculate the high rock slope problems.

In forecasting deformation of dam, many influential factors exist as well as interrelation of factors was complex. Hence, general simulation functions are difficultly to meet the needs of safety supervising of dam. As we know, adaptive neural-fuzzy inference system(ANFIS) has good capability of fuzzy system and artificial neural network. Influential factors of deformation of diaphragm wall analyzed systemically as well as effects of temperature, time, and water level of reservoir considered, predicting model of deformation of dam is established based on ANFIS. Taking the second stage cofferdam of Three Gorges Project for example, the studies are carried out with this model. The results show that the model is simple in calculation and good in applicability and precision, so as to provide a new method for forecasting deformation of dam.

The natural element method (NEM) is a newly coming meshless method, of which the shape function possesses both the characteristics of the meshless methods and the advantages of traditional finite element method, so it’s a most promising numerical method for geotechnical problems. The basic theory and the characteristics of NEM are addressed; and then some detailed application examples in geotechnical engineering are discussed. The Goodman element is introduced into the NEM to model the discontinuity; the general principle and detailed implementation are identical to those in FEM. How to model the infinite or semi-infinite problems using NEM, is discussed too. The coupling of NEM and FEM or IEM is seamless, because the NEM shape function satisfies the property of linear interpolation between adjacent boundary nodes. So the solving ability is enhanced by the coupling. Numerical examples show the rationality of scheme presented above.

Use stabilizing piles for landslide control is a common measure. The space between piles is a very important parameter. Engineers must find a balance between landslide control ability and cost. In China, at the present time in engineering practice and based on empirical formula, the pile space equals to 2-5 times the width of pile itself. Some theoretical studies on the interaction force relation between pile and soil have been reported and several calculation models were proposed to calculate optimal pile space. A calculation formula is built through dimensional analysis which analyzes the factors that influence the pile space. The new model offers a way for pile space calculation.

The process of construction of Jiuhua Mountain Twin-Arch Tunnel has been simulated with the FEM program. Two excavation methods are simulated; and the stress state and displacement of the surrounding rock during each period of construction are obtained by 2D calculation. The solution that the, three-pilot-tunnel excavation method is better, is obtained by contrasting and analyzing. This analysis provides scientific basis and technical guidance for the construction of Jiuhua Mountain Twin-Arch Tunnel.

Cement-soil retaining wall is widely used for excavation supporting in soft soil area. Aiming at the deficiency of view on correlation between stability of cement-soil retaining wall and its influential factors, orthogonal design method is introduced to analyze the significance and sensitivity of some influential factors such as wall width，embedded depth，shear strength indices，unit weights，groundwater levels and ground load. The analytical result shows that the shear strength indices are the most important and sensitive factors influencing the overall stability of cement-soil retaining wall; and the change of shear strength indices has highly prominent influence on the overall stability of cement-soil retaining wall. But the change of wall width and embedded depth has no prominent influence on the overall stability of cement-soil retaining wall. The conclusions may be useful for the design and construction of cement-soil retaining wall.

The mechanical analysisis an important means for studying failure mechanism of bedding rock slope. Stiffness is strong effects on is to stability greatly. The paper brings forward some viewpoints based on summarizing the existed works. Adopting flexibility to measure stiffness of bedding rock slope, we can achieve the relation between mechanical model, failure character and critical slope length of bedding rock slope. If the value of flexibility is smaller than critical flexibility, bedding rock slope can be simplified to pole model. If the value of flexibility is greater than critical flexibility, bedding rock slope can be simplified to pole or girder model according to actual slope length; and buckling failure of bedding rock slope happens only under special condition.

For in-situ shear test on soil in slide zone，substance constituent，water content and stress history of its samples are all random to some extent; boundary restrain，restoring degree to original consolidation state and draining condition in the course of shearing are fuzzy. All these uncertain factors cause test results become variant and then have no enough geological representation. Applying in-situ shear test parameters and the results of qualitative geology description of failure surface，water ratio measurement and grading analysis to train BP network; and then depending on BP network's ability of high fault-tolerance and strong nonlinear mapping，the shear strength parameters of soil in slide zone are estimated. This method could counteract the influence of the variance of test results to some extent.

By using the uniform hydraulic gradient and variable hydraulic gradient principle, a computational formula of permeability coefficient of the single well(drillhole) steady flow confined fully penetrating well is derived, in which the effect of noneffective drawdown on permeability coefficient is considered, and the most of water level recovery data in computational process are used, while some interference factors effect is excluded in the water level recovery. Therefore, the parameter calculation will still approximate to the fact.

The numerical simulation of slope cutting deformation is carried out with ADINA; and a 2D finite element analysis model is established. And then the influences of two kinds of construction schemes on slope deformations are compared; and the variation regularity of the horizontal shift of bolt is analyzed too. The results show that the side slope unloading distortion and excavation rebound relate to the selection of construction scheme very much.

Traditional plate bearing test of rock mass deformability is based on homogeneous semi-infinite rock mass and Boussinesq formula under centralized force. It can only obtain a synthetic (or equivalent) elastic(or deformability)modulus. The modulus of soft and thin seam(or fault) in rockmasses can not be measured individually. Hence, suggested layered rockmass plate bearing test is not only necessary but also important. According to this test, the rlastic modulus of every layer of rockmasses can be determined using elastic moduli calculation of divided layers .The principle and process, calculation method and application example are presented.

The evolution law and parameters of the model based on finite characteristic ratio theory (FCRT) are determined through the triaxial tests for coarse, medium and fine sands; the stress-strain relation of triaxial tests and that of the model match well. It shows that the FCRT model can describe naturally an important physical phenomenon that the sand samples of different inner grain sizes, which outer size are same, are of the different response properties, such as the strain of the sample with bigger inner grains is greater while other conditions are same.

The monitoring method of the vertical shaft with frozen depth of 460 meters (Most of frozen soil is expansive cohesive soil)is described. By analyzing statistics of different buried length of the frozen wall of the well and concrete block lining of temperature field, three main important rules are drawn as follows: 1. the function relationship between freezing temperature of clay, water content and different buried depth; 2. the rule between the form of different depths of frozen wall and measure of lowering temperature; 3. the development rule in different steps of concrete block lining of temperature field and some other research results. The three rules instruct the construction and monitoring of the shaft effectively so as to support new scientific gist for designing and constructing the identical well.

According to the contrastive in-situ direct shear test of the slide zone in the Three-gorges Reservoir Region in different conditions, changed rule of direct shear strength parameters and the value of c andφ which change along with water content about three kinds of soil of slide zone in different water contents conditions, such as clay, silty clay and the earth-rock aggregate, is researched. Experimental relationship between values of c andφ and water conyenton soils of slide zone is established based on plentiful data; and functionary mechanism of different characterized soil of soils zone caused by water is analyzed; then experimental formula of value of c and φ when water is sluiced or water content changes; finally softening degree of direct shear strength parameters caused by water content(water level changing) is quantified .

This paper introduces geological consitions and results of safety monitoring of the right bank that the diversion tunnel under construction for Jinping-1 Hydropower Project; and analyzes the rules and characters of stress and deformation of surrounding rock and slope. It is shown surrounding rock and slope are stable.

In view of typical representative rock layer in a power plant, the rock shearing creep indoor test is carried out, to research creep characteristic in the rock mass shear failure process. This article selects the extended Burgers model to establish shearing creep equation; and uses the MATLAB tool function fminsearch to fit the nonlinear relation between U and t according to shearing creep test; determines creep parameters of structural plane in the rock mass; and determines its long-term shearing strength according to the direct shear test. Compared to the instant shearing strength, using the long-term strength in design is more reliable to guarantee the project security.

So far, there are two kinds of ways to research soil pressure theory. One is based on limit equilibrium theory and another is based on semi-numerical & semi-analytical method. Classic theories of the soil pressure are obtained by the former, in which soil is regarded as elastomer, rigid-plastic or elastoplastic material. The invalidation of soil is judged by the Mohr strength envelope. In this way, the complex problems become simple. But the theoretical values of soil pressure are different from the actual values. However, for the soil pressure theory based on semi-numerical & semi-analytical method, the function expressions combine with numerical analysis successfully. In contrast with limit equilibrium theory, the later comprehensive considers the distortion of soil, the construction time and the strength index of soil, which make the calculation value of soil pressure in accordance with the actual value. In a word, the semi-numerical & semi-analytical method starts to become new way to research soil pressure.

In the rebuilding of old city, because of the complexity of ambience, foundation pit excavation can cause disturbance to the soil, and bring the distortion of retaining structure, the stability of foundation pit could be lost. Taking an example about foundation pit excavation in complicated environment, the monitoring scheme of foundation pit excavation is discussed; the monitoring result is and analyzed so as to guide construction excavation. The safety of retaining structure and ambience is ensured; informational construction is made.

Soil-cement technique has been widely used in civil engineering. A great many studies on mechanical feature of soil-cement were made, but there are few studying the anti-permeability feature of soil-cement. This paper studies the effects of cement content on permeability coefficient of soil-cement; and the quantitative relationship between them is concluded based on regression analysis. The result also shows that the age of soil-cement has contributed little to permeability.

By mean of the vibration testing measurement, accelerator of vibration and its spacial varied features of the soil and rock slope located in 316 State Road due to the traffic loads were analyzed; moreover the vibration wave signals were analyzed by FFT; and frequency spectrum characteristics of vibration wave were obtained. The results show the information reflected inherent characteristics it carried during vibration wave propagation. The vibration response of soil and rock slope is equivalent sensitive due to traffic loads; the accelerator and amplitude of vibration of the soil slope is greater than that of rock slope under same loads. The vibration response of the soil slope is decreases little by little from up to down along the slope and its attenuation is compared fast in short distant; but the vibration attenuation of the rock slope is compared slow in short distant. Main frequency moves to low frequency with vibration wave transmitting. The testing result will offer reference for analyzing propagated pathway of vibration and its influence on the stability of slope. Furthermore it is of practical meaning to the evaluation of slope stability caused multifarious factors.

A kind of intelligent JRC measuring instrument was developed. It can directly measure rock joint’s roughness coefficient (JRC) of discretional and apply to any producing area and form of rock joints. It also has some characteristics including light weight, small volume, and easy to carry about, simple in operation, quick in mearurement.

Hydraulic fracturing as a technique of geostress measurement has been widely applied at home and abroad due to its many outstanding merits. But this measuring method is only used to the two－dimensional stress in a plane normal to the borehole axis in former time．Recently，the method of by hydraulic fracturing measurement of three－dimensional geostresses is prevalent and has been used successfully in many projects. In Shenzheng Pumped Storage Power Station，the three－dimensional geostresses have been measured by hydraulic fracturing technique to adopt two different measuring methods including in three boreholes with different directions method and in one borehole method, and the measured results are very satisfactory. The latter measuring method was applied in two boreholes that one is in vertical direction and the other one is in approximately horizontal direction. The three－dimensional geostress measured results not only checked the two－dimensional geostress measured stress states in the corresponding borehole’s cross-section and preexisting fissure planes, but also the measured results of the two different measuring methods in the same place confirmed each other; and the measured results confirmed by the results obtained overcoring stress refief method in the same borehole. At the same time, the measured results of the two type methods are very consistent (one borehole measuring methods including non-vertical borehole and vertical borehole), and it can represent the geostess state in the measured area.