Seepage is one of the most important factors which affect geotechnical engineering slope stability. It is significant to study seepage and dynamic change laws under different regimes in rock and soil slope for stability analysis, support design, and engineering water-proof and drainage projects. Using immune evolutionary programming, seepage parameters of left-side rock slope of Longtan hydropower station have been obtained from back analysis. Based on the back analysis of seepage parameters, ground water flow in slope have been simulated under low-water and high-water periods. By comparing the results, change laws of water head under different periods have been summarized, thus providing theoretical basis for slope stability analysis.

In order to study the distribution rule of temperature field in surrounding rock of deeply buried roadways, the mathematical model of thermal diffusion is proposed based on heat transfer and seepage theory. Combined with boundary condition, the distribution of temperature field and temperature vector of surrounding rock under coupling airflow and seepage is obtained by using MATLAB. The results show that seepage changes symmetrical distribution of initial temperature field and vector, and the temperature field in surrounding rock may be divided into inward-diffusion area and out-diffusion area. When heat change between surrounding rock and airflow, wall temperature of roadways will approach to the temperature of airflow; and the scope of zero temperature vector will enlarge step by step. Temperature field of inward-diffusion area is annular and symmetrical distribution when heat change reaches balanced state; and the shape of isothermal curve in out-diffusion area doesn’t change obviously. At the same time, distribution of isothermal curves becomes rarefied.

Taking collapsible loess as research object, this paper presents a numerical model for the finite element analysis by coupling seepage and deformation in unsaturated loess. By comparing the calculation results with the experimental data, it is found that the calculated collapse deformation is bigger than the test data, and this difference is related to the characteristis of un-saturate. So, time is suggested to be considered in the constitutive model of collapsible loess.

Many studies have indicated that the infiltration of rainfall can decrease the stability of filled soil, especially for the unsaturated filled residual soil. Rainfall leads to transient seepage and raise the groundwater level, resulting in an increase of pore water pressure and a decrease of shear strength on the potential failure surface and then failure occurs. To investigate the influence of rainfall intensity and duration on filled residual soil in Fujian region, a parametric study has been conducted using the finite element method. The results show that an increase of rainfall intensity or duration causes an raising of groundwater and change of pore water pressure and seepage velocity, so as to result in the decrease of filled residual soil stability. However, a critical rainfall duration can be identified for such filled residual soil, at which the safety factor is the lowest.

Based on Biot consolidation theory for two-phase porous media, this paper presents a numerical assessment of the performance of a saturated soil slope under rainfall by an effective stress finite element method, in which the soil behavior is described by means of an elastoplastic constitutive model developed within the framework of the Matsuoka-Nakai failure criterion. Firstly, the numerical method and the analysis procedure are briefly outlined. Subsequently, using the proposed method, an engineering case study is illustrated with the simulation of deformations induced by rainfall in a saturated soil slope. Generally, the development of slope deformations is clearly demonstrated by the analytical methods. It is considered to capture the fundamental responses of the problem investigated, and yield results which are useful for engineering practice.

Concrete effective fracture model considering size effect rule was adopted to formulae for equivalent strength of different types of induced joints. The modified formulae for equivalent strength of different types of induced joints are obtained. At the same time, the variation curve of equivalent strength of induced joints is obtained; and the merits between unidirectional interval induced joints and bilateral interval induced joints are compared. It is shown that the properties of bilateral interval induced joints are better than those of unidirectional interval induced joints. Some suggestions are presented for design of induced joints in high arch dam.

The failure rules of brittle rock under uniaxial compression test are studied primarily by using numerical simulation. The brittle rock failure mechanism and the end effect in the numerical simulation test of brittle rock failure are discussed; and some primary conclusions have been drawn. In the uniaxial compression test of brittle rock, tension failure dominates the failure process. Besides the material heterogeneity of rock specimen, the end effect is another important factor to affect the failure pattern of rock specimen. In general, such rules are in existence; the end restraint is more bigger, the failure pattern of rock specimen is more close to “X” dilatancy failure; the end restraint is more smaller, the failure pattern of rock specimen is more close to tension failure.

The mechanical properties of a jointed rockmass under loading conditions are essentially different from those under unloading conditions. The paper makes studies on how bolt consistency, bolt length and rock characteristics to affect the mechanical parameters of a bolt-supported rockmass under unloading conditions. Numerical simulation method and ADINA software are employed. In addition, equivalent deformation parameter method is used to calculate the equivalent deformation modulus and Poisson’s ratio of a jointed rockmass and bolt-supported rockmass. Based on that, the paper analyzes the relation between the equivalent deformation modulus En of bolt-supported rock mass and bolt consistency N, and the relation between En and bolt length L.

Model experiments of the geomaterial models, plaster cast models, sand mortar models are conducted. Though analysis and fitting of the results obtained from model experiments, an initiatory increment constitutive model of unloading jointed rock masses is proposed. Aiming at deficiency of the constitutive relationship, new model through amendment based on parameter choosing and physical meaning is obtained. Then the constitutive relationship is incorporated into ADINA, the analysis for the high slope model of Geheyan Hydropower Station is performed; and the calculation results are compared with those by loading method. The rationality of the constitutive relationship is verified finally.

Although the mechanism of finite strain consolidation (FSC) theory is rigorous, its inherent complexity and non-linearity lead to the present controversy on the difference between foundation settlements predicted by FSC theory and by small strain (SS) theory. Based on fundamentals of continuum mechanics, the FSC incremental finite element (FE) equations with total Lagrangian (TL) description are formulated using soil mechanics sign convention; and the corresponding reduced FE equations for total stress analysis are also obtained. Through a case study, the influence of material linearization method and material geometrical bi-linearization method on the results of FSC theory is analyzed with the discussion of the appropriate length of sub-load step, and the difference between the ultimate settlements by FSC theory and SS theory are probed. The results show that the predicted settlements by linearization methods are sensitive to the length of sub-load step; the settlement by FSC theory is larger than that by SS theory, due to the effect of different stiffnesses under tensile and compressed state in geometrically nonlinearty problems; the initial stress matrix plays an important role in calculating the ultimate settlement by FSC theory, etc.

Initial stress is one of the key factors for rock engineering, and is one of the elementary indexes required in design, especially for large hydroelectric engineering. The study on in-situ stress field of rock mass around the dam area of Baihetan Hydropower Station had been carried out. Based on the means of numerical simulation with three-dimensional distinct element code (3DEC), the rock mass natural stress of a valley has been simulated. The result shows that the stress distribution has three areas: the area of loosed stress, the area of concentrated stress and the area of stable stress, which is according with typical stress distribution pattern in a deep valley. What is more, the calculations fit well with in-situ measuring data by using hydraulic fracturing method including 6 points. The simulation results delineate clearly the whole outline of the stress field of dam site, and provide important basis for analysis and design.

The solution of Laplace equations by using the method of separation of variables in the cylindrical coordinate system is discussed. Through a series of case studies, the solution of Laplace equations is gotten and used to study the phenomenon of seepage failure and exemplify some instances. It concludes that the ununiformity of the permeability coefficients is the main reason for the seepage failure; and the seepage failure always develops along the direction of high gradient of the permeability coefficients. The authors also try to probe into the complicated mechanism of piping. This study is of great significance to some engineering problems, such as piping, flowsoil, etc.

The characteristics of stress distribution has been studied based on the measuring data in Three Gorges Project. There is obvious difference between shallow and deep tectonic stress states, the direction of the maximum horizontal principal stress is NEE at shallow depth, but it is NW at great depth, and is NNE at permanent shiplock at shallow depth. The characteristics of stress distribution in permanent shiplock before and after excavation has been studied. The stress states have been readjusted and distributed before and after excavation in permanent shiplock; the stresses in the EW direction increase or decrease at different altitudes in the slope rockmass; the stress release is smaller. The stresses in the SN direction decrease in middle and upper part in the slope rockmass; stress release is rather large; and there is stress concentration at grading angle part after excavation. The direction of maximum horizontal principal stress rotates in clockwise, change from NE to EW direction with the excavation of permanent shiplock.

There are two kinds of standpoints on the mechanism of hydraulic fracturing of soils, that are tensile failure and shear failure. Vast studies on the fracture mechanism as well as the corresponding theoretical formula of the fracture pressure appeared in literatures, however, their explicabilities were still not yet fully discussed. The computing methods of the fracture pressures for tensile failure and shear failure in three dimensional stress states are put forward in this paper. Base on Mohr-Coulomb failure criterion, the applicability of the proposed fracturing pressure calculating method is discussed. The results indicate that the hydraulic fracture criterion is related to the minor principal stress and undrained shear strength of soil; and the possibility of shear failure increases with the minor principal stress σ3 increasing. The hydraulic fracture test results in literatures verify the applicability of the proposed method.

It is important to evaluate the in-situ bearing capacity of rock-mass effectively for the design and running in safety of hydro-engineering. Based on the measurement data, the evaluation method of in-situ bearing capacity of rock-mass has been studied. The evaluation method of in-situ bearing capacity of rock-mass in long term high hydraulic head is prsented with definite physical meaning. The method and theory of hydraulic fracturing and one step water pressure test are also discussed. The relation of in-situ bearing capacity of rock-mass, in-situ stresses and pore pressure has been studied. The time-effect and its influence of in-situ bearing capacity of rock-mass is discussed. The value range of in-situ bearing capacity of rock-mass is proposed depend on the effect of fracture normal stress and pore pressure.

Based on the theory of plane strain, 2D elastoplastic FEM is used to analyze the behavior of composite soil nailing support of deep foundation pit, and evaluate the stability of the soil-nailed wall. The difference between composite soil nailing support and normal soil nailing support are compared; and the influence of supporting parameters on the deformation behavior and stability of foundation pit are analyzed. Some useful conclusions are drawn to supervise the design and construction.

Due to the complexity of geology condition and the variability of soil, the soil parameters employed in calculation of ground subsideence are empirical values; they are usually uncertain. It is more serious for the calculation of ground subsidence of large scale area. Based on the Biot consolidation theory, numerical analysis and the FEM software –Adina, a land subsidence model of water withdrawal of single well is established; and the effects of sensitive parameters of ground subsidence during the water withdrawal and the appropriate parameters are determined.

The calculation method for settlement of soft soil foundation is introduced; and it is used to calculate the settlement of soft soil foundation of Baoguosi travel road. According to the settlement data of soft soil, the soil parameters are gotten by least square method. Finally, the settlements after construction at 9 sections of this road are estimated by the proposed method.

Unsaturated hydro–mechanical coupling of fractured rock mass has important influenee on the strength and stability of rock mass. In recent years, the research of saturated hydro–mechanical coupling has achieved some advances, but saturated flow can’t be adopted simply in many practical projects. Based on the mechanical theory of DDA and fluid flow analysis of fractured network, unsaturated hydro–mechanical coupling analysis model is put forward naturally. And then taking a reservoir rock slope for example, the stability of rock slope is discussed when water level of reservoir falls. And it is shown that the safety factor is lower when the water level falls quckly and when considering coupling; it is consistent with the fact.

Element free Galerkin method (EFGM) is a meshless numerical method by constructing interpolation function with moving least squares (MLS) interpolation. Based on the interpolation function of EFGM and its derivative function, the governing equations of EFGM to deflection solution of elastic orthotropic Mindlin plates bending on Winkler elastic soil foundation are achieved by variation principle. Computation program is designed according to this theory. Numerical results indicate that the above method is feasible and effective to solve the elastic foundation plate problem in hydraulic structures.

Studying the changes of mechanical performance for damaged structures and components have widely drawn the interests of researchers in the world. One can find that from the literature, most of the researchers in this field study damages of the structures according to the theory of equivalent strain based on continuum damage mechanics and fracture mechanics. The conception of equivalent stiffness is used in this paper to simulate structural damage severity. Using this approach, an analytical model, which includes three damage parameters（damage location, damage severity, and length of damage）, is developed for cantilever beams. Solutions for the displacement along the cantilever beams under dead load, for both 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 displacement for damaged cantilever beams are summarized from comparing the numerical values. The purpose of this paper is to lay groundwork for future studies about structural health monitoring and damage identification.

There are many fractures in natural rock mass. The stability of rock engineering is severally affected by the seepage of water through these fractures. So, determination of the permeability coefficient of those fractures is very important. The back analysis is a suitable method to determine those parameters. But it is a complicated optimum problem of nonlinear function of back analysis of seepage parameters for rock mass. To solve this problem, there exist a lot of shortcomings to use traditional optimum methods, including genetic algorithm. So, a more suitable bionics algorithm, immunized evolutionary programming proposed by the author is used to solve this problem. At last, this new back analysis method is tested by a typical example. The results show that, the permeability coefficients by proposed algorithm are close to the real ones that can be gotten only through the known water head results.

It is known that the distribution of the active earth pressure against a rigid retaining wall is not linear but nonlinear. Based on the unified strength theory, the formulations of the unit earth pressures, the resultant earth pressure and its acting point are given for the wall rotating about the base by analyzing the slice elements extracted from the sliding soil wedge. The formula takes account of the effect of intermediate principal stress. It is demonstrated that the strength theory has great influence on the earth pressure; and the potential strength of the filling materials is sufficiently developed under the guidance of the unified strength theory.

Computation of earth pressure considering the displacement of retaining wall is very important to engineering design. However, theoretical analysis of this problem is very infrequent. Based on analyzing earth pressure changing with retaining wall displacement, a new model considering the retaining wall displacement is established for both passive earth pressure and active earth pressure. Through the study and analysis with the new model, some calculations to the earth pressure of retaining wall are drawn.

The stress state of the sliding soil behind a rigid wall rotating about base is analyzed in detail. The relations among the reactions on wall and sliding surface, and shear stress and vertical pressure of the horizontal soil strata are established. The friction angles of the wall and sliding surface are reduced in order to consider that the soil near base don’t reach the limiting equilibrium state. Based on the horizontal soil slice element method, the stratum by stratum calculational method is set up to obtain the vertical earth pressure acting on the surface of stratum by considering the shear stress of the strata, the change of angle of horizontal of the failure line and the friction angle of the wall. The unit earth pressure, the resultant earth pressure and the point of application of the resultant earth pressure on the retaining wall are also obtained. It is demonstrated that the obtained unit earth pressure is consistent with the experimental observations; and the resultant earth pressure is larger than that of coulomb’s solution. The width of the topper curved sliding surface is smaller than that of coulomb’s solution; but it is consistent well with the engineering observations.

The main dam of upper reservoir of pumped storage power station in Yixing of Jangsu is a concrete-faced rock fill dam. In order to reduce the amount of work, a high concrete retaining wall is constructed on the downstream to bear the earth pressure of upstream rock fill. As earth pressures are very critical to the stability of the retaining wall, this paper plays emphasis on the comparison between calculated value and actual measured value of earth pressures on high retaining wall, and also makes corresponding analysis.

Mixing dredged sediment with EPS beads and cement can not only reutilize of dredged sediment, but also produce a geotechnical material with low density and high strength. Strength is one of the most important properties ofEPS beads mixed lightweight soil. For engineering design, it is necessary to build the relationship between the shear strength and the properties and ratio of the materials. The strength is controlled by solidifying effect of solidifying material and replacing effect of EPS beads. The solidifying effect has been researched a lot, so the replacing effect is studied in this paper. The relationship between cohesion of EPS beads mixed lightweight soil and the density and content of EPS beads was built based on equivalence of force, coordination of strain and physical properties of EPS beads. The cohesion of EPS beads mixed light weight soil was obtained by direct shear test to verify this relationship.

In the method of response surface Monte-Carlo based on artificial neural network, the uniform design, a kind of design of computer experiments, is introduced to arrange training samplings set of RBF neural network that combines the advantages of uniform design and RBF neural network organically. On the one hand, it may decrease the number of training samples as fully as possible, and on the other, it fills training samples into the parameter space uniformly, and enhances the prediction accuracy of RBF neural network which has strongly local approximate capacity. In the probability analysis of retaining wall stability against sliding, for example, the results of the proposed method are very consistent with those of the direct Monte-Carlo simulations. And in addition this probability analysis shows that friction coefficient of the wall base f, the inner friction angle f ,unit weight γ of filled soils, and the friction angle of the soils against wall back δ have influences on the retaining wall stability against sliding from high to low in turn.

In order to improve the accuracy and overcome the extra learning problem of ANN, a new method coupling genetic algorithm (GA) and support vector machine (SVM) is proposed to forecast the grouting in the fractured rock mass. By learning samples, the SVM model with optimal penalty factor and kernel parameter which are searched out by using the SVM predicting error as the fitness of GA is established which can reflect the nonlinear relation between the grouting and its affecting factors. The practical examples have been computed to testify the efficiency and ability of this method; and the calculational results show that the method has rapid speed and sufficient predicting accuracy.

Based on the finite cover techniques of manifold method, the displacement function of bolt was determined according to the cover system of manifold element; and the numerical manifold model of fully-grouted bolt was established; and the concept of bolt manifold element as well as its numerical calculation form were obtained. This model meets the physical meaning of fully-grouted condition; it is a numerical method of bolt with feature of partial analysis and better calculation accuracy. At the same time, bolt and mathematics cover are relatively independent, only the bolt is required to be in mathematics grid, while no have strict requirement of their relative location has to be met, so general grid can meet complex configuration of bolt. This model can be used in simulating geotechnical bolt and analyzing the interaction of reinforcing bar and concrete.

In order to solve the initial surge height problem triggered by landslide in reservoir, the surge is summarized into two kinds on basis of the mechanism of landslide surge, respectively, volume-surge and impact-surge, and their heights are calculated by the volume conversation law, the continuity law of flow and viscous force formula in flow field. The volume conversation law is used to obtain the relationship between landslide volume and surge height, the continuity theory of flow is used to get the relationship between surge speed and surge height, and the viscous force formula in flow field are applied to solve the relationship between displacement and speed of mass in water. Taking Xintan landslide as an example, we can draw the conclusion that the initial surge height increases first and then decreases, and this change is different with that of landslide speed .

With the development of municipal engineering, shield tunneling has been used in various kinds of underground constructions and underlines more popularly in urban area. Much more attention should be paid to the effect of tunnel construction on close environment. According to the space regularities of distribution of ground loss and by stochastic medium theory, it is assumed that ground movement process is of the property of stochastic process, and the soil displacement due to ground loss can be calculated. Combining with the basic elastic equations, the stress changes due to tunnel excavation can be calculated. Finally, with the help of computer programs, the soil displacement and superimposed stress are analyzed, which can help researchers to understand the environment effect of construction. And at the same time, these results can make(be of great help ) for in-situ engineers to make decisions on their own on these effects in advance.

The thermo-visco-elasto-plastic constitutive differential equation under uniaxial compression has been deduced based on Nishihara rheological model considering the spring’s coefficients of thermal expansion. Through analyzing the creep and unloading curves, the Nishihara rheological model considering the effect of temperatures is in a stable creep while the stress is low, which contains instantaneous elasticity, elastic aftereffect and viscosity flow caused by temperature. The model in a high stress level is an unstable creep, which also contains instantaneous elasticity, elastic aftereffect, but the viscosity flow is caused by the mutual action of temperature and stress. The creep properties of rocks subjected to changing temperatures can be comprehensively reflected using this model.

The three-dimensional elastic model for the predicting analysis of ground surface subsidence due to underground mining is established based on plate-shell bending theory. And the relative theoretical formula is deduced and applied to analyzing ground subsidence due to underground mining in Xiaoguanzhuang metal mine, Shandong, Province China. Matlab is used to calculate the numerical integration and draw the figures. The engineering example shows that the theoretical results are consistent with the field measurements.

To fit the water level rise and improve the flood control standard, the dam usually is widened. New widening part of the dam can induce the nonuniform post-construction settlements and lateral displacements, which will influence its stability. The finite element method is used to analyze the influences of the widening width, ground treatment, geogrid’s character and layout manner on the project character of the dam. The calculation results show that by the above means, the stability of the dam can be improved; and the post-construction settlements and lateral displacements can be decreased. The conclusions can be for reference to similar projects.

Two diaphram walls are frequently used in the rock-filled wall with a high core on the rock cover. Referring to the condition of a certain high rock-filled core dam with a nearly 50 m deep gravel-sand overburden, the steady seepage fields of the dam base in 6 set-up schemes of diaphram walls are analyzed using the finite element software developed by the first author, and the ratio of the hydraulic head acting on the main wall, secondary wall and gravel-sand layers in each scheme is obtained. The hydraulic head acting on the gravel-sand layers is less than 3 percent of the total in these schemes. In the schemes in which the water-tight curtain under the secondary wall is the same as that under the main wall and the round seepage between the two walls is blocked by the side water-tight curtains, the hydraulic head acting on the secondary wall is only slightly less than that on the main wall. If the side curtains are omitted, the hydraulic head on the secondary wall is only 20 percent to 30 percent of the total. If the curtain under the secondary wall is further canceled, the hydraulic head on the secondary wall will be decreased to 8 percent to 11 percent of the total. The hydraulic head on the secondary wall in the upstream side of the main wall is less than that in the downstream side. The hydraulic head ratio of the two walls is not sensitive to their thickness.

The water or soft matter is often filled in the fissures of rock masses. The fracture of a rock-mass fissure under the internal pressure is an important problem in the geotechnical engineering. It is simplified as the plane stress problem of a fissure loaded by I mode with a pair of internal point forces in the finite rock mass. The plastic stress fields in the zone near fissure line are solved using the near fissure line method on the basis of the failure criterion of rock bridge material and differential equilibrium equations. By matching the plastic stress fields with the reasonable elastic stress fields at the elastoplastic boundary, relationship between the internal pressures and cracked region lengths on the fissure line is obtained. The bearing capacity of rock bridges is also given.

The stability of rock mass is affected by many undetermined factors having random and fuzzy behavior. And it belongs to the fuzzy probability category. To assess the stability of rock mass with classical fuzzy comprehensive assessment methods may lead to incorrect results. Based on the fuzzy probability theory, a new comprehensive assessment method for the stability of rock mass (Fuzzy Probability Evaluation Method) is presented in this paper. The fuzzy weighted values are established to avoid the uncertainties while determining the index weights. Five factors which affect the stability of rock masses are picked out. For each of them a subordinate function and fuzzy weighted value are established. An example of underground rock mass engineering is introduced at last. Stability grade of surrounding rock of the underground engineering is analyzed using the Fuzzy Probability Evaluation Method. The analysis process is introduced and the results are compared with other methods. It has been proved that the method of this paper is reliable and practical.

A stress-strain-time function of saturated over-consolidated clay is presented; in which a modified hyperbolic function is adopted for stress-strain behavior and a power function for strain-time behavior. Through introducing over-consolidation ratio and brittleness Index, not only strain hardening stress-strain-time behavior, but also strain softening stress-strain-time behavior can be simulated by it; so that it is more universal than strain hardening stress-strain-time function. Through simulation of computed curves by different models and test data of constant strain ratio test, such a generalized function is proved to be reasonable.

The soil under the piled raft foundation system was simulated by linear extended D-P elastic-plastic soil model. 3D finite element model of ABAQUS program was established to obtain some behaviors of the piled raft foundation system by comparison of load-settlement curves of several foundations. Composite pile foundation design method was studied and improved combined with Code for Design of Building Foundation (GB5007-2002), then the three-stage concept was discussed. Computation results show that these two methods are more economical than conventional design methods.

In geotechnical project, the geotechnical strength parameters ( ) are very important, their values exert a great impact to the safety of the project. In previous analysis, those parameters ( ) were studied independently, so that the correlation between them is ignored. On the basis of geotechnical parameters submitting two-dimension normal distribution, the Bayes method to optimize the probability distribution is introduced. The coefficient of variability of the geotechnical parameters after optimization is reduced greatly; the feasibility of this method is proved by using the example of Jinping Hydropower station.

The reinforced concrete branch pipe subject to high hydraulic pressures of Huizhou storage pumped station, because of its PD value exceeding 6000, complex structure form, complex hydrological geology and engineering geology, is the key and formidable problem of the project. Based on permeable tunnel design theory, the followings are computed separately: the branch pipe excavation country rock crustal stress field in the construction period; the steady seepage of high pressure branch pipe, the concrete line’s stress-strain and country rock safety in the operation period; the concrete line’s stress and strain in the emptying inspection period of high pressure branches. The high pressure branch’s reinforce steel is also computed.

Under the Barron’s equal strain condition, the plane model of sand-wall ground consolidation considering the effect of well resistance, combined radial and vertical flow and lateral displacement of soil is established. Based on the theory of homogeneous sand-drained ground consolidation by Tang Xiao-wu, under the condition of the consistency of average excess pore pressure at any depth, the equivalent transpositional formula of plane model of sand-wall ground is presented. Thereby, the complicated spatial problem is simplified as the plane problem. This method can reduce the amount of sand-wall elements, with only adjusting the coefficient of permeability. The effectiveness and reliability of this equivalent transpositional formula are validated by comparing the numerical solutions of FEM in case of plane strain and PDSS (plane deformation and spatial seepage).

There are a lot of settlement prediction methods with their own advantages and limitations. In order to utilize as much as more useful information, a new forecasting method combining many models based on entropy weight has been put forward, which can forecast the embankment settlement by using limited measured data. The analysis of an engineering example indicates that the new method has high precision and obvious advantages.

Results of triaxial test indicates that, due to low porosity, asphalt concrete used in hydraulic engineering has obvious lateral effect and smaller volumetric deformation, and takes on shear-swell characteristics. It is hard to reflect the special stress-strain relationship of asphalt concrete through existing nonlinear models or elastoplastic models. Considering that asphalt concrete does not complying with associated flow rule and Drucker postulation and the elastic coefficient is changed with the plastic deformation. The author suggests a double-yield surface model with elasto-plastic coupling; and it is satisfied with the result of indoor triaxial test.

Based on the theory of reinforcement and assuming the fracture surface of reinforced embankments is a log-spiral failure surface,the limit analysis method is used to deduce the critical height of reinforced embankments. The solution is consistent with the critical height of unreinforced embankments when the force is not consider. It is concluded that the critical height can be improved through reinforcing embankments.

The characteristics of correlation distance of soil properties applied to geotechnical engineering are studied. And the basic method to calculate the correlation distance by correlation function is presented. The choosing criterions of standard correlation function are also discussed. It can be drawn that the value of correlation distance calculated by correlation function is reasonable when the standard correlation function is exponential function, especially single exponential function. At last, the paper provides the correlation distance of three representative soil layers in Shijiazhuang bridge east district, which will be useful for borehole distribution and sampling distance.

The effects of the stabilizing piles on the stability of a slope are simulated. The shear strength reduction method is employed in the analysis, and the zero-thickness elastoplastic interface elements are adopted to simulate the soil-pile interaction. The effects of the spacing and position of the pile on the safety factor of the slope, as well as the behaviors of the piles under these conditions, are given. The calculated results show that under the maximum safety factor, the place where the pile should be installed is associated with the depth and position of the sliding surface; and for the embankment slope, installing piles at the toe of the slope is safe. Appropriate reduction of the spacing of the piles is beneficial to the improvement of stability of the slope and the exertion of the effect of soil arching.

A Burgers model with non-stationary parameters was presented in this paper based of the study on the shear creep experiments of the interlayer in Jinping Cascade 2 Hydroplane project. Because it takes into account the character of partial parameter that their value change with the passage of time, this model can not only describe the process of acceleration creep stage, but also is better than Burgers model with stationary parameters to describe the process of initial creep deformation and the process of steady creep deformation. Burgers model involve too many parameters, so particle Swarm Optimization (PSO) algorithm is adopted to identify the model parameters, and the results are satisfactory.

The result of planar Finite .Element Method (FEM) is commonly expressed by isolines, and Surfer is a software widely used to draw isolines, yet Surfer has many shortcomings, for example, some isoline values can’t be judged. Based on FEM mesh and linear interpolation and other artifices, a VBA program is compiled to overcome the shortcomings, and the isoline can be directly formed in the interface of AutoCAD, that is a widely used cartographic software. The VBA program can be applied to draw isolines in the planar FEM postprocessing.

Karst disaster is one of familiar geology disasters in tunnel construction in mountain area. The influence of concealed caverns on the stability of tunnel surrounding rock in tunnel construction in karst region is studied. The stability problem of tunnel roof under the influence of jumbo size concealed karst caverns is simplified to collapse destabilization problems of beam or plate. The analytical formula of the minimal safe thickness of karst tunnel roof is deduced on basis of elastic theory. The stability of tunnel roof in Wudu Reservior is analyzed by this formula; and the rationality and creditability of the formula is verified by in-situ test.

The moment force model for the soil shearing failure analysis is introduced, and the shearing failure process is analyzed. Then the moment model is used to explain the formation of the shear band under-cut broken angle of clay. Groundwater is the key factor which does more harm to the foundation pit project. How to analyze and study the effect of groundwater on the project is a difficult and important subject. Based on the destruction effect of groundwater, the change of interface with the variety of groundwater is analyzed; and the equation to calculate critical angle of planar slide under saturation condition is deduced.

The method employed to determine the plastic critical load and plastic zone is based on Mohr-Coulomb criterion and a hypothesis that the coefficient of the lateral earth pressure is unit along inclination. It is found that the settlement obtained by this method is larger than the actual situation. Considering change of coefficient of lateral earth pressure along inclination, two methods are constructed to determine the plastic critical load and plastic zone. One is based on Mohr-Coulomb criterion and the other is based on three generalized Mises criterions. The computational results show that even the normal stresses are reasonably cut down the plastic zone from the first proposed method is larger than that from the present employed method for ignoring the intermediate principle stress. The shapes of the plastic zone obtain from three different criterions adopted in proposed method are similar. The plastic critical load, gain from the generalized Mises criterion whose circle is circumscribe to the exterior angle of Mohr-Coulomb’s scalene hexagon, is almost equal to that got by the present employed method, but the corresponding plastic zone is smaller.

Based on the kinematic method of limit analysis and the shear strength reduction technique, the equation for expressing the critical limit-equilibrium state is formulated and employed to define the factor of safety and its corresponding critical failure mechanism by mathematical optimization method for a given slope subject to pore-water pressure and seismic load. The presence of pore water and seism can be embodied through work terms in the energy balance equation, and water pressure and seismic inertia force are considered as external forces similar to gravity and surface tractions. The traditional definition of factor of safety is adopted in the present method so that the results from the limit analysis can be directly compared with those from methods of slices. Through numerical analyses for several typical examples, the reasonability of the method is verified. Numerical computations are made to examine the influence of pore water pressure and horizontal seismic acceleration coefficient on slope stability.

Because of the cutting of fault and joint, most of rocks in slope is discontinuous. And the rainfall penetration is some most important factors affecting the stability and deformation of rock slope. Based on the unstable saturated-unsaturated seepage theory, an unstable saturated-unsaturated seepage analysis model is set up for the rock slope, and by use of the discontinuous deformation analysis(DDA), a stability analysis model is established for rock slope considering the effect of unstable saturated-unsaturated seepage field under rainfall penetration. Taken as an example, the effect of unstable saturated-unsaturated seepage field under rainfall penetration is analyzed in detail for a rock slope of a highway road, and the factor of safety is estimated.

The technique of shear strength reduction and the criteria on the basis of non-convergence of iterative computations are incorporated into the large general-purpose FEM analysis software, ABAQUS, to automatically search for the most critical strength reduction factor as safety factor. Then, the non-convergence criterion of numerical solution is successfully used in the stability analysis of layered clay slope and multi-stage slope. Moreover, the consistency of Mohr-Coulomb yield criterion used in ABAQUS with that in traditional plasticity theory is demonstrated.

The Dayantang landslide is located at the dam’s back side of Shuibuya hydrolic project in Qing river, and it is in the center of strong atomized rain brought by flood discharging of spillway. For atomized rain influences groundwater table of landslide obviously, the stability of landslide is not optimistic. This paper simulated groundwater table of the landslide under natural rain and high atomized rain with three-dimensional saturated-unsaturated stable seepage finite element method, and mostly compared the seepage-control effects of different anti-seepage measures.

An extension version of discontinuous deformation analysis (DDA) is presented. In order to calculate the safety factor of slope, the shear strength reduction technique is accomplished in the self-developed DDA program. Two examples, one is a high rock slope and the other one is a gravity dam, are simulated using this extended DDA program. From the results, we can find that the stability safety factor of rock slope can be calculated by DDA with shear strength reduction. But the safety factor of gravity dam from DDA is lower than that from limited equilibrium method and FEM. DDA coupled with FEM can give a reasonable factor of safety. The results show that DDA or DDA coupled FEM with shear strength reduction technique can be used to calculate the factor of safety and simulate the failure process of slopes.

Among the methods of arch dam stability and slope stability analysis, the finite element method (FEM) can take almost all factors into consideration； especially seepage，material constitutive relationship ，structure a deformation, stress distribution ,complicated material distribution and boundary contact status etc. But there is no corresponding evaluation system provided by the design code. On the contrary, there are specific indices in the rigid body limit stability analysis. In this paper, the FEM results are re-analyzed with the limit stability analysis formula, to get the similar safety factors, which could be easily compared and estimated. Finally, the method has been successfully applied to Jingpin Arch Dam design.

The effects of the confining pressure and pore pressure on the post-peak characteristics of the stress-strain curve of rock mass are analyzed in this paper. The apex post modulus is define to indicate the effect of the pore pressure transition of the stress-strain curves, the stiffness criterion of the landslide, the effect of the post-peak slope of the stress-strain curves is further analyzed. With the pore pressure increasing, the post-peak curve becomes steep, and the post-peak stiffness augments, that is , the homogeneity and brittleness of the material increases and the stiffness ratio k decreases. Therefore, under the same environmental and systematic conditions, there is a critical value for the stiffness ratio of 1. When the pore pressure surpasses the value , the landslide is inclined to be induced by rainfall. Rainfall is an important triggering factor of landslides.

Bachimen landslide, located in Fujian Province, China, is the current largest landslide occurred during the highway construction; monitoring is the important content among landslide dynamic design and information construction. A large scale monitoring system is built in this landslide, this paper discusses the monitoring system design, in situ layout of monitoring facilities and testing methods in detail. Monitoring items consist of surface displacement, horizontal displacement of landslide body and anti-sliding piles, soil pressure behind anti-sliding piles, tensile force of anchor cables, cracks and underground water level. Based on the synthetic analysis of typical monitoring results, sliding direction, slip surface, displacement of landslide body, the variation of anchor cables’ force and underground water level are all obtained, which provides direct proofs not only for dynamic remedial design, but also for the safety construction. Furthermore, the monitoring system makes it possible for the landslide deformation and residents’ on the landslide are all far away from abnormal serious condition. In the result, the remedial construction keeps safe and engineering cost is greatly saved, which will provide significant reference for those relevant landslide monitoring projects.

The bank slope always responds well to its stability when the Three Gorges Reservoir water level fluctuates. A research was done to gain the equation of saturation line when the reservoir water level declines from 156m to145m in a steady speed and from 156m to a height in a steady height. Multinomial fitting was introduced to work out the equation for the initial saturation line. As a typical example, the bank slope of red beds to the northeast of Qianjiangping slope was analyzed and the stability coefficient of the bank slope was calculated when the reservoir water level declines. The results show that when the reservoir water level declines in a steady speed, the higher the speed is, the bigger the deducing rate of the stability coefficient is; the higher the declining speed is, the more remarkable the hysteresis of the groundwater is, but the hysteresis will reach to a peak as the water level declines; when the reservoir water level declines in a steady height, the relation curve between the height and the stability coefficient presents three segments with different declining ratios. As to the slope northeast to Qianjiangping landslide, the critical declining velocity is 1.2 meter per day while the reservoir water declines in a steady speed. When the reservoir water declines in steady height, the critical condition is that the single declining height must not beyond 6 meters. It is significant to guide the prewarning and forecasting of geologital disaster which is similar to the bank slope in the Three Gorges Reservoir.

Probabilistic neural network is applied to facilitate slope stability estimation by making use of data mining technique and intelligent system. Data mining can draw attention to meaningful structures in the archives of such slope stability data. The soil mechanical characteristics and the slope shape with significant influence on slope stability are used to train and test the neural network. Validation is performed to show the efficiency of probabilistic neural network for estimation of slope stability. The simulation results show that probabilistic neural network model generate higher predicting precision than the conventional linear regression, limit equilibrium method and maximum likelihood estimation.

To study the stability of spillway side slope of a hydropower station under serious atomized rainfall, the saturated-unsaturated numerical model considering the seepage of the atomized rainfall is conducted to a typical section of slope. The atomized rainfall infiltration induced saturated-unsaturated seepage flow fields is simulated by the finite element method; and base on this, the stability of the slope is evaluated by the unsaturated point safety factor method. The results show that the instability of the slope is mainly caused by the decreasing shear strength, the slowly increasing pressure head and the temporary saturated region, which are induced by the atomized rainfall; The findings can provide reference to the design of slope drainage.

In the period of impounding and running of the Three Gorges Reservoir, the sensitive degrees of change of groundwater table and displacement to the fluctuation of water level are different in different parts of landslides induced by the fluctuation of water level (as the case of Xietan Landslide). According to the relationship between different sensitive degrees of monitoring variables (underground water level and displacement) and quantity of monitoring information, the sensitive zones of groundwater table and displacement to the fluctuation of reservoir water level are divided into different degrees by the approach of fuzzy pattern recognition. The result of numerical subarea of sensitive zone of groundwater table and displacement indicates that the middle and front part of the landslide are the main places with groundwater table affected by the fluctuation of water level of reservoir; the variation of horizontal displacement of surficial part of the middle and front part of the landslide is more sensitive to water impounding and sudden fall of water level; and with the increase of elevation and depth of the landslide, the horizontal displacement changes less and less; the change of vertical displacement of surficial parts of the landslide is most sensitive to the fluctuation of water level of Three Gorges Reservoir; and with the increase of depth, the change of vertical displacement become smaller and smaller. By the means of the numerical subarea regulation of Xietan Landslide, the suggestions to the point layout for monitoring the groundwater table and displacement in the landside of Three Gorges Reservoir are put forward.

Aiming at the complexity and localization for common methods of slope stability evaluation, this paper combines fuzzy mathematics theory with AHP and establishes a comprehensive model of slope stability evaluation. Meanwhile, the paper uses this evaluation model to analyze the stability of high slope of Geheyan PowerStation . The result indicates that the model makes slope stability evaluation more comprehensive, more scientific and clearer to the truth. It is feasible and its result is reliable. It provides scientific basis for project decision-making .

Rock mass slope saturated and unsaturated seepage issue under flood discharge atomized rain is a major problem which will be faced in the high dams of the southwest area of China. Firstly, the movement character of slope water and factor influencing the seepage under the flood discharge atomization is analyzed theoretically. Secondly, according to the control equation of saturated-unsaturated states, the integral saturated-unsaturated unsteady seepage control equation is constituted in connection with saturation degree. Thirdly, the three-dimensional FEM program for computing saturated-unsaturated unsteady seepage under ground permeation condition is developed; the unsaturated hydraulic parameter problem and initial water head field problem in the FEM is treated. Finally, based on the proposed method, the seepage field under flood discharge atomization of slope in Goupitan Hydroelectric Station at right bank is simulated. The result can provide an important reference for slope rock mass seepage control. The result shows that the flood discharge atomized rain seepage can lead to temporary saturated area in the slope surface and groundwater table hoist; the temporary saturated area size and groundwater table amplitude depend on the protection of slope surface, drainage and purdah etc. So, the slope surface protection should be strengthened, and the measures of drainage, purdah of slope should be set up rationally in order to reduce seepage and groundwater table hoist.

Failure of soil slope is a developing process from local soil failure to overall failure of slope. And the extension of plastic zone and the change of lateral displacement increment of soil slope exhibit the process perfectly. Based on the actual failure of slope and numerical simulation of finite element method, the abruptness of lateral displacements increment at characteristic location and connectivity of plastic zone are suggested to be the instability criterion of slope. The failure behavior and stability of soil slope is analyzed by using the criterion and large deformation finite element method based on shear strength reduction. Moreover, the failure behavior and the stability of clay slope with weak layer are analyzed and the numerical results of large deformation finite element method are compared with that of small deformation finite element method. The results show that the failure behavior of clay slope with weak layer varied with the soil property of weak layer. And the safety factors of slope stability are coincident relatively, but the changing points of slope failure mechanism varying with soil property of weak layer are different.

Taking the excavated slope at powerhouses of Wuxi Mashan Pumped Storage Power Station for example, the corresponding geological profiles are analyzed in detail; and the possible slides are found out. Using the limit equilibrium analysis and finite element method, the stability and the relationship between stress and strain of four profiles are analyzed. The results show that the values calculated by limit equilibrium method and FEM are closed; and they are satisfactory with GB standard; the maximum displacement of slope occurs at the elevation of -20m and 5m, the value is －22 mm; its maximum principal stress is located at the elevation of －45..0 m, and its value is 0.134 MPa; the minor principal stress is －6.22 MPa. In addition, the time-dependent characteristics of the slope should be discussed in future study.

The particle flow analysis method is introduced and applied to simulate a rock slope. The joints are formed according to the practical data; and the mechanical parameters of joints are smaller than those of the rock. When the retaining wall below fails to function completely; the movement process of the landslide is calculated and forecasted; and the deformation of the whole landslide, displacements and stresses of various positions, are analyzed. The upside powder clay slips resulting from ripping within itself, while downside gravel slip because of the destruction of the retaining wall and decrease of the tensile stress. The 2 sliding planes are determined and the suggestions for treatment are proposed.

According to the practical experiences in the expressway construction in the mountain region, the form and position of the slip curve surface, and the ultimate bearing capacity are found out by the large scale model experiment. Based on the generalized limit equilibrium method, the computation procedure for the stability analysis of embankments on the mountain slope is programmed by using Visual Basic. The model experiment is calculated by this program; and the calculation results are compared with those from the experiment; and the comparison shows that the generalized limit equilibrium method is feasible, simple and accurate.

With the influence of various factors such as geology and engineering etc., the stability of slope engineering is characterized by uncertainness, randomness, fuzziness, and alterableness. Therefore, it is hard to estimate by using simple mechanical and/or mathematic model. It is proposed to solve this problem by using fuzzy-neural network based on Takagi-Sugeno model, which has advantages of neural network and fuzzy logic model. It not only can easily solve the actual engineering problem with fuzziness but also has excellent learning ability. Application results reveal that this model has high accuracy and higher efficiency in convergence compared with the BP neural network model.

Due to many uncertainties in the geotechnical mass, the appreciation of the slope stability is very difficult. On the basis of the conclusion that the uncertainty of the computation parameters is the main factor which influences the reliability of the stability analysis, the fuzzy set theory is used to consider the uncertainty of the computation parameters; and the constitution method of the fuzzy parameters and the idea for analyzing the uncertainty are put forward. By this way, the cut intervals of the safety factor under different membership degrees can be easily calculated according to the corresponding cut intervals of parameters; and the reliability index of the slope stability and the recommended single safety factor can be got. Different examples are studied; and it is shown that this method can fully consider the uncertainty of the computation parameters; and the obtained safety factor is more reasonable and reliable.

The FEM of limiting equilibrium based on Dijkstra algorithm is introduced to the research the long-term stability of rock-slope, and to get the long-term safety factor of the slope. And this method is applied to research the stability of the abutment high-slope at Nuozhadu Hydropower Station. Comparisons between the result by limiting equilibrium method and the result by the FEM of limiting equilibrium method in the elastic-plastic condition, show that this method is credible. The latent sliding surfaces and the safety factor of several time steps are obtained by the FEM of limiting equilibrium method based on Dijkstra algorithm. All of these are based on the stress field of corresponding time steps from visco-elastoplastic FEM result of the abutment high-slope of Nuozhadu Hydropower Station. The stability of the slope is estimated from the above result. And the curve of safety factor vs. time, and long-term safety factor of the slope are also given.

Based on three-dimensional Biot’s consolidation theory, the computer program is developed by FEM to perform the coupled analysis of the groundwater flow and the soil skeleton deformation. The spatial distributions of foundation pit deformation, excess pore water pressure and soil water potential are studied and compared with the corresponding results from two-dimensional analysis. It is demonstrated that the horizontal displacement of the retaining wall and the settlement of the ground surface in the middle section are larger than those in the margin sections due to the spatial effect, whereas excess pore pressure and soil water potential are smaller in the middle section. The results from three-dimensional analysis are compared with those from two-dimensional analysis; and it is shown that the horizontal displacement of the retaining wall and the settlement of the ground surface obtained from two-dimensional analysis are both larger.

In allusion of an engineering case of the improvement of Xiangjiapo cut slope of Yu-Qian highway, this paper firstly describes the sliding of the slope in early stage and unsuccessful controlling works and then it ues the measuring results of ground surface monitor in connexion with detailed geological exploration to judge accuraltely the property and the mechanism of the sliding disater of the cut slope. And on this basis, this paper sums up the reasons of previous unsuccessful improvement and then makes the stability analysis in which the sliding mass and previous supporting works are considered to be a compound body. Finally, the paper draws up a comprehensive multiple-way controlling scheme in which temporary and permanent control of the cut slope are jointed organicly. It is a comprehensive control measure for cut slope sliding, being reliable, rational and economical.

A neural network method based on gray theory is presented, in this method, the influential influence factors on slope stability of flood embankment are analyzed by gray correlation to get the order of each influential factor; then the advantage factors of gray correlation analysis are chosen to train the neural network; and the correlation degrees are taken as a factor to decide the weighted coefficients; finally the trained neural network is used to predict the engineering. This method has been applied to the slope stability analysis of Nanning flood proving slopes. Compared with the actual situation,, this method can satisfy the requirements for slope stability forecast of Nanning flood embankments.

Based on GIS, hazard forecasting of regional landslide hazards is studied; and the hazard zonation map is obtained, which presents the basic information for risk prediction and real-time alarm of landslide hazards. On the platform of MAPGIS software, professional module of information model for landslide hazards spatial forecasting and evaluation is obtained through customized development. By using the module, history and present landslide hazard risk are assessed separately in Yongjia County of Zhejiang Province using the data of history hazards and new hazards happened in 2004 of the county. Therefore ,we can believe that the evaluation model can be tested by history hazard zonation map coupled with new hazards. And it is tested that the new landslide hazards with accurate locations happened during the 3 times of typhoon (Rananim, Haitang and Matsa ) period of 2004 and 2005, which indicates that the evaluation model has great practicality and availability. At the same time, zonation classes obtained by statistic method of history hazards coupled with the method of fast clustering analysis, which conquers the disadvantages in zonation, are more scientific and more objective.

Based on the characteristics of slope geomaterial for in the flood-wall in Nanning city’s ,experimental investigation has been finished in typical bank. The experimental data are used for fitting the volume yield surface and shear yield surface, the constitutive model based on the principle of generalize plasticity is then built . MATLAB is used for numerical simulation; and the rationality of this model is verified by comparing the test curves and theoretical ones.

Qianjiangping landslide, which is located in the left bank of Qinggan river, a branch of Yangzi river, is one new bedding rock landslide induced by impoundment of the Three Gorges Reservoir. The three-dimensional limit equilibrium analysis method is applied to analyze the stability of Qianjiangping landslide and the landslide triggering mechanism. The factors of safety of the landslide under intensive rainfall and reservoir water fluctuation were evaluated. The computation results reflect that the groundwater has an important infection on the stability of Qianjiangping landslide. The reservoir impoundment and intensive rainfall are the dominant exterior factors triggering the landslide.

Soil improvement is an effective method to decrease the endogenous force of soil and retaining structure. Based on elastic foundation beam theory, a finite element model of foundation pit was proposed. The effect of soil improvement on endogenous force of the retaining structure was studied. The results show that the endogenous force reduces with the increase of depth and degree of soil improvement. To save the engineering cost and guarantee the pit safety, it is important to reasonably decide the depth and degree of soil improvement.

The engineering characteristic of left bank B2 debris of jinanqiao hydropower station is studied, especially for the distributing form and distributing characteristic of tuff interlayer.The stability and potential failure form of B2 debris caused by tuff interlayer are also discussed. The stability of B2 debris is analyzed by 2D finite element method and limit equilibrium balance method. The conclusion isdrawn that the safety factor of B2 debris along the bottom of B2 debris can fulfill the engineering reguirement.Furthermore, this paper suggests more study on the characteristic of immersion tuff interlayer and monitoring with feed back analysis in time, are suggested.

Based on the surveys of engineering geology and hydrogeology conditions and analysis of the experimental results of laboratory and field testing, the reason of Chaoyangpo landside is discussed. The investigating results show that the special topography and geology conditions are the main factors of the landside. By analyzing and evaluating of the present landside stability, the comprehensive reinforcing measures are proposed; and good results are obtained. The conclusions of are of referential significance to the similar engineering.

Aiming at the typical geological profile of Fujiapo landslide section of Enshi Gaoping—Jixin section in national Hu—Rong highway, the safety factor of the landslide under saturated state and native state are studied using the strength coefficient reduction method of FEM. It is drawn that the slope under those two conditions is unstable. The results have shown that it is feasible to use the FEM of strength coefficient reduction in the above profile and this method has advantages over others.

Based on the assumption that the normal stress distribution over the slip surface is represented by a Lagrangian interpolation function involving two unknowns, the horizontal and vertical forces and moment equilibrium equations for the sliding body are derived incorporating the effect of anchor forces. Then the analytical solutions of anchor force factors are obtained directly, which satisfy the requirement of the specified factor of safety. This new method for the analysis of anchor reinforced slope overcomes the disadvantage of abrupt change in normal stresses on the slip surface which is encountered when using conventional procedures and the computation process is rather straightforward. This method has been successfully applied to slope stabilization engineering.

The maopingxi rockfill dam with asphalt concrete core is one of the topmost dam with asphalt concrete core in the world. Because the filling materials as changed, the experimental data is very limited, and the parameters for numerical analysis is not nicety, so it is difficult to evaluate the probable state of stress-strain in the dam body. To obtain the parameters of the filling materials, the monitoring data and optimum theory and finite element method are used for back analysis in this paper. Then, the stress and displacement of the dam are computed and analyzed by using the parameters. The results show that the rule and the value of stress-strain by back analysis accord with the monitoring data very wel1.

Based on the study of hydrogeological conditions of dam foundations and permeability characters of Guangzhao RCCD, three dimentional finite element model of seepage calculation are established with considering structures for seepage preventing and drainage system in dam body and foundation. The simulation methods of lamella element and drainage hole curtain are analyzed, and the seepage controlling in different cases are calculated with feasible methods. Through comprehensive analysis of the characteristics of seepage in dam body and foundation , the optimal schemes and reasonable suggestions for seepage controlling are proposed.

The influence of stress path on the stress-strain relationship of sand is illustrated by test information. Stress path characteristics of earth-rock dams are analyzed according to the test information and the results of finite element method. Some calculation methods of earth-rock dam deformation taking stress path into account are introduced afterwards. Finally, well relationship between the stress-strain curves under constant stress ratio and that of variable stress ratio is revealed by analying their test information. The computational method of nonlinear elastic model parameters under variable stress ratio is derived. The deformation analysis method of earth-rock dams considering the influence of stress path is presented.

based on the proposed 3-D elasto-viscoplastic dynamic constitutive model of soil, and considering the dissipation and diffusion of seismic pore water pressure, a 3-D authentic nonlinear method for effective stress dynamic analysis and anti-seismic safety evaluation is presented to study the anti-seismic safety of earth-rock dam on deep riverbed alluviums. Using the proposed method, based on large-scale triaxial dynamic test results of soils, the acceleration and stress response, element anti-seismic safety and slope dynamic stability of one earth-rock dam are studied and evaluated. The study results can provide valuable guide for engineering design.

Based on the use-developed platform of the general-purpose FEM system ABAQUS, Duncan-Chang constitutive model was numerically implemented. Stress and movement analysis for an asphalt concrete core dam including the phases of filling and impounding were conducted by 2-D nonlinear FEM. The magnitudes of stresses and displacements of the dam and asphalt concrete core were obtained. All results are reasonable and capable of providing important reference to the optimization of cross-section zones and design of seepage of asphalt concrete core for the project. Moreover, by fully utilizing the nonlinear analysis capacities provided by ABAQUS, further development is a shortcut and an effective solution to accomplish stress and strain analysis for earth-rock dam.

Dam foundation deformation should be paid more attention in studying foundation failure process. Key node plays an important role in dam foundation deformation analysis. In a 2D-finite element analysis of deep anti-sliding stability of dam section #12 foundation of the Xiangjiaba Project, the problem of key node selection is investigated and a key node selection method is proposed. According to the key node deformation and the distribution of the plastic zone in the foundation, the safety degree of deep anti-sliding stability of foundation of dam section #12 is evaluated on different levels based on the importance of key part which key node belongs to. The safety factor and its lower limit based on the concept of strength reserve of foundation of dam section #12 are given.

The influence of the combined action of powerhouse and dam on sliding stability of gravity dam is a key problem in hydropower projects. In this paper, the problem is analyzed and discussed by means of application of elastic-plastic FEM and calculation of sliding stability safety factor of dam foundation in Jin’an qiao Hydropower Project. The results show that the combined action of powerhouse and dam could effectively improve the sliding stability of superficial dam foundation, but not helpful to the deep dam foundation of Jin’an qiao hydropower station riverbed dam section with the traditional method , overload method and safety factor of strength reserve . Moreover, under the combined action of powerhouse and dam, the maximal compression and tension stress in dam body are decreased effectively to make the stress distribution more uniform. At the same time, the deflection curve of power penstock becomes more smooth to decrease the additional stress caused by the deflection break, which is so as to benefit safe operation of the penstocks.

The soft soil is widespread in Pearl River delta area.There are many problems in reinforcing a dike or constructing a crossing-dyke sluice on soft soil grounds during the construction process, in which the most difficult and key technical problem is the treatment of soft-soil grounds. Several problems that are encountered in construction at present are discussed in this paper, including how to determine reasonably the bearing capacity of soft soil grounds and treat the ground of sluice; how to calculate exactly the settlement of soft soil grounds and control the velocity of filling; parameters selection of soft soil under reinforced dike ; lateral soil pressure; application of the composite foundation and infection of construction sequence on soft soil etc.. The quality and security of project are affected by these problems, which should be solved urgently in present construction works.

The particle breakage has a great influence on the deformations of a rockfill body. Apart from the strength of parent rocks, stress state of rockfill is losely related with the particle breakage degree. Most of the deformations of a high rockfill dam is a reflection of particle breakage under high stress state. Although NHRI’s double yield surface model puts forward by Shen Zhu-jiang (member of CAS) well reflects the deformability of rockfill, the model can not adequately reflect the shear shrinkage induced by particle breakage. So the deformation calculated by NHRI’s model is usually smaller than the real one, and therefore NHRI’s model is only applicable to stress-strain analysis for medium and low rockfill dam. Based on NHRI’s double yield surface model, a numerical analysis method considering strain effects induced by particle breakage is presented in this paper. The method can better reflect the deformability of rockfill. So its calculation result is more reasonable for rockfill dams, especially the high rockfill dam.

The induced condition and mechanical mechanism of hydraulic fracturing is briefly analysed. Based on the triangle fracturing under water pressure and finite element method, an approach is suggested to judge the occurrence of hydraulic fracturing. In this approach it is assumed that there exist local permeable weak planes (cracks) in core; and the plane finite element method (FEM) for hydraulic fracturing analysis is established. The crack is taken as a soft material; and the effect of water pressure acting on both sides of the crack is modeled. By using FEM, the stress of element at the crack tip is obtained; and the possibility of hydraulic fracturing is judged. This approach can also simulate the development of hydraulic fracturing.

Based on the assumption that geogrid and its surrounding soils are a composite material, the effect of reinforcement of dam crest rockfill with geogrids is studied using nonlinear elastic finite element method. The influence of layer number and modulus of geogrids on effect of reinforcement is investigated. The results indicate that reinforcement is helpful in increasing stability and earthquake-resistant ability of dam crest rockfill. It also shows that effect of reinforcement becomes more evident with more layers and large modulus of geogrid.

Wudongde Hydropower Station lies on the Jingsha River, which is located at the upstream of the Yangtze River. The earth rockfill cofferdam is 74m high; the boulder overburden layer of river bed is 70m deep; and the water head difference is 151m. A foundation pit with the depth of 70 m is planned to excavated at the toe of the cofferdam at the downstream side, and concrete wall( 86m high) with geomembrane on the top, the geomembrane has the depth of 43m. The stress and deformation characters of the cofferdam are analyzed by the nonlinear FEM. The processes of construction, the upstream water level,and the excavation in downstream side were modeled. The interface between filling material and the cut-off wall is modeled by Goodman element without thickness. Results of stress and deformation analysis indicate that the design scheme is feasible.Furthermore,the influences of the paramerters of the overburden layer, the influences of filling materials,and the influences of the material, the thickness and the bottom sediment of the cut-off wall are studied. Some suggestions obtained from analysis are presented for the design scheme.

As one of the advanced techniques in concrete-faced rockfill dam (CFRD) construction, concrete extruded curb has shown its advantages at many aspects. ANSYS parametric design language (APDL) is applied to analyzing of CFRD with extruded curb; and the contact between face slab and extruded curb is simulated by ANSYS node-to-surface contact method; especially the nonlinear combination element is set originally to deal with vertical joints and perimeter joints. For a hydropower station, the stress and deformation of dam and concrete face slab are computed respectively in two different cases: with extruded curb and without curb. The different results are compared to analyze the influence of extruded curb on face slab.

Highly plastic clay is usually used to control the cracks produced by the stress concentration around the concrete structure in the rock fill dam. Numerical analysis is preformed on different highly plastic zones in a rock fill dam using the finite elements method. The FEM calculation results have shown that the installation of highly plastic soils on the top of gallery and major diaphram wall can better improve the structural stress of concrete than the full-length installation of the soil along the core bottom. Too large area installation of highly plastic soils in the core bottom will make the originally dispersed loads on the dam body caused by the local installation of soils readjusted, thus increasing the stress of the gallery and the major diaphram wall.

Man has known the wetting deformation of core wall type rockfill dam and paid emphasis on it. However, the wetting deformation of CFRD concrete face rockfill dam is neglected for its water retaining by the upstream face slab. It will bring obvious wetting deformation and affect the face slab’s working condition for the dam body which was filled by the rockfill materials whose wetting deformation are rather large. The computation methods of wetting deformation are proposed to analyse its effects on the stress and deformation of dam body and concrete face slab by FEM based on the wetting deformation experiments of rockfill materials in Tankeng Hydroelectric Station.

The functions of shotcrete and rock bolt support in underground hydrotechnical tunnel construction, such as instable rock mass, flaccid structural plane, wedge-shaped structural plane etc., are introduced. And the application of shotcrete and rock bolt support structure to practical construction is also described briefly.

Mesh and boundany are primary influence factors of calculation procision when the seismic response of embankment dam is analyzed by finite element method. Based on the calculation program developed by the Institute of Geotechnical Engineering in Hohai Univ., the influences of mesh form, mesh size and boundary size on the calculation of seismic response of embankment dam are studied. The results show that mesh holistic form should be horizontally stratified, the upper limit of mesh size is 7 percent to 10 percent of dam height and the calculation area with simple boundary should contain the cover stratum.

According to the seepage control characteristics of acid waste water reservoir dam, the seepage control scheme selecting systems are designed. From six factors of reliability, safety, economy, construction time limit, construction promptness and environmental influence, the authors study deeply these factors so that it forms a two-level measurement system. For the actual seepage control engineering, this paper presents four selecting schemes and uses dualistic factor contrast to calculate the weight of the hard index sign in each factor. A fuzzy mathematical method is used to establish hierarchy evaluation model, and the best scheme of all is found through analyzing and comparing layer by layer. The example shows that multilevel fuzzy comprehensive evaluation model takes on good feasibility and reliability.

Through large scale shear test study on the contact face between the mudcake with different thicknesses and concrete with different roughnesses, various strength and deformation indices have been obtained. The test results show that under the mudcake with the same thickness, the rougher the contact face of concrete, the larger the strength and deformation indices; under the contact face with the same roughness, the thinner the mudcake, the larger the strength and deformation indices. Causes for the above differences among the strength and deformation indices under different test conditions are analyzed. It is appropriate to take into account the existence of mudcake during the tests.

During the dike reinforcement of the Yellow River with silt, cracks appeared in the first project stage in Henan and Shandong Province. There were not quantitative results about impacts of reinforced dike with silt on dike body so it is very difficult to choose the reasonable construction velocity of reinforced dike with silt. In fact, the dissipation course of moisture in silt body and dike is an unsaturated liquid-solid coupling problem. Construction of reinforced dike with silt by steps is a problem of changing water level boundary; and it equivalent to a constant water level boundary with several steps. With unsaturated seepage analysis, saturared line of dike body and silt body can be calculated based on construction of reinforced dike with silt of each step, so the soakage line can be regarded as a known boundary condition. Considering the mechanical characteristics of dike soil and the drainage condition, analysis of unsaturated liquid-solid coupling is carried out; thus the corresponding reasonable construction velocity of reinforced dike with silt can be put forward. Study shows that the analysis results of the method is consistent with the fact; thus it will not only provide theory basis for project design and construction of reinforcing dike with silt in the Yellow River, but also offer references to other rivers’ harnessing.

Type choice of gates is an important work of barrage construction. By computing and analyzing, we obtain the following results: ①comprehensively considering various aspects such as terrain, geology, watercourse and construction etc, an open-flat- bottom barrage with plane gate and stationary hoisting device should be chosen; ② the length of the axis of a barrage should be 626 m. As an open flat barrage, the bottom board elevation is 579.9 m and 29 gate openings will be set up; and the size of each gate openings will be 19×4.1m (width x height).

The potential displacemeter is the gauge for monitoring displacements of embankment and rockfill dams. A brief introduction is given to the function of the potential displacemeter as well as its application in several dam projects. The TS soil displacemeter with single potential displacemeter being the core, applied in many core wall rockfill dams, might be employed to observe the shear displacement or tension displacement between the core wall and the concrete cushion, and deformation of the core wall is monitored in time. The TST face displacemeter with double potential displacemeters being the core is employed to monitor separating deformation and shear deformation of faces so as to provide basis for the determination of treatment schemes and the treatment effectiveness of the separating faces. It has been successfully applied in high concrete face rockfill dams, which gives separating data and variation curves of faces in time. The TSJ joint meter with three potential displacemeters being the core is taken to monitor the opening and shear deformation of joints as well as the settlement deformation in the direction of vertical faces. It has been applied in many concrete face rockfill dams in China and has yielded the deformation and variation curves of joints in time, thus providing basis for the safety evaluation of dams.

End-bearing piles are usually used in sluice foundation of soft soil. The soft soil is aquittard. Therefore seepage prevention is easy to be ignored in foundation design. In fact, the settlement of filled soil often caused undercutting in foundation soil. So as to decrease the safety of sluice and embankment, a reinforcement scheme of fore-interception seepage prevention wall is proposed to solve this problem. Engineering application of this method shows good results in seepage preventing.

The monitor disposing of concrete face rockfill dam Nalan Hydropower Station is introduced. Based on the monitoring data in construction and impounding period for the resent two years, at the deformation and seepage of the dam, stress and strain of the face, and their associative mechanism are analyzed. The construcion quality and stability of the dam after impounding are evaluated. At last, some suggestions are proposed so as to offer reference to similar engineering.

Particle Swarm Optimization（PSO）is introduced in the field of dam monitoring, and then a new dam monitoring model based on PSO Neural Network（PSONN）is put forward. The model makes full use of the global optimization of PSO and local accurate searching of BP Neural Network（BPNN）to provide better initial weights for BPNN. Seriatim PSONN（SPSONN）model, Whole PSONN（WPSONN）model, Seriatim BPNN（SBPNN）model and Whole BPNN（WBPNN）model are compared here, the results show that the seriatim prediction models are superior to those whole models with higher forecast precision. Furthermore, the PSONN models exhibit faster convergence rate, less iterative number and better forecast precision than the BPNN ones. Especially, the SPSONN model is more efficient to satisfy the demand of real-time prediction of dam monitoring.

Floods in Xinjiang are characterized by steep rising and falling, high content of silt, sudden strong flood etc. Alluvial river bed has a bigger profile grade while keeping balance of scouring and aggregation in the upstream and in the middle stream. The problem of scouring to flood control works is obvious during flooding periods. Profile grade in the middle stream and downstream become small while rivers bed frequent swings and shifts. Unbalanced sand moving from longitudinal section and cross section have caused river situation to be changed, river bed to scoure, thus resulting in outburst of river banks and flood disease. By analyzing the characteristics of rivers and river bed in Xinjiang, hydrologic factors, river bed development, river scouring and aggravation based on the characteristics of rivers in Xinjiang and local flood control practice, the paper provides approach of river treatment and layout methods of flood control works and discusses selection of designing factors of different parts of flood control works, structure types of flood control buildings.

In a pumped-storage power station of Jiangsu province, the concrete face rockfill dam is constructed in the upper reservoir. Because it is a great amount of excavation of impervious panel foundation, and most excavated materials are strongly weathered silty mudstone and argillaceous siltstone, it is of great significance to partly utilize excavated materials of strong weathered as embankment materials of the main dam for the purpose of reaching the balance between excavating and filling, protecting the environment, reducing abandoned materials and increasing economic benefit. Experimental study on the rock physical properties, compression strength, compressing distortion, mineral composition analysis and chemical analysis, etc., were carried out for strongly weathered rocks. And the results of experiment on wet and dry characteristics of the rock, physical mechanical characteristics of circulation fatigue due to different temperatures, were obtained the variation law of rocks under the changed conditions of wet and dry cases, as well as different temperatures. The whole study provides the scientific basis for the utilization of strongly weathered rock and the prediction of their long-term stability.

The index of Rock Mass Integrity (IRMI) is a new method of evaluating the rock quality based on borehole imaging, which is defined as IRMR = I / (I + F), where I means the characteristics of integrity and F means the fracturing of rock mass. The borehole imaging has been proved to be successful and effective, and provided a lot of first-hand geological data in Tsingtao Bay Bridge. Through the comparison with other evaluating method of rock quality, the conclusions are drawn as:( 1) the digital borehole camera system overcomes the shortcomings of the conventional borehole logging method; (2) the digital borehole camera system provides a viable method to evaluate IRMI; (3) IRMI can accurately reflect the structural features of the rock mass;( 4) IRMI is usually higher than rock quality designation (RQD).

Binocular stereo vision system and digital image correlation method are combined to measure3-D displacement of soil surface on wet jet pile composite foundation modal. The calibrated projection matrixes are determined. A novel method for extracting corner coordinates and a searching method for correlating the corresponding points of two cameras based on affine transformation are presented. 3-D displacement-load curves are obtained. The experimental results demonstrate that it is a valuable attempt to measure the surface displacement of soil on wet jet pile composite foundation modal using this system, and provides an efficient tool for the measuring of 3-D displacement of soil surface.

Grain crushing is a basic behavior of rockfills. It affects the strain and strength characteristics of rockfills significantly. For high rockfill dams, the rockfill grains will be crushed largely because of large confining pressure. The grain crushing may increase the deformation rate of rockfill dams. To understand the behavior and mechanism of rockfill dams, the behavoirs of rockfill grain crushing were researched. By use of large-size triaxial tests the quantity of rockfill grain crushing was studied. The influence factors such as density, gradation and rock strength were investigated. The relationship between grain crushing and stresses acted on the rockfills was studied. The model to calculate the quntity of grain crushing rate and the relations of strains caused by grain crushing with grain crushing rate were proposed.

Shallow biogenetic gassy sand soil is one of special unsaturated soil. The biogenetic gas with different quantities constained in the sand soil has great influence on its engineering properties. In this paper, the preliminary judgment is drawn on the existence of the biogenetic gas in the fluvial-lacustrine deposit sand soil, and then the in-situ and laboratory tests are done to compare the bearing capacities of the soil before and after gas release. It is found that without seepage failure, the slow release of the biogenetic gas can increase the bearing capacity of the soil, which is benefit to the stability of the upper buildings.

Sand usually exists in natural soft soil, especially in silt or mucky soil in the delta. The systematic investigation into the effect of sand content on the strength of sandy soil-cement mixed with silt or mucky soil can directly provide useful data for the design and construction of soil-cement mixing piles. The typical silt and mucky soil were drilled from two places in the Delta of the Pearl River. The fine sands with different contents were added to the soil samples with natural water content to make the samples of sandy soil-cement. The samples of sandy soil-cement were then cured for different ages, for the measurement of unconfined compression strength. Therefore, the variation laws of the strength of sandy soil-cement with sand content and other influence factors were obtained, thus coming to the conclusions and the unconfined compression strength of the sandy soil-cement obviously increases because sand exists as a role of fine aggregate, that the unconfined compression strength of the sandy soil-cement with 0.02 to 0.25 in sand content is 0.25 to 0.60 times higher than that of soil-cement without sand; and the formula for estimating the unconfined compression strength of sandy soil-cement was obtained by considering the influence factors including sand content, mass ratio of water to soil particle, mass ratio of cement to soil particle and the practical mass ratio of water to cement.

Consolidated undrained triaxial shear tests were conducted to investigate the behaviors of cement solidified dredged material (DM); the failure type and shear strength parameters were studied. Test results show that the stress-strain curves change from ideal elastoplasticity to strain softening with cement content increase. When cement content is 50 kg/m3, the stress-strain curves have three types with cell pressure increasing, namely, perfect elastoplasticity type, strain softening type and strain hardening type. When cement content is higher than 100 kg/m3, all the samples present brittle property. When DM is treated by cement, it becomes a kind of structured soil. When cell pressure is lower than sample structural strength, it has little influence on the compressive strength. The effective cohesion increases much with increase of cement content, while effective internal friction angle lies between 32 and 43 degree, indicating that the effect of cement solidification acts mainly on the bonding force among soil particles, and the filling effect is weak.

The strain comprehensive structure potential (strain-CSP) is a new structural parameter of soils and it can be applied to complex stress condition conveniently. Based on the definition of strain-CSP, the structural parameter curves of intact loess or men-made structural loess are obtained using the data of stress-strain curves obtained from triaxial tests on intact loess (or men-made structural loess)，disturbed loess and saturated loess, and structural variation properties of unsaturated loess are analyzed under triaxial complex stress conditions. The results have shown that the strain-CSP as a new structural parameter of soils, its changing trend relative to a certain affecting factor is the same as that of the stress comprehensive structure potential. Using this new structural parameter of soils, the fundamental features of soils structural parameter curves under triaxial complex stress condition can be explained reasonably, and the variation and development of soils structural characteristics in 3-D complex stress state can be described suitably.

Based on a large amount of laboratory and field experiments, and the excavation modeling experiment, through the analysis of the genesis, texture and structure of drifted material formed in different period, the engineering geologic conditions of forming hole in deep drified material are studied; and the physico-mechanaical parameters are achieved precisely. A wide span hole in deep drifted material has been successfully excavated at Xilongchi Pumped Storage Power Station. And the experimental excavation, observation and analysis are done to know whether the hole can be formed in the drifted material formed in the first period; and a lot of experiments in lab. and infield also are done. Finally, the physico-mechanical parameters of drifted material are achieved precisely. Through careful design and careful construction, it is successfal to dig big span hole in the deep drifted material.

Recently, geosynthetic clay liners (GCL) have been more and more used in different anti-seepage engineering projects; and bentonite’s microstructure in GCLs after hydration has great influences on its long-term hydraulic properties and mechanical characteristics. Based on quantitative analysis of bentonite’s microstructure in GCLs after hydration, the influence of liquids is discussed and the mechanism of the influence is revealed by chemical analysis of liquids. The results show that: ①when the hydration liquid is landfill leachate, the pore volume density of bentonite is the biggest, and the ratio of large pores is the highest; ②the reasons of the above rule lie in two aspects. On one hand, thickness of montmorillonite surface double-layer is the smallest because of high cation concentration in landfill leachate. On the other hand, the ratio of large cations on montmorillonite surface is the highest because of more frequent cation exchange.

To evaluate the temperature stress of HDPE sheet, a simple evaluation formula of temperature stress is proposed. The relationship between temperature and elastic modulus or coefficient of temperature expansion is investigated by experiment; and the temperature stress is obtained by loadcell, thermocouple, and displacement gauge. The results show that the temperature stress within the HDPE sheet decreased rapidly with the decrease of temperature. The temperature stress evaluated by the proposed method, is very close to the experimental value.

The geological phenomena of the long distance water diversion project in Xinjiang are very abundant and complicated. In different areas, the engineering geological phenomena and geological bodies have unique quality and character. In order to satisfy the requirement of project construction, thoroughgoing and painstaking investigation of geological phenomena is necessary. Beside the normal geological problems in the water diversion works of south bank of the Wulonggu River, such as soft rock tunnel, soft foundation under the dam of “500” reservoir and desert sand of the aqueduct have been investigated; and the huge water diversion works system has been constructed and running well now. However, the other problems need to be studied and confirmed further in the future running of this system.

A wedge loading compact tension(WLCT) system was used in this study to investigate the phenomenon of crack propagation in rock slabs. The rock slabs under investigation were selected from natural building stones. A high-resolution crack-strain-gage system was used to measure the fractal crack propagation velocity. The proposed experimental procedure is able to determine the crack velocity, fractal dimension and fracture toughness of the test specimen. This study finds: the steady-state crack velocity near the crack tip is measured in the range of 0.113 to 313.043 cm/s; the unstable crack velocity near the crack tip is measured in the range of 0.094 to 2 489.816 cm/s; the subcritical fractal dimension is found to be 0.994 3 to 1.036 6; the initial fracture toughness is found to be 1.891 5 to 3.500 1 MPa?m1/2; the fractal subcritical fracture toughness is found to be 2.063 6 to 3.712 8 MPa?m1/2.

The porosity of coarse-grained soils relates closely other phsical mechanical parameters. On the basis of summarizing and analysing a great number of previous testing data, this paper plays a stress on the porosity of coarse-grained soils to study its correlatability with other physico-mechanical parameters using such methods as graphic representation, calculation and analysis and finally finds that there exists a positive or negative correlativity between the porosity and other indexe. To know this correlatability is clearly of paramount signifcane to controlling porosity effectively, analysing and pvedicting test parameters and rational selection of the parameters for researchers, engineers and workers in their tests, design and construction process.

Data organization and management of 3D urban geological data is a critical point in the construction of 3D Urban Geological Information System. Based on the analysis of the data types, data formats and user’s requirements, a novel conception of two-tier and four-sort data for 3D urban geological information is developed. Two-tier data means that the original data and the interpreted data can be distinguished from 3D urban geological database. Four-sort data means that the geological database has a four-sort constitution consisting of: geographical data, original investigation data, professional interpreted data and 3D geological modeling data. To meet the demand of the technologist with the different majors, several professional databases are constructed from 3D urban geological data. To realize such functions as 3D visual analysis of geological data, 3D geological modeling data is provided specially. These approaches have been applied successfully in the management and service system of 3D urban geological data in Beijing and Shanghai cities.

Monitoring is one of the important bases for dynamic design and information construction in underground project, and the analysis and reporting of monitoring information are even more important, if they are all-sided, accuracy and timely. The excavation of underground powerhouse of Pengshui project in Wujiang River faces many problems, such as large-scale span and height, complex geological conditions, long period, the disturbance of construction, etc. In order to ensure safety of construction and operation, many monitoring instruments were installed in underground powerhouse, which were used to monitor the deformation and stability of surrounding rockmass in construction. The analysis of monitoring results indicate: the surrounding rockmass of underground powerhouse is stable in general; design supports can enhance the self-stability of rockmass and ensure the stability of underground powerhouse; however, the stability of some local rock masses, especially the shale in the downstream sidewall are bad due to geological condition and rockmass blasting.

Ground-based 3D laser scanning is a relatively new data collection and analysis technique, which can scan the object quickly and acquire the high resolution, high density 3D coordinates of points. The 3D laser scanning technology and the principle of new scanning are introduced; and the main 3D scanning equipments are compared. 3D laser scanning technique can be applied to slope stability monitoring and rock fracture faces survey. Compared with the technology of traditional geotechnical monitor and geology survey, the 3D laser scanning technique has the advantages of high accuracy, high speed and low cost of human resources; and it has great potential for future application.

Prefabricated vertical drains (PVD) are usually used for reinforcement and dewatering of soft clay foundation. According to the combining manner of the core board and filter, PVD can be divided into two types as separate shape PVD and integral shape PVD. A series of tests were carried out to compare the difference of the two types of PVD in physical property, mechanical property and hydraulic property. The results indicate that comparing to separate shape PVD, the integral shape PVD has higher tensile strength, better ductility, higher rigidity and better discharge capacity.

Based on dynamic triaxial tests, the dynamic elastic modulus of cemented silt-silt composite sample is studied with the influences of confining pressure, replacement ratio and initial dry density. The results show that the dynamic modulus of composite sample is much higher than that of pure silt. The relationship of dynamic elastic modulus versus strain is similar to that of pure silt. The dynamic elastic modulus of cemented silt-silt composite sample decreases with strain increasing. At the same strain level, the elastic modulus increases as the confining pressure, the replacement ratio, and the initial dry density increase. The influence of replacement ratio, confining pressure, and the initial dry density on modulus is significant at low confining pressure. The maximum dynamic modulus of composite sample increases as the confining pressure, the replacement ratio, and the initial dry density increase. The curves exist within a narrow area.

The characteristics of soil and water and shear strength of Yellow River dyke’s unsaturated soil under different confining pressures are studied by using special triaxial apparatus to simulate the real condition exposed on unsaturated soil in engineering. Based on the water-soil curves, it is easy to draw that the matric suction decreases with the increasing of surrounding pressure and water content; the effective friction angle changes little with the changing of water content; but the total cohesion changes greatly. The soil has bigger suction and total cohesion at lower water content. Based on the test results, the model of shear strength of unsaturated soil is presented with clear parameters. The fitting error is small and meets the calculation requirement of shear strength of unsaturated soil.

Vacuum-surcharge preloading is an economical and reasonable method for reinforcing the deep soft foundation. Improper construction practice will result in bad effect during the process of vacuum-surcharge preloading. So it is necessary to strengthen monitoring of the effect and safety of soft deep foundation reinforcement during all the construction time. A certain project with soft foundation treatment by vacuum-surcharge preloading is described in detail. The methods of construction and monitoring can be for reference to other projects.

As a mixture of soil and rock medium, coarse-grained soil has the inherent unique nature of inhomogeneity, discontinuity and difficulty of sampling, so as to bring about great difficulty in study. Coarse-grained soil is a typical porous medium, and its permeability is closely related to the content of gravel. Using home-built constant head permeameter, we mensured the permeability coefficient of coarse-grained soil of different gravel contents, and found that there exists index relationship between them. Changing gravel content rationally is a feasible method to control the permeability of coarse-grained soil in engineering. An empirical formula for calculating the composite permeability coefficient of soil and rock mixture is put forward based on power averaging method; and the formula is verified by the experimental results; and it provides a concise and useful computational tool for the theoretical calculation of coarse-grained soil permeability coefficient.

Based on the pullout test of angle steel inserted foundation,the bond performance and stress distribution between the angle steel and concrete are discussed. The influence on the pullout failure of inserted foundation is analyzed. The variation law of coefficient of friction of inserted foundation is emphatically investigated; and the average friction coefficient which is up to pratice and design is presented.

The Menard pressuremeter (GA) is described in teens of its basic structures, operating principle and testing with relevant calculating methods, and the application and the analysis to the in-sutu measurement of the foundation engineering for sandy gravel., The results of the pressuremeter test are annlysed so as to determine the bearing capacity and deformation coordinates of sandy gravel subgrade, which in compared to the results of laboratory tests and extra heavy dynamic penetration tests. It is proved that the results obtained in this paper can be used for engineering design and references for similar project.

The error analysis of checking tests for nonwoven geotextile is performed. The system error of various characteristic indexes are presented using the statistical method, then the reliability of test results is analyzed.

The tangential modulus is a very important mechanical parameter for the incremental constitutive model, so the research on its law has great significance. The initial elastic modulus has been studied at first. The relations among the initial tangential modulus, the confining pressure, over-consolidation ratio and the initial void ratio are deduced. The triaxial compression test of clay taken from a certain area in Hangzhou is used as verification.

Soil arching effect is very important to the soil pressure calculations. The problem of the sand arching effect was studied through the indoors baffle drop test designed by the authors. Along with the baffle’s drop, the sand’s weight on the baffle, the sand’s stress and the lateral pressure coefficient that under different buried depths of sand in the box were characterized. It is shown that the sand’s weight on the baffle reduces quickly when the baffle has a small displacement. The sand’s weight on the baffle reduces slowly when the baffle drops gradually. We consider that the sand reaches the critical state when the baffle’s displacement is 2.5mm. While the baffle drops, the vertical soil pressure reduces in the central line on the top of the baffle and the vertical soil pressure increases in the line on the top of the baffle’s sides. Lateral pressure coefficients in the central line on the top of the baffle increase obviously. Finally, the formation mechanism of the sand arching effect was analyzed through the stress variety regularities in the sand.

Different scales of gulches were found in Baoquan Upper Reservoir during the excavation. The coverages of the gulches are mainly debris soil of less compressibility, but deformation modulus is only about 0.001 compared to rocky foundation. The main issues of the gulch treatment considering the anti-seepage by using asphalt and concrete for of the upper reservoir bank and avoiding large heterogeneous settlement of the contact zone in soft and hard rock, are analyzed and estimated in detail.

The express communication between Yu-zhong peninsula, Jiangbei District and Nanan District will be established by the submarine tunnel of Chaotianmen in Chongqing. The determination of the cover thickness of the submarine tunnel is very important, because it will be very dangerous if the cover thickness is too small; whereas the length, slope gradient and cost will be increased if a larger cover thickness is chosen. The reasonable cover thickness for submarine Tunnel of Chaotianmen in Chongqing is determined by engineering analogism and numerical simulation.

Water Transfer Project across the Yellow River is located at the area measuring at 7 grade of Richter scale. At the northern flood plain of the Yellow River, the water canal will be established on a thick sand ground. The liquefaction prevention of sand under earthquake is a key technical problem taken into account in design. To estimate the possible liquefaction depth of the foundation and to find an optimal reinforcement measure, large amount of field standard penetration tests, dynamic triaxial tests and dynamic numerical analysis were performed. The work of tests and numerical analytical and main conclusions are introduced in this paper.

The liquefied embankment foundation of a reservoir is simulated by using FLAC 3D software; the reinforcing effect of the high pressure circular jet grouting diaphragm wall is estimated; the reliability and reasonableness of the reinforcing scheme through high pressure circular jet grouting diaphragm wall are verified. From the analysis there is trend of liquefaction in the embankment foundation, and lateral deformation will occur in soil; therefore it is necessary to reinforce the embankment foundation. The high pressure circular jet grouting diaphragm wall is suitable for reinforcing the constructed reservoir, safety of the reservoir can also be guaranteed because stress and deformation of the liquefied embankment foundation are in the permittable limit. Technical information can be provided for maintaining and reinforcing the constructed hydraulic projects.

The finite element analysis procedure PLAXIS was presented to predict the dynamic response of macadam subgrade under dynamic loading. The deformation and acceleration of the subgrade were calculated to obtain the dynamic characters. Compared with the traditional soil subgrade, the macadam subgrade has larger compressive strength and better deformation recoverability. The finite element analysis was performed to prove the feasibility to use crushed stones to construct subgrade on the area with little soil resource.

Hydraulic fracturing is one of the important affecting factors in water inflow out of deep-buried tunnel construction. Its failure mechanism is a hot topic in geotechnical engineering fields. Based on stress states in rock fracture surface and fracture mechanics, fracture propagating models comprise tension-shear and compression-shear mixed fracturing. Using crack propagation criterion for mixed fracture model, calculation formulae of critical internal water pressure of two kinds of failure models are obtained respectively; and the affecting laws of fracture location and direction are studied. This study shows that fracture is most easily to propagate when it is parallel to the direction of maximal in-situ stress under tension-shear mixed model. For compression-shear mixed model, fracture is most easily to propagate when the angle between of fracture direction and maximal in-situ stress is within range of 30°and 75°.

In order to study on primary parametric resonance with primary resonance of thin rectangular plate on Winkler foundation subjected to harmonic excitation considering material nonlinearity, its nonlinear dynamical equation is established and transformed to nonlinear vibration equation based on Galerkin’s method. By using the method of multiple scales for nonlinear vibration, the approximate solution of primary parametric resonance and primary resonance of the system is acquired. Numerical computation is carried out to analyze the influences of excitation, detuning, damping, nonlinear parameters and geometric parameters on the system.

Laboratory test has been done by using the dynamic triaxial test machine in order to study the damage evolution of frozen aeolian soil in the west of Liaoning Province under dynamic loading. The constitutive relation and damage evolution formula of frozen soil are established, and the dynamic evolution curve between damage variable and strain is sketched. At the same time, pertaining to the at initial stage of damage of frozen aeolian soil, the microstructure is observed by using the scanning electronic microscope (SEM). The results show that the process of damage of frozen aeolian soil can be divided into three stages. In plastic damage stage, the speed of damage growth is fast, and the increase of damage variable is non-linear. In micro-crack damage stage, the damage growth is relatively flat and smooth, and the relation between damage variable and strain is approximately linear. The interior micro-cracks appear in the middle of sample. From the middle to the ends of in the sample, the micro-cracks are in the from of circular growth. Through transfixion and collection of cracks, the inclined cracks come into being and enlarge step by step.

The layer of parallel isolation structure is combined with sliding isolated bearings and rubber bearings. With the rubber bearings and the sliding isolation bearings learning from other’s strong points to offset their weakness, the parallel isolation structure is an economic system. Because the vertical stiffness of two kinds of bearings in parallel isolation structure is different, their axial forces will shift each other when the displacement of isolation layer increases under earthquake. The transfer is a self-adjustable performance of the system ,and this redistribution of axial forces is favorable to the whole system. And can make the system change its energy dissipation capacity. A according to reasonable hypothesis, the axial forces-displacement behavior of the sliding isolated bearings is deduced and the shape of their relation curve is papilionaceous, when the transfer force is considered.

The layer characteristics and the difference of electromagnetic properties of the section of the blasting compaction for filling stone have the basic physical testing precondition of ground penetrating radar (GPR). The testing practice of a beach dike in Dongtou of Zhejiang Province, shows that the bottom depth, width, the waist width etc.of the deep thick ripped rock layer, whose bottom depth reaches 35m, can be tested using GPR when the 16MHz lower frequency antenna and the appropriate testing parameters are used. But it is difficult to recognize the mixing layer of soil and stone in the bottom.

For analyzing the dynamical stability of deck rectangular thin plate subject to harmonic excitation in temperature field, the system nonlinear dynamical equation is established based on elastic theory, and is transformed to nonlinear vibration equation based on Galerkin’s method. The stability system is analyzed by means of stability theory. By using the multiple scales method of nonlinear vibration, the approximation solution of system primary resonance is acquired. The analysis results show that the system primary resonance curve has jumping phenomenon and hard stiffness characteristic.

In order to evaluate the inner explosion effect of sectional tunnel in subway in Nanjing, the engineering situation of inner explosion of 10 kg TNT with 1.1 m distance from tunnel bottom is numerically simulated with LS-DYNA3D.The keyword of simulation of air blast due to conventional weapon avoids complex and trivial Euler calculation and ALE coupling analysis, so as to simplify model construction. The history of displacements and velocities of different nodes were obtained, the history of acceleration of elements and their maximum principal strain were obtained as well. The result that the sectional tunnel in subway is safe with inner explosion of 10 kg TNT.

In soft soil, the underground tunnel excavation often induces ground deformation. Due to city underground excavation tunnel lies in area with dense and intensive buildings, the damage of the soil deformation to around structures is noticeable. On the other side, the construction of adjacent buildings will cause loading and deformation to the existing tunnel inevitably. This article mainly elaborate the research achievements about the influence of soil deformation caused by underground excavation on the buildings, the pile foundation, the underground utilities, the existing tunnel, the foundation pit, and the influence of the adjacent structure construction on the exiting tunnel. The future direction and method of this study are also proposed.

City construction is strengthened, foundation soil structure and properties change, and the predominant period and the vibration property of foundation soil alter in city region. If ground soil predominant period and structure natural period are close to each other, they can produce resonance destruction, resulting in many unusual phenomena that can not be explained with universal knowledge in the earthquake. Structure natural period is usually "definite value", but predominant period which may be "variable" is often neglected. The main reason of predominant period change comes from the effect of geological body or the site soil and the changes of border condition. Many aspects of urban construction, such as development of the underground space of large yardstick in the city , establishment of a large number of piles, especially even overlength piles, the enclose and protect of large deep foundation pit, application of deep and big foundation, reinforcement and treatment of the weak soil ground, the drawing and polluting of groundwater, the additional stress of the geological body induced by; topographical change and city unique environmental effect etc.; will change the structure of site soil and the properties of foundation soil; accordingly change the classification of the place partially or wholly, will influence the characteristics of the covering soil layer and the parameters like shear wave velocity; consequently the predominant period of foundation soil will change. Therefore, in aseismic design it is necessary to comprehensively consider the effect of the variation of site category which changes with site boundary conditions before and after construction, on the aseismic features of buildings.

The coalescence mechanism of coplanar intermittent flaws under static and dynamic loading is important in determining the position and shear strength of sliding face of rock slope. The process of the fracture propagation and coalescence between two coplanar intermittent flaws is studied under uniaxial static and dynamic loading. The specimens made of sandstone-like modeling material contain two pre-existing coplanar flaws with different flaw angles from 0o to 90o. The result indicates that the coalescence modes are different for different flaw angles. When the flaw angles are between 0o and 35o, the flaw surfaces produce close deformation mostly; when the flaw angles are between 45o and 65o, the fractures coalesce in shear modes; when the flaw angles are between 75o and 90o, the splitting failures are prone to appear. Moreover, the growth of the wing fracture and secondary co-planar fracture tends to the original propagation direction, and the immediate coalescence is taken place easily between two pre-existing flaws. But the fracture coalescence path is winding under static loading, which is different from dynamic loading. Additionally, the lowest strength is observed when the flaw angle is 35o for specimens containing intermittent flaws, which is different from specimens containing persistent flaws whose lowest strength is observed at 60o. The reason is that the strength of fracture surface is not mobilized when the specimen fails. Because the rock bridge’s strength and fracture surface’s friction can’t be mobilized simultaneously, the shear strength formula for rock mass containing intermittent flaws should introduce a strength mobilization factor.

This paper gives an analysis of blasting vibration influence of a traversing diversion tunnel construction on the above existing railway tunnel, by using numerical methods and field test , associated with the practical situation of Shoupayan Tunnel of Nei-Kun Railway which was traversed by the diversion tunnel of Baishuijiang Cascade Ⅲ Hydropower Station in Yanjin Yunnan Province. The analysis result indicates that, empirical formula’s results are safe and feasible. Numerical simulation results are more contiguous with engineering practice than those of empirical formula. When the distance between diversion tunnel face and railway tunnel is less than 4D (D is the hydraulic tunnel diameter), the vibration speeds at the point of intersection in railway tunnel must be monitored, especially for the vertical vibration speed. When constructing the diversion tunnel under the railway tunnel, the detonator of the maximum segment should be less than 2.5kg in order to satisfy control criterion of vibration speed. The blasting vibration monitoring in the course of excavation and the blasting parameters modification timely according to monitoring results are the guarantees for the successfully nearby excavation.

There are some problems such as plane-section assumption and three dimensional effects in dynamic testing on cast-in-situ concrete thin-wall pipe pile with large diameter. The plane-section assumption is not always satisfied in low strain dynamic testing of pipe pile without cap, because the nonaxisymmetric bending mode is excitated. The measuring point on top of pile at angle of ninety degree will suffer less high-frequency interference. So, the reflected wave signal is distinct and clear at this point. Both analytical and numerical results indicate that the reflection peak from pile bottom and defect is obvious at the top of pile with cap. The high-frequency interference at different points with different distance from the center of cap pile has the same frequency but different velocity amplitude. The point with distance 0.5k from the center of cap pile surfers minimum interference.

The finite element software of ANSYS is employed to analyze the influence of rock crack length and type, different diameters of explosive, pre-split blasting and smooth blasting on dynamic stress intensity factors of crack-tip. The results indicate that the pre-split slot is extended mainly from the crack at the blasting hole under the blasting shock wave and detonation gas loading; with the increase of the diameter ratio of explosive to blasting hole, the dynamic stress intensity factor increases; but the curve form of dynamic stress intensity factor keeps unchangeable; the later peak value of smooth blasting is greater than that of pre-split basting because of the existence of free face.

Based on the characteristic of vehicle load and the actual situation of over loading of vehicles in China, the quasi-static method that simplify vehicle load as static concentrated load is adopted to analyze the influence of embankment height on expressway settlement of soft ground induced by vehicle load through four engineering examples. The results indicate that the settlement of expressway on soft ground induced by vehicle loads exponentially increases with the decrease of embankment height; and increasing the embankment height is an effective method to reduce the settlement. An optimal embankment height may exist in a range of embankment height. If the embankment height is lower or higher than that optimal one, the highway settlement induced by vehicle load will increase. Whether this optimal height exists or not and its actual value are related to the vehicle load and the soil character.

A DDS-70 dynamic triaxial apparatus is used to investigate the elastic modulus of reinforced soil. The influences of confining pressure, compactness and the reinforcing patterns on the elastic modulus are studied. The results show that the relationship of dynamic stress versus dynamic strain of reinforced soil tally with hyperbolic model. The curves of dynamic elastic modulus versus strain for reinforced soil are similar to that of pure soil. For reinforced soil sample the dynamic elastic modulus decreases with strain increasing; at the same dynamic stress level, the dynamic elastic modulus increases with the confining pressure and the initial dry density increasing and decreases with dynamic strain increasing; the relationship between modulus and strain is exponential decay. The maximum dynamic elastic modulus relates with reinforce material, confining pressure, and compactness of the soil.

The displacement from back analysis has been extensively applied to underground projects because it can be measured conveniently, accurately and economically. A dynamic multi-step finite element model is established to simulate the excavation process of Laxiwa underground power-house using the large software FINAL which is introduced from Austria. The data of incremental displacement during the third layer’s excavation are applied to back analysis with the established finite element model to calculate parameters of initial geostress and elastic modulus. Finally, the results of back analysis are used to predict the stability of surrounding rocks during the later excavation. The comparison between computed and measured incremental displacements show a good coincidence, so as to prove the feasibility of the method.

The collapsibility of loess, which can be effectively eliminated by the dynamic compaction, does great harm to the safety of constructions. The effect of the dynamic compaction is evaluated through the contrast and analysis of the physical and mechanical properties of the collapsible loess before and after dynamic compacting. The compacting effect can be divided into three phases along the depth, and the most effective improved depth is from 3 to 8 m. The content of pores larger than 20 μm decreases and the content of pores smaller than 5 μm increases after the dynamic compaction. The density of loess is improved.

The working out section refers to the cavity where the mines in this area has been excavated.Up to now, a few of studies about constructing expressway above the ground of old shallow workingout section have been implemented. And the analysis of the suitability of engineering geology, quality control and construction technology has great significance for this special engineering. Combining with the practice of Changde-Jishou expressway, the treatment technology of dynamic compacting replacement for old shallow workingout section includes the requirement of design and treatment, treatment scope, project selection and in-situ test analysis of dynamic compacting replacement which are analyzed and evaluated carefully. Therefore, the construction organization design for constructing expressway above the old-shallow march is raised in this paper. The findings indicate that the dynamic compacting replacement for this kind of engineering is reliable.

The construction method of earth pressure balanced shield has become the one of main trend for underground tunnel construction in metropolis. The torque on cutter head is by far higher than the one of Mud-water Pressure-adding Balance Shield, which is a common concern in the field of shield tunnel engineering. At present, the method of empirical estimation for torque of cutter head is adopted mostly, unfortunately, this method has a too wide estimation interval. For lack of experiences in construction and in consideration of construction safty, man cannot but use the ultimate value of torque to make the design of the assebling torque of shield, thus resulting in great waste in cost. According to the mechanism of torque formation, this paper studies the method to calculate the torques of every composition members respectively and then establish a model for the calculation of the torque on shield machine’s cutter head. Finally, the paper verifies the rationality of the model through an engineering case of shield construction in a subway project..

Based onradical-basis function network theory the prediction of long-term surface settlement above the tunnel axes caused by shield construction is programmed with Matlab software. In actual operation, training (fitness) and simulating (prediction) are combined to make the prediction results more precise. 6 case studies show that, the ground long-term settlement can be predicted accurately by the radical-basis function network.

A landslide occurred during strengthening the major dam of a reservoir in Yunnan Province.This paper analyzes the reasons of landslide from the aspects of deign, construction and management, and introduces the corresponding measures. Some conclusions are drawn so as to provide reference for other projects.

In this paper the outrush accidents during construction period of a hydroplant’s diversion tunnels and their main characteristics are introduced in brief. Then the reasons of outrush accidents are analyzed based on rock mass structure and hydrogeological conditions. At last the outrush scopes are forecasted simply according to the outrush data and surrounding rock mass geological conditions.

Based on frequence-dependent stiffness and damp coefficients, the Beam-on-Dynamic-Winkler-Foundation is adopted to obtain the horizontal dynamic response of a single pile with attached mass at pile tip.Through the solution, the influence of many parameters on the dynamic response of pile, such as the ratio of Young’s modulus of pile to that of soil, the ratio of pile length to diameter and the excitation frequency, is studied. It is found that, the dynamic response will decrease when considering the attached mass, but the influence of the excitation frequency is more remarkable.

Finite element method is applied to calculate nonlinear dynamic responses of underground structure and the data of dynamic responses of structure are available. The structure is consists of steel shell and soil body. The elastic-plastic constitutive model is used to modeling deformation characteristic of soil body and steel shell. Drucker-Prager and Mohr-Coulomb yield criteria are applied to describe the soil body and the steel shell, respectively. The blasting load is determined according to experimental data of air explosion. Calculating results using finite element method show that it is effective to calculate dynamic responses of underground structure acted by blasting loads and the proposed defense structure is safety against explosion loads.

Monitoring of Jiuhuashan Mountain tunnel’s deep foundation pit construction involves inside bracing stress, horizontal movement ,settlement and groundwater table ect. The construction follows the information measures , forecasts and deals with emergency in time on the basis of monitoring data .This monitoring work ensures the safety and smooth completion of the project .Valuable experiences are obtained gained for foundation pit information construction.

As a new kind of composite pile for the soft soil foundation treatment, concrete-cored DCM pile is composed of two parts: the inner precast concrete pile and the external DCM pile socket. Load transfer mechanism of concrete-cored DCM pile is studied with in-situ test method and elasto-plastic finite element method. The results show that the upper load is carried by the inner concrete-core, external DCM pile and surrounding soil of pile, while the inner concrete-core is the main. Lateral friction resistance between pile and soil decreases with depth increasing, and the lateral friction resistance between concrete-core and external DCM pile has a shape of “S” with depth increasing. Load-bearing characteristic of concrete-cored DCM pile is similar with rigid pile and different with flexibility pile, and the concrete-cored DCM pile can be regarded as pure friction pile.

Finite element method (FEM) has been widely used in geotechnical engineering, but relatively less in the analysis of laterally loaded piles. Few literatures about the numerical method simulating the loading capacity and deformation of laterally loaded piles-soils structure have been reported. The main purpose of this paper is to study the lateral deformation of laterally loaded piles by using FEM. First, The basic theories and methods of the laterally loaded piles are briefly analyzed; and then the 2-D and 3-D FEM models of pile-soil system are proposed by using the finite element analysis software ABAQUS. Differences between the FEM and the analytical solutions are compared through two illustrative examples calculated respectively by M-method which is used in the current code and by Poulos elastic theory method. Good agreement is found between the results from FEM calculation and the analytical solutions, which proves the reliability and efficiency of the FEM model given in this paper.

A three-dimensional elastoplastic finite element model is used to analyze the behaviors of cast-in-situ concrete thin-wall pipe piles (referred to as PCC)under lateral loading; and the rationality of the model is verified through comparisons between calculations and field test results. Using this model, the factors such as pile length, pile diameter and modulus ratio of pile to soil that affect the behaviors of PCC piles are also analyzed. All results show that: when the ratio of pile length to pile diameter is less than 8, the pile behaviors as a rigid pile, which makes a whole incline; otherwise, the pile behaviors as a long elastic pile and the pile responses mainly focus on upper part about 1/3 of the pile length. When diameter becomes larger, the lateral deflection of pile becomes smaller, but the pile maximum moment becomes larger and the site of maximum moment becomes lower. At last, with the ration of pile modulus to soil modulus increment, the lateral deflection decreases and the maximum moment becomes increscent.

Although the preloading method with vacuum and surcharge has many advantages, but it also has some negative effects. Firstly, it may lead to instability of embankment especially when fill is constructed in a short period and vacuum is unloaded immediately after finishing of surcharge because the undrained shear strength will decline with the unloading of vacuum. Secondly, it may lead to more settlement after construction especially when pavement is constructed immediately after unloading of vacuum for the value of compression modulus will decline with the unloading of vacuum. Other negative effects such as cracking and settlement of ground near the improvement zone have been reported in other papers already.

Considerating reinforcement and curtain effect, flexibility coefficient of pile is obtained by means of shear displacement method. Theoretical solution between settlement and load of pile is deduced according to physical relation of pile head and pile bottom on the basis of soil layered model. Comparative result of engineering example demonstrates that the pile groups settlement computation method is feasible. Moreover, the analysis indicates that the soil layered distribution in the reinforcement area influences the pile groups settlement; the increase of soil modulus can reduce its settlement effectively.

Ram-compaction piles with composite bearing base, which has the function of densifying the foundation and enlarging the end area, is composed of Ram-compaction Piles, steel concrete formed by the non-plastic-concrete, packing, etc.. The action mechanism of the Ram-compaction piles with composite bearing base was analyzed. Based on the practical case, the K. Terzaghi formula and theoretical formula are applied to calculate the capacity and settlement, the calculated results were compared with the testing results. The results show that the theory is more conservative than the testing. The improved method was presented.

The analytical solution of a single pipe pile under axial and lateral loads is presented, when the lateral load is optional free load. As pile foundation is becoming a preferred foundation type in high buildings and wide-span bridges, piles usually work under simultaneous axial and lateral loads(inclined loads) in engineering, then increasing efforts is being focused on the behavior of piles under inclined loads. Semi-empirical formula and Zhang’s formula have been used to calculate pile’s behavior under inclined loads by scholars at home and abroad through practical and theoretical studies. To analyze the function of free loads to pipe piles under inclined load conditions, on the basis of m method, deformation differential equation of elastic piles under inclined loads is established first with analytical method. Differential equation has two parts according to the piles in the earth or in the air, and lateral deformation, obliquity, moment, shearing force of the piles can be gotten respectively by solving the equations. Finally, influences of the top axial loads, the top lateral loads and the free loads, on several parameters are analyzed; and their influence curves are given.

When driving piles in the saturated soft foundation, soil surrounding pile will bear high squeezing stress which will cause high excess pore pressure. When the excess pore pressure dissipates, the effective stress in soil surrounding pile will increase accordingly, and the bearing capacity of the pile will be heightened gradually in this period. Considering the squeezing effect in the progress of sinking pile, the squeezing behavior of the concrete-cored sand-gravel pile is analyzed by applying cavity expansion method and consolidation theory. The squeezing effect of the concrete-cored sand-gravel pile is strikingly weaker, and its superiority is also revealed by analyzing the time effect of single pile lateral frictional resistance.

The wave velocity is the main physical parameter of ultrasonic wave CT test, it can distinguish the change of strength and density in reinforced section. The absorption coefficient is the main physical parameter of electromagnetic CT; it can determine the distribution of the reinforced section. CT has been applied to evaluate the grouting effect of group piles in Su-Tong Bridge. According to the results of coring and CT test, it is practicable to apply ultrasonic wave CT and electromagnetic CT synthetically to test the grouting effect of overlength piles.

Through the methods of theoretical analysis and field observation, the settlement of soft ground in Dongxihu section of Beijing-Zhuhai Expressway has been analyzed and controlled. Equivalent consolidation coefficient method has been employed for 2D-FEM based on Biot consolidation theory. Based on the observed data, the post-construction settlement was predicted and pre-compression measure was adopted to control the settlement. The predicted settlement is very close to the measured values; and it is proved that the prediction is reliable and the post-construction settlement has been controlled effectively.

The soil liquefaction induced from earthquake and associated ground failure have been a major concern for geotechnical engineers in seismically-active regions. The harm of liquefaction and associated ground deformation can be controled using various ground-reinforcement methods; the macadam pile is the one that is commonly used. The effectiveness of macadam piles for the prevention of soil liquefaction during vibration period is often of three folds: densification, drainage and the reduction of the total cyclic shear stress in the soil. However, the design and evaluation methods remain focused on the densification of in-situ soils at present. In this study, the shaking table test is conducted to assess the effect of reducing the total cyclic shear stress in the soil for macadam piles as a liquefaction countermeasure. In a series of three separate model tests, the saturated sand is studied first without, then with stone columns. The effect of reducing the total cyclic shear stress is discussed based on the recorded dynamic responses and established theory model. The test and theoretical analysis results demonstrate that macadam piles can reduce the total cyclic shear stress in the liquefiable soil remarkably.

Not only is the suction bucket foundation subjected to vertical loading induced by weights of offshore platform and equipments, but also undergoes horizontal force and moment caused by winds and waves. Therefore the performance of bucket foundation subject to the joint loading of both vertical force (V) and horizontal force (H) is one of the key issues in design and construction of a bucket foundation. A 3-D FEM-based computational model of bearing capacity and failure mechanism of bucket foundation under the above joint loads is proposed and then numerically implemented using the general-purpose finite element analysis package ABAQUS. The normalized relationship between the factor of ultimate bearing capacity and resulting displacement is obtained by applying the displacement controlled method for homogeneous soft soil profile. The failure envelope of the foundation in the load subspace of vertical and horizontal forces (V-H) is determined by utilizing loading procedure of the Swipe test. The load-carrying performance and failure mechanism of bucket foundation under joint loading are interpreted from the standpoint of upper-bound limit analysis based on the deformation pattern obtained from numerical analyses. The numerical results computed using the proposed method is helpful to engineering practices.

The method of self-balanced measurement and its application to testing of bearing capacity of two man-excavated rock-socket piles in Jiangsu province, are introduced. On the basis of the testing results, the characteristics of bearing capacity of man-excavated rock-socket short pile are analyzed.

By using the finite element method(FEM), the numerical emulation experiments are carried out on the settlement of the multi-DJM-pile composite foundation. The load thickness and modulus of the cushion , the ratio of the pile’s length and diameter and the spacing between piles are analyzed, and the rules of the settlement of the multi-DJM-pile composite foundation during the whole loading period are obtained. The settlement of the multi-DJM-pile composite foundation increase nonlinearly increment with the load increasing. The thicker the cushion, the large the settlement of the soil between piles, at the same time the thickness of the cushion should be controlled in about 300mm and its modulus should be limited strictly. The side resistance of pile plays a more important role and the settlement of the pile and the soil has the same tendency while the pile’s length. The increment of the spacing between piles results in the obviously nonlinear settlement of the soil between piles.

The subsidiary stress of any point in composite foundation is superimposed by the upper China loading and those stresses caused by both soil and piles which include side friction resistance and end resistance. With assuming the semi-trapezoidal distribution of friction resistance according to load transfer and field test, and considering the size effect of pile, the subsidiary stress caused by side friction resistance and end resistance can be obtained by quadratic integral computation with Mindlin solution. The subsidiary stress caused by the upper loading can be obtained from Boussinesq solution. The total subsidiary stress is the sum of two parts of above. An engineering case study is also presented in this paper .

Through various physical and mechanical experiments on vibro replacement stone columns and soil among them, mechanical properties of vibro replacement stone columns and their reinforcement effect on composite foundation are investigated. It provides reliable technical reference for the design and construction of project. The results of the experiments can provide reference for design of composite foundation of vibro replacement stone columns in similar condition.

Based on analyzing the regularity of relation between side ultimate friction resistance and pile length, under reasonable assumptions of stress fields near pile tip caused by side friction resistance, formulae for foundation stress fields near pile tip have been derived. The relations between the maximum stress and some sensitive factors such as pile length, pile diameter, internal friction angle of soil and load of pile top are deduced. The study provides useful references to the analysis of other underground structures near pile tip.

Fiberglass-reinforced plastic (FRP) composite sheet pile has relative low elastic modulus and the shape of the thin-walled structure in which excessive deflection will occour. And this will effect its normal operation. The deflection of FRP sheet pile includes bending deflection and shear deflection. A simplified method is introduced to calculate the deflection of FRP sheet pile wall. The maximum deflection obtained from this method is very close to that from finite element method; and it is shown that the method proposed is quite reliable.