The control equations for analyzing coupled thermo-hydro-mechanical phenomena in saturated-unsaturated porous media established by the author are described. Aiming at the axisymmetric model test for geological disposal of high-level radioactive nuclear waste and the parameters of material for analysis in Task-2 of DECOVALEX II, a numerical simulation for the coupled thermo-hydro-mechanical process in the buffer-rock system is carried out by using FEM code developed by the author. The distributions and changes of temperature, water content and contact stress in some parts in the buffer and the rock are investigated. Through comparing the simulation results and the results obtained by measuring and THAMES program, the different and the identical parts in three results are showed and the possible influence factors are pointed out. So it can be considered that the FEM code developed for simulation of coupled thermo-hydro-mechanical processes in geological disposal of nuclear waste is reliable and practicable.

In light of the stability of coastal levee on soft foundation, according to the time-dependent properties of soft soil and the coupling properties of seepage field and stress field, creep model of soft soil and analytical model of coupling stress field are established; and the deformation properties are analyzed by taking the coastal levee and its foundation as a whole. The overall stability under the coupling force of dead-weight, wave force and seepage force is analyzed by the shear strength reduction with FEM. Results show that the coastal levee structure under the comprehensive functions of many effects, not only there are more impact on displacement field and stress field of foundation and section, but also the overall stability. The validity of the model and computing technology is proved by compared with the measured data; and the conclusions obtained in this paper have theoretical meaning and practical value.

With the implicit rock-bolt element adopted, the behavior of underground tunnel excavation and support is analyzed by using three-dimensional computation method, which can reflect the reinforcement effect on surrounding rock with fully-grouted bolt and shotcrete support. The principle of this method is used to establish a fully-grouted rock bolt element model which comprises rock materials and bolt materials. The implicit bolt element and spray layer element, which are implied in the rock element, could be independent of the influence of mesh division, so the mesh generation of the large scale reinforced rock structures becomes relatively convenient and feasible. With this method, the influence of rock-bolt parameters on underground cavity excavation could be effectively reflected; moreover, it is feasible to simulate the time-effect of steel framework and rock-bolt structure. Applying the method mentioned above to the practical engineering, the finite element calculation results preferably reflect the behavior of reinforcement of fractured rock mass with the support of rock bolts, shotcrete and steel framework. An efficient and quick computation method is provided for the design of underground cavity excavation and rock reinforcement.

It is well known that in the deformation and failure process of rocks, a rock system will constantly readjusts its structure to resist the external pressure when it develops to an unstable crack propagation period. Thus, the cracks are gradually concentrated to a local area orderly; and the strain energy is continuously dissipated. The system will have an energy circulation with the negentropy flow that is produced and added by an external disturbing. At the same time, the entropy of the system, which shows the chaotic degree of the structure and energy, is decreased; meanwhile, the dimension of the system shows that the uniform degree of the structure and spatial distribution of energy is decreased too. The rock system is far from the equilibrium state in this period; and the failure process means a catastrophic process of the system entropy. Based on the realization which is discussed above, the paper derives an entropy equation which contains structural factors and energy distribution on the basis of testifying the uniform of strain energy distribution and structural block distribution mode. By giving an equilibrium analysis of the entropy equation, the bifurcation set shows the local catastrophe is obtained; so, the entropy fold catastrophic failure criterion shows a local failure of rocks is obtained. Meanwhile, the cusp-catastrophe represents the degree of order of rock structure by entropy equation is discussed; By finding the solution of the bifurcation set of a rock system, the bifurcation set is the integrated failure criterion which is shown the entropy catastrophe of a rock system.

The grain of Aeolian sand is fine; the geometric gradation of the particles in Aeolian sand aggregate is not good; and it is a kind of non-cohesive material. The aeolian-sand has different mechanical property from common material. The typical aeolian sand in Xinjiang, Inner Mongolia and Shaanxi are adopted to test the grain gradation, natural water content, relative density of the material. For the aeolion sand the CBR, resilience modulus, compress and shear tests are also carried out in the laboratory. The testing apparatus and methods are remade according to the property of aeolian sand。The tamping pressure-strain and other property are analyzed by the way of chart and regression algorithm. In the course of test, the authors use aeolian sands which have different dry-densities and water contents and gains the stress-strain curves in different compaction standards.

A new compound model is developed to calculate volumetric strains of unsaturated and saturated collapsible loess. In this model, loess is regarded as the compound of undisturbed and disturbed parts, both of which are respectively and uniformly distributed in loess; and the proportion of the two parts can be calculated through the combination of a pore size distribution curve; a suggested geometric structural model and structural instability criterion with the generalized suction being considered. The volumetric strain increment includes three components: the elastic increment of undisturbed part; the plastic increment of disturbed part determined by the application of the generalized suction theory; and the structure collapse contribution which is particularly relevant to the change of void ratio from undisturbed soils to disturbed soils. The relationship between the angle-stiffness of the structural instability criterion and the degree of saturation is determined by the structural strengths revealed by compression tests of natural loess. The rationality of this model is verified by comparing calculated results with published experimental data.

The consolidation drained shear tests for municipal solid waste (MSW) samples were conducted using large-scale triaxial apparatus: Based on the test results using traditional geotechnical concepts and methods, the shear strength mechanism of MSW is investigated. The shear strength properties of MSW related to large deformation mainly resulted from the reinforcing effect of fiber materials .The shear resistance of MSW includes friction function and tensile force provided by fiber materials. The friction strength of MSW is composed of three parts: the friction function between fiber phase and particle phase, the friction one between fiber phases, and the friction one between particle phases. Based on the shear strength property of MSW, the stress-strain curve is simulated by Duncan-Chang constitutive model.

Based on the analysis of microcosmic mechanism which is caused by rock mass mechanical property and acoustic emission in the course of rock slope failure, and through rock Acoustic Emission trial and monitor example of rock slope Acoustic Emission, the acoustic emission features of rock slope are studied; and the basic mechanical classification of deformation and failure of rock slope and the monitoring-predicting methods and criterion of AE are put Arward, and the forecasting of rock slope failure is implemeted. The research result shows that one or more peak values of acoustic emission appear before the failure of rock slope; the application of AE technology can determine the stress concentration and active areas during the deformation of slide slope; for the rock slope with decreasing “sliding resistance force”, the failure prediction criterion is that the AE major events rate is more than 15 times per minute and the forecast time is from several minutes to hours; for the rock slope with the increasing “sliding force”, the AE major events rate is more than 26 times per minute and the failure will occur in 30 to 45 days after the first peak value of acoustic emission.

Relying on the open excavation section of Jiang Bei of the Yangtze River tunnel in Wuhan, a series of drained triaxial tests on unloading stress paths at K0 consolidation have been carried out with undisturbed silty clay. And the deformation characters under unloading were deeply analyzed. Analysis shows that stress-strain curves and stress paths have close relationship and the stress-strain curves under unloading are similar to a hyperbolic type. According to the stress-strain curves, unloading stress paths can be divided into two groups A and B. The stress paths of group A exhibit axial compression and ones of group B show axial tension. The normalization of its stress-strain relationship is very good under unloading stress paths for undisturbed silty clay. The stress-strain curves of different confining pressures in the same stress path can be normalized with average confining pressures. But normalized equations of groups A and B are different. Additionally the normalized equations of all stress paths have been given. This outcome can be used to further research on both deformation parameters and constitutive equation of soils under unloading.

In consideration of the deficiencies of quadratic-function-response-surface method in structural reliability analysis, an improved response surface method is presented based on high-order-response-surface function and iterative rule with the geometry principle of JC method to decide center point. Reliability analysis of piles under inclined loads is done by the improved response surface method; reliability indices of piles with excessive top horizontal displacement and of piles with material yielding are calculated; and comparisons between results by the improved method presented and results by Monte-Carlo method and quadratic-function-response-surface method are done. The calculation demonstrates that iterative loops are reduced; precision of results and stability of numerical experiments are improved in the application of the improved response surface method; and the improved method is suitable for the reliability analysis of large-scale complicated structures.

Complex method (CM) of traditional optimization methods combined with simulated annealing (SA) of intelligent optimization methods; and a new type of intelligent computation method, complex simulated annealing (CSA), was developed. Simulating analysis results show that the CSA has outstanding advantages in searching performance compared with the complex method or the simulated annealing. In addition, an optimization design model for cement-soil retaining wall (CSRW) was set up according to Chinese design codes; and the CSA was successfully applied to the optimization design of CSRW. Two case studies were given to verify the proposed method. The comparing computation results show that the proposed optimization method is feasible and reliable. Finally, the influence of reinforcement of passive earth pressure area located inside foundation pit on the embedded depth and effective breadth of CSRW was discussed.

At present, the tunnels and big underground space were excavated in the fractured rock; their stability are controlled by crack growth condition and distance from crack and tunnel and underground space. By applying the new boundary integral equation (BIE) for two-dimensional elastic bodies containing cracks and holes to couple the element-free Galerkin method, a new boundary element-free solution for calculating the interaction between cracks and holes is presented. The basic unknown in the new boundary integral equation is a complex boundary function , which is a linear combination of the boundary traction and boundary displacement density. The present BIE formulation can be related directly to Muskhelishvili’s formalism. The constructed methods of the element-free try functions are introduced into the new boundary integral equation to develop the new boundary element-free solution. At last, the validity and accuracy of the presented method are illustrated by the elastic mechanics problem containing cracks and tunnel from that the method results agree well with those obtained from the analytical solution.

Based on Mindlin displacement solution subjected to centralized load，the settlement coefficient subjected to uniform load is proposed. Simplifying the interaction between foundation with free boundary and ground soil, the formula of interaction taking into account interaction between foundation and subsoil is obtained. Considering the condition of rigidity or flexibility foundation plate, a comparison between Mindlin solution and Boussinesq solution results is made with the load condition of centralized load or uniform load. The results indicate that the depth ratio has an important influence, the results of foundation settlement, groundsill counterforce and the bending moment of foundation plate. The settlement coefficient considering depth ratio is presented; it can be referenced in practice.

In order to solve the high viscosity problem of the crude oil, the steam stimulation technology is generally adopted in heavy oil reservoir exploitation. Based on the continuum mechanics theory, an improved thermal-hydraulic-mechanical coupling model which considers the influence of heat convection is established to quantitatively evaluate the formation pressure, deformation and effective stress under steam injection conditions. The Galerkin finite element method with the fully implicit and sequential algorithm is used to simulate the thermal-hydraulic-mechanical coupling process around the injection well. The results show that the high pressure which is caused by the higher thermal expansion of fluid may lead to displacement, deformation or even failure of structure; and the temperature has a great influence on the fracture geometry of the formation. The study indicates that this enhanced model is more exact and practical than the classic method and can be applied to optimizing the steam injection rate, investigating the combined effects of the reservoir, geology, thermal-hydraulic response, in-situ stress, etc.

The 2004 Chuetsu earthquakes of Niigata (Japan) triggered numerous landslides, and the most widespread types of landslides were highly disrupted, relatively shallow slides and soil (debris) flows. To avoid and mitigate such seismic landslide hazard, this paper presents a method to evaluate the probability of slope failures using Newmark displacement on a pixel-by-pixel basis in a given area. The proposed method was able to integrate Newmark displacement modeling and Monte Carlo simulations with geographic information systems (GIS). In the modeling, an empirical attenuation relationship was utilized to calculate Arias intensity over this study area; and the variability of geotechnical parameters was taken into account to calculate coseismic displacement. After deriving the displacement from related inputs, the Monte Carlo simulations ran 1 000 times, and generated 1 000 displacement values for each grid cell; and then the displacement mean and standard deviation were calculated and its probabilistic distribution can be obtained. Finally, given 2 cm as a threshold value of displacement, estimated probabilities of displacement exceeding 2 cm were shown as a map of seismic landslide hazard. The resulting map was classified into four categories from very low to high level.

Numerical simulation and experimental testing are used to research the wave propagation characteristics and the forming procedure of interfacial wave in grouted rock bolt during embedded concrete curing. Both show the wave propagation characteristics will change with concrete curing. The P-wave in the grouted rock bolt is very sensitive to mechanical characteristics of embedded material, and with the increasing of concrete strength it will disappear. When the strength of concrete get harder interfacial wave will form and dominate; the velocity of interfacial wave is related to embedded material so it can be used to measure grouted quality of rock bolt as well as grouted length.

Considering the environment behaviors of contaminant in soil, such as diffusion, equilibrium/nonequilibrium two-site absorption-desorption and microbiological degradation, the kinetic model of the contaminants transport in soil is established; and its finite difference equation is given. Based on it, the distribution regularities of the contaminant concentration in soil are discussed in detail; and the sensitivities of parameters and are analyzed. The study shows that the parameter has important influence on the concentration distribution in soil and the influence degree is also related to the proportion (1- ) of nonequilibrium sites to total sites; At the later stage of pollution, the existence of absorption phase may increases the solute concentration in the water in soil; and the lager is , the more obvious is the influence.

The essential of rock damage evolution is the deterioration of rock’s meso-structure, which also appears on the surface of rock. The tension tests of limestone samples were employed in the test machine assembled with scanning electronic microscope, and simultaneously the SEM image of sample surface was captured while the sample is being loaded. It is observed that the surface pattern of rock transforms irreversibly and eventually macro cracks appear on the surface due to tension. Moreover the SEM image is analyzed by the method of digital image processing, which includes threshold partition and edge detection, and then the fractal dimension of rock surface is calculated as a parameter to characterize the meso surface pattern of rock. It is concluded that the fractal dimension increases with the increasing of load, and at the same time damage become more severe.

The permeability and diffusion are employed to analyze the retention mechanisms of clay-solidified grouting （CSG）curtain to contamination in landfill. Its permeability and diffusion capacities of CSG curtain to heavy metal cations are obtained by column test. Using 1D flow and transport model which can take convection and dispersion of wastes into consideration, the contaminants transport process through CSG curtain is evaluated. The test results show that the permeability and the diffusion capacities are different for different heavy metal cations; and transport velocity of cadmium is more quickly than lead. It is found that the most important factors affecting the transport process of heavy metals include the thickness, permeability, diffusion capacities and hydraulic gradient.

For being difficult to solve the problem of multidimensional continuous parameters in the back analysis by the ant colony algorithm, stochastic experiment ant colony algorithm is brought out by the idea of evolution of ant colony algorithm. The method does stochastic experiment to determine the influence of each level of parameter. So the visibility and the probability of each level of parameter is determined by the influence of each level of parameter. At the same time, the analysis of variance is used to make sure whether the level of parameter is important or not. If the level of parameter is not important, then the pheromone is very low, so the speed of the convergence of objective function is accelerated. The validity of the method is proved by an example used in the back analysis of geotechnical engineering.

Measurement and analysis of geostatic stress by using radial deformation of borehole and wall stress of hole, it must be related with stress distribution near borehole in rockmass. For stress distribution near borehole in orthotropic rock matrix, it is difficult to obtain the analytic expression of stress through the method of solving partial differential equation; and it directly influences the accuracy of results of geostatic stress. Through constructing stress function, the stress near the borehole is solved with stress calculus of variations. That supplies theoretical foundation for accurate analysis of geostatic stress in orthotropic rockmass.

A model has been developed for shear distribution at the pile/ rock interface in a single rock-socketed pile subjected to vertical loading. Which accounts for the interfacial bond condition and is based on a shear-lag analysis. The new closed form solution has been established for a single rock-socketed pile under vertical loading. And to investigate the influence of relative rigid of pile/rock and loading grade on load-transfer of rock-socketed pile is discussed.

Since the discontinuous deformation analysis method (DDA) has been developed， more and more advantages are being displayed in simulating large displacement and deformation of the system of discrete bodies. In this method， however， some artificial parameters have to be preset， which more or less affect the results. By means of a simple model involving only one slide body， the effects of those artificial parameters such as the step length and the stiffness of contact springs on the results are analyzed. It is pointed out that only in the proper ranges the larger time steps and larger stiffness can give rise to better computational results. Some reasons of leading to theses results ate discussed. The lower bounds and the upper bounds for the artificial parameters are suggested.

The three-dimensional scattering and diffraction of plane Rayleigh-waves by a hemispherical valley is studied. The deposit and the half space is simulated by elastic single-phase media. The Fourier-Bessel series expansion technique is used to get the analytical solution for the first time. The results of surface displacement amplitudes are presented; and the effects of frequency and angle of incident waves on the surface displacement amplitudes are discussed.

Most natural clays have structural property; the experiments show that the influence of loading ratio on the settlement property of the structured soft clay is notable. The loading ratio increases the shearing trend in soft clay, which depress structure strength, structure yield stress and compression index. Based on the experiment, soft clay settlement calculation method considering influence of loading ratio is presented. The examples show that the bigger loading ratio in the course of loading enlarges settlement of structured soft clay ground. For the sake of reducing the influence of loading ratio on settlement property, it is suggested that the loading ratio of structured soft clay 1:0.25 or 1:0.5 should be adopted. If the loading ratio of structured soft clay is bigger than 1:1, it is not suitable.

Based on Euler backward integral method, an integration algorithm of constitutive equation is suggested for adaptive sub-stepping schemes. And the consistent tangent matrices are derived. According to the projection vector of trial stress beyond the yielding surface, the pseudo yielding function and plastic potential function is introduced for apex area of yielding surface. So, integration algorithms adopted of two projection vectors make trial stress in apex area to return to apex point of yielding surface. The consistent tangent matrices for two vectors are also derived. Zero stress point in the yielding surface is replaced by minimum value. An ABAQUS-UMAT subroutine using D-P criterion for linear elastic-perfectly plastic model is programmed; and two examples are analyzed to validate these methods.

The sensitivity analysis method of landslide stability based on models of influencing factors is conducted to analyze sensitivities of influencing factors in their definition domains. This method regards influencing factors as sub-sequences, the corresponding safety factors as target-sequences. The area probability functions of influencing factors, which are calculated by cumulative distribution functions of sub-sequences, product with difference values of target-sequences respectively; then, results that are produced by those two values are summed to get decision values of sensitivity. With this method, taking Taishanmiao landslide for example, which is located at Fengjie county in the Three-Gorges reservoir. Based on the distribution functions of shear strength factors by analogy and statistics and the ones of maximum horizontal acceleration of earthquake and water level fluctuations by empirical analysis, the most sensitive factor among all influencing factors is obtained. Finally, the relation between the sonsitivity of landslide stability and variances of influencing factors is analyzed on basis of internal friction angle.

The nonlinear failure criterion is employed to determine the active earth pressure and the position of slip surface in this paper. Firstly, the variables and are created by tangents method, then and corresponding to different potential slip surfaces are calculated by iteration method and the active earth pressure is obtained by using generalized Coulomb soil pressure theory. The slip surface, which has the maximum active earth pressure, should be the most dangerous slip surface, and the maximum active earth pressure is also what we desired. After comparing with the research results by Mohr-Coulomb linear failure criterion, it is concluded that the active earth pressures behind the rigid retaining walls, which are calculated by the nonlinear failure criterion, will be more practical and accurate, while adopting the Mohr-Coulomb linear failure criterion will provide a lower active earth pressure values, therefore, will cause insecurity in real project.

By the in-suit investigation of some Lot of Shenzhen Metro project PhaseⅠand the test and construction monitor results, comprehensive research have been achieved in stratum and tunnel structure deformation. It is shown that tunnel vault settlement is more than ground settlement in watery, weakly and sandy stratum; then 3D movement trend of stratum deformation and construction space-time effects of each excavation step of overlap tunnel are gained. Finally, excess pore water pressure are measured around tunnel structure; and the distribution and movement regularity with excavation are displayed in no precipitation condition. The results can be used for reference in design and construction of metro tunnels under similar stratum.

The peak strengths and corresponding strains under different confining pressures are important controlling data of stress-strain curve in rock triaxial compression; and the values of peak strength and corresponding strain will usually increase if the confining pressure is improved. The results of tests show that the relationship between the peak strength, corresponding strain and the confining pressure is nonlinear.The particle swarm optimization (PSO) based ANN, which is improved with simulated annealing technique, is applied to establishing the relationship between the peak strength, corresponding strain and the confining pressure. An example is studied; the results show that the proposed method is feasible.

Slope engineering is a dynamic, fuzzy, open and complicated nonlinear system, which makes it difficult to evaluate complicated slopes conforming to reality by the traditional analysis method. The factors which control and affect slope stability are random and fuzzy variables. As artificial neural network can consider both quantitative and qualitative factors, it is suitable to solve the uncertain problems, such as the estimation of slope stability. In consideration of influencing factors of the slope stability, a fuzzy neural network model based on genetic algorithm is established to predict slope stability, and many engineering data are collected to train and examine the model. Compared with the BP neural network, the presented model has higher predicting accuracy.

The state-of-art of unsaturated soils strength and the angle of internal friction with matric suction indicated by Fredlund are introduced; and the law of is analyzed. With the test results of plane strain constant stress ratio-unloading of undisturbed expansive soils, the angle of internal friction with matric suction calculated by Fredlund’s method is great than the effective angle of internal friction . The result is not accord with Fredlund’s theory; the reason is that micro- crannies were puffed during unloading test so sa to reduce the matric suction. More experiments analysis must be taken.

Three-dimensional nonlinear elastic finite element method had been developed to study the negative friction behavior of the row piles subjected to surcharge nearby. The influence of the space between the row piles and the distance between surcharge and row piles on the negative behavior of the row piles was analyzed. The varying law of the axial force of this kind of piles was posted. Study showed that the axial force of piles increased as surcharge increased. While surcharge increased to a certain value, the soil between the piles brought soil-arch effect and then the axial force of piles decreased a little. While surcharge increased continuously, the soil-arch effect suffered destroy, the axial force of piles increased again. While surcharge increased to a certain value, tensile stress produced partly in the top of piles, it increased with the growth of distance between surcharge and piles, middle piles were more tensile stress than side piles. The most axial force of piles lay in 0.65－0.75 time pile length; side piles were more axial force than middle piles. With the increase of piles’ space the axial force of the piles increased; and soil-arch effect dented. The axial force of piles reached maximum, as a certain distance between surcharge and piles.

Uniaxial compression tests for frozen clay were accomplished in test machine with environmental control equipment, which the samples were taken from outside after the clay frozen. Relationship between load and deformation was achieved, compression strength and accordingly deformation were given out, and failure features were observed. The tests show that under the specified test temperature -15 ℃and loading rates range of .5×10-2-1.0×10-5 mm/s; the frozen clay samples have the same features: elastical characteristics shown in first, then some micro cracks born and with the development of micro cracks, macro cracks developed; and samples get to failure at the end. The features shown in our tests are different from that of the remoulded frozen clay.

Considering parameter uncertainty in rock mass stability analysis, the finite element analysis (FEA) model of plane failure slope is set up based on ABAQUS. The model is used to perform the numerical simulation of slope stable state, to acquire the data for adaptive neuro-fuzzy inference system (ANFIS) analysis. The model, on rock mass mechanics parameters and anti-slide and down slide forces, is established based on ANFIS; then the statistical. characteristic of anti-slide and down slide forces is obtained. The program to solve slope failure probability and reliability is compiled with Monte-Carlo and Matlab, and used to analyze the slope reliability of Xuefeng open pit in Hunan Province. The result manifests that this method can avoid compiling redundant FEA program, reduce computational time, and improve computational precision.

A three-dimensional model to predict soil rotary cutting resistance is established besed on the traditional straight soil cutting theory; and the formula is given to calculate the resistance. The model considered the lateral shear failure; and true cutting angle is smaller than tool angle. In order to check the model, test were conducted using different tools in sandy soil; the torque during the expressional test has been gained. The calculated values value fit well with the observed values. The result showed that the nonlinear relationship between the cutting angle and resistance varies for different soil, which optimized cutting angle is existent for different soil. The toothless tool have larger cutting resistance and more sensitive to the cutting angle than the ones with teeth.

Although the measurement of physical phenomena such as pore water pressure, displacement and load is routinely carried out with a high degree of accuracy both in prototype and in small scale centrifuge models, the accurate derivation of soil stresses poses a number of problems. The design criterion is first reviewed and discussed with focusing on cell and soil effects. Key guidance is proposed by introducing flexibility factor in the design of earth pressure cells. A new kind of miniature earth pressure cells is developed to measure boundary total stress in a multi-gravity environment. The performance of their calibration is given under pressure of water, dry fine sand pressure and saturated fine sand produced in flight of centrifugal acceleration. An application is also reported of the newly developed miniature earth pressure cells in measuring lateral soil stress against a single wall in ground of dry fine sand. A reasonable K0 value is derived from the measured earth pressure, demonstrating their accuracy in the measurement of boundary total stress in a multi-gravity environment.

In lingt of the anti-permeation performance problem of soft rock tunnel under the condition of shotcrete in glide structure area of West Henan, and from the basic theories of cube laws, combined with characteristics of laminar flow of ground water, and according to the different constructions condition, the analogue experiments of permeation properties of cementation plane are carried out; and homologous calculation formula are deduced. By comparison and analysis of the result,we can clearly understand the process and the mechanisms of interaction between various influence factors such as rock character, roughness, interface agent and large fluting, etc. It is concluded as follows:(1)as soft plane in constitution, permeation performance of cementation plane is far greater than that of rock mass and concrete; in the same , permeation performance of cementation plane of soft rock with coarse grain is also greater than that with fine grain; (2) restriction of roughness of rock mass,utilization of interface agent and set appropriate fluting on cementation plane can all increase its anti-permeation performance; and(3)load conditions of rock mass influence anti-permeation performance of cementation plane to a great extent.

By utilizing an improved direct shear creep apparatus, exploration to the rheological characteristics of soft clayey soil affected by mineral composition and its content in soil is performed; and rheological characteristics of three sets of soft clay samples with different contents of kaoline and bentonite, respectively, are tested under the same test conditions. The test results show that mineral composition and its content are two important factors on rheological behavior of soil; the viscosity coefficient of the soft clay reduces as the increase of the clayey mineral content; i.e. that rheological strain resistance decreases with the increase of the clayey mineral content. It is concluded that clayey mineral affects soil rheology characteristics by the way of water bounded mineral particle surface; furthermore, firmly bound water is a key factor and loosely bound water is only a secondary factor. The test results make a contribution to understanding of the origins of soil rheology and are of guiding significance for improvement and perfection on existing computing theories of rheology deformation of soft soil.

The consolidation coefficient is key parameters in the soft clay engineering. At persent, the consolidation coefficient is obtained mainly by the lab oedometer and back analysis with in-situ observed settlements. But the lab coefficient is much less than that from back analysis of in-situ data. The sample disturbance is an important factor. The coefficient after disturbance is achieved with the disturbance degree proposed by Hong & Onitsuka; After validation by former research, the coefficient is discussed.

For the large scale of regional seepage fields the horizontal 2D FEM is usually chosen as the analysis tool which assumes that the hydraulic head loss caused by vertical flow can be ignored. However, the hydraulic head loss around suspended structures is apparent. If the horizontal 2D FEM is used to model the suspended structures a major error will occur. In order to simulate suspended structures using the horizontal 2D FEM, a contact element is introduced. The contact element is used to consider the hydraulic head loss caused by vertical flow near suspended structures. The matrix equation of contact elements is deduced. The deduction is based on the coefficient resistance method and the analytical solution of flow near suspended cut-off walls under plane condition. The corresponding procedure is programmed. Two examples are studied. The result accuracy is assessed by comparison with 3D FEM. It is shown that they coincide each other on discharge; and that the hydraulic head gained by proposed method is the mean value of that computed by 3D FEM at the same location. The method presented is an effective way to simulate suspended cut-off structures in regional seepage fields.

There exists disunity, even wrong phenomenon in geotechnical community when determining and choosing strength index. The detailed several aspects are shown as follows: (1) the classification of strength test; (2) the measurement of undrained strength; (3) the strength index determination and choice for loading project; (4) the strength index determination and choice for unloading project. In above mentioned several aspects, it’s pointed out that unconsolidated-undrained test is fit to be named “natural consolidated-undrained test”. All kinds of methods measuring natural foundation soil strength are discussed and compared. Theoretical analysis of modified effective stress method and effective consolidation stress method created by Chinese scientists is made; and the results indicate that both methods conservatively estimate in-situ strength. The correspondent confining pressure formula of isotopic consolidation to model K0 consolidated state and the strength increase formula by effective consolidation stress method adopting CIU strength index equivalent to CK0U strength index are derived. The “undrained” effective stress analysis, QRS method, undrained strength analysis method are introduced. It’s pointed out that SHANSEP method adopted by undrained strength analysis can well model strength increase of foundation soil during construction stage and is fit for China to adopt. The application occasions of loading -unloading - loading way to get the unloading strength index commonly used in China are analyzed.

Through analyzing the propagation process of stress wave in the vertical direction at the joint, the expression of a series of echoes generated at the joint are achieved; then the combined vibration at the initial wave source is determined; finally a inverse model to detect the joint’s characters based on signal process of the vibration is given. Utilizing this inverse model we can detect the joint’s location, characteristic impendence, quality factor and the ratio of its width to its velocity for stress wave; furthermore, the characteristic impendence of the rock located at the other side of the joint can also be detected. This conclusion would absolutely enhance the application of stress wave in detecting jointed rock masses.

The construction technology of vacuum preloading in the stratum with confined water is describde in detail. It is safe and economic that the technology of ‘tearing membrane’ is combined with the ‘non-tearing membrane’ while driving PVDs. The effective method is elaborated while repairing the loss of sand cushion. It is presented that recycling water could deal with the leakage of deep soil in vacuum preloading. Lastly other important technologies such as outlet assembly, elimination of typhoon damage and the problem of excavation of interlayer are put forward.

It is the first time in China to construct such a huge lake like the Dragon Lake in the Zhengdong Xin Region of Zhengzhou. On the condition of the average lake depth 4.5 m and on the basis of achievement, we adopt such methods as fieldwork, in-situ and laboratory tests, water quality analysis and numerical analysis to study the excavation of the Dragon Lake and seepage control scheme with experiences of practical project. The result indicates that it is better to use dry and wet methods to excavate the main lake district of the Dragon Lake and to eject soil into water to control seepage. It can form the lake and has no significant impact on groundwater system and geological environment in the nearby area. It also can meet the water quality request. It is also reasonable and feasible from the angles of construction equipment and project investment. In addition, it is considered that it should perform pre-excavation test in-situ and optimize excavation and seepage control programme perior to the formal excavation of the Dragon Lake.

After water impounding, hydrogeological condition in the reservoir area varies obviously and landslide stability is affected. Taking a reservoir in Southwest Hubei for example, general law of influence of reservoir water level on landslide stability is discussed. By use of push method, anti-shearing parameters, affection by water level variation and drainage factor is analyzed. Additionally, numerical simulation are adopted to analyze its sliding mode. It is showm that reservoir water impounding not noly influences landslide stability but also the failure mode, i.e.the that is to say, push mode will be substituted by drag mode.

A hypoplastic constitutive model and hypoplasticity are described briefly. A procedure for the determination of its parameters is described in detail. This model is based on nonlinear tensorial functions and is developed without recourse to concepts of elastoplasticity theory such as yield surface, plastic potential, flow and hardening rules and decomposition of deformation into elastic and plastic parts. The paper also presents the hypoplastic model that is capable of capturing the salient features of granular materials，in particular, for problems involving extremely low stress levels or extremely high stress.