Superhigh arch dams generally locate in complicated foundation. The failure，reinforcement and stability mechanism of foundation are facing with challenging original problems，such as：mechanical parameter and strength reasonable selection of jointed rocks；cracking problem in the heel and toe of dams；reinforcement measures for atypical faults and altered rock；grouting timing design for toe area of dam；anchorage force damage and nonlinear evaluation for integrity stability. In this paper，these key problems involved in the research methods，and reinforcing measures to carry on the discussion and analysis based on practical engineering. The micro-macro transfer method is proposed for coupling nonlinear analysis method. By employing this method，numerical simulation and experimental investigation on foundation failure，reinforcement and stability evaluation of superhigh arch dam need to further carry out for servicing dam design and construction.

An anisotropic damage model and an effective thermal conductivity model were presented based on homogenization techniques for low-porosity brittle rocks subjected to mechanical and thermal loadings. The thermal effect，the recovery of normal stiffness and the mobilized dilatancy behavior were incorporated in the damage model. The thermal conductivity model took into account the effects of damage-induced microstructure evolution，crack shape，porosity and saturation degree on the effective thermal conductivity of brittle rocks. The influences of crack shape and saturation degree on the effective thermal conductivity of low-porosity crystallized rocks were particularly discussed. The damage model was validated by the triaxial test data on an intact Äspö diorite；and the evolutions of porosity，crack density，crack shape，saturation degree and the effective thermal conductivity during the mechanical loading were demonstrated. The results may provide a helpful reference for better understanding the coupled thermo-mechanical behaviors of deep rocks.

According to the urgent demand for prediction and control of catastrophe process of landfill，the evolution mechanism of catastrophe process and necessity of studying on multi-field coupling were both thoroughly analyzed in the view of thermo-hydro-mechanical-chemical(T-H-M-C) coupling theory combining with the complex and special environmental geological conditions of landfill and its surrounding regions. Four models of biological-thermo-hydro(B-T-H) coupling model of landfill gas migration，hydro-biological-chemical (H-B-C) coupling model of leachate migration and transformation in landfill under the effect of aerobe and anaerobe degradation，hydro-chemical(H-C) coupling model of pollutant migration in composite liner system and thermo-hydro-mechanical(T-H-M) coupling model on dry cracking of closure cover system of landfill under the effect of heat quantity changing and vapor migration were established to provide an effective analytical method for predicting and controlling catastrophe process of landfill. Furthermore，the multifield coupling test and analysis system of contaminants transport in rock and soil，integrating monitoring，controlling and data acquisition into one body，was developed based on the proposed measuring methods and test technology. The on-line monitoring system integrating real-time monitoring and video supervising into one body was developed based on the formed multi-parameter remote synchronization monitoring methods and technology of landfill pollutants. Finally，according to the cracking issue of closure cover system of landfill，a new environmental protection technology of ecological sludge evapotranspiration technology was proposed. The above achievements can offer scientific means and technical support to predict and control landfill catastrophe；meanwhile，it also has important theoretical significance and application value in enriching and widening multi-field coupling theory.

Description on rock basic mechanical behaviour by particle flow code(PFC) starts from contact state among particles and change characteristics. PFC could overcome the difficulties of rock self microscopic behavior and realize the simulation of microscopic structure in rock model. All of those can not be solved by traditional fracture mechanics. The failure of Jinping deep marble is dependent on time. It can be simulated by the parallel-bonded stress corrosion(PSC) model in PFC. A numerical mode for rock that includes time-dependent behavior by adding a damage-raw law to the parallel-bond model is described. Combining with the static-fatigue data of Jinping marble，the microscopic parameters are confirmed in PSC model. The deformation，crack and failure behavior are analyzed in simulation by the test results of PSC under different driving-stress ratios. The results obtained by PFC are coincidence well with the microscopic behavior in rock failure process. The microscopic behavior can help us better to understand the brittle rock strength dependent on time.

Jinjishan tunnel in the second stage of Fuzhou airport expressway project is the first multi-arch tunnel with bidirectional eight-lane in China. There were developed joints and crushed rock in tunnel surrounding rock，and the characteristics of joint distribution had significant effect on the stability of tunnel surrounding rock. This paper collected the data of joints in several cross-sections of mid-drift and other outcrop areas of the tunnel，and predicted joints distribution of the main tunnel by using statistical analysis method. On the basis of this，the paper made simulation calculation for the deformation and failure process of the tunnel surrounding rock with the method of discontinuous deformation analysis(DDA). Meanwhile，it divided the typical stages of the deformation and failure process for the tunnel，and also indicated the most possible damaged parts. At last，the paper made a comparison between the result of DDA calculation and practical collapse of Jinjishan tunnel，which were almost the same. Therefore，it is shown that the DDA method is capable of analyzing the stability；and it has good application prospect of stability analysis for tunnel surrounding rock.

Rocks，concrete and other materials，due to the existence of inhomogeneity of mesoscopic structure，their fracture-broken development process and damage characteristics are associated with the distribution of micro cracks contained in the materials. Based on the idea of finite-discrete coupling analysis，a cohesive zone model based on elastoplastic fracture mechanics is employed to simulate the fracture of rock. In this model，the cohesive interface elements are inserted into the region of coarse aggregates and the parameters such as stiffness of the interface are deduced. If the interface cracks and failures，fracture will happen. Using uniaxial compression，a single particle breakage and slope instability simulation，the method is verified. The results show that this method can simulate the crack initiation and propagation effectively and reflect the whole process from small deformation to large deformation and failure.

The triaxial unloading tests of hard limestone are carried out. The mechanical properties changing with unloading stress path are studied. Five strength criteria are studied based on experimental results. Mohr-Coulomb criterion and Hoek-Brown criterion don?t describe the strength property of rock unloading failure. Drucker-Prager criterion and Mogi-Coulomb criterion fit experimental results very well. Mogi-Coulomb criterion fits experimental results better than Drucker-Prager criterion by comparison. The parabolic criterion is the best choice if the failure confining pressure is high. A rock unloading failure constitutive model is modified for describing the characteristic of volumetric strain. The theoretical model agrees well with experimental results.

An implicit integration algorithm of constitutive equations for multi-yield-surface model with non- associative flow rule is presented firstly. The yield criterions of multi-yield-surface model are gotten by fitting the experimental data through conventional triaxial tests and true triaxial tests based on generalized plasticity. The UMAT subroutine of this model is developed in ABAQUS with the FORTRAN language through the implicit algorithm. It is easy to verify the feasibility and accuracy of the model and the program by comparing the results of numerical simulation with that given by triaxial tests.

Sliding perturbation remote monitoring(SPRM) system has its unique advantages on the monitoring cost and effect，which had successfully forecasted landslide three times in the national scope. According to the principle and construction of system，combined with the early days application feedback，the existing defects and shortcomings were put forward，which were mainly concentrated on three aspects，such as，communications technology，data collection and transmission technology，forecast method and early warning mode of landslide disasters. The system was improved and finally upgraded to SPRM–III system，through using Beidou satellite communication system to replace the global system of mobile(GSM) network communication system，using ZigBee communication mode and wireless sensor network technology to develop and apply planar data collection and transmission technology，establishing standard forecast method and early warning mode of landslide disasters. After the completion of the improvement，the system began its engineering application. The application effect shows that the intrinsic problems and shortages have been overcome，the system working is stable and effective；and the expected goals have been achieved.

Using cement mortar as similar material，joint specimens with three joint wall strengths and five asperity angles were prepared. Then a series of cyclic shear tests are performed at four normal stresses on the cyclic shear test apparatus. Tests results show that，shear stress-shear displacement curve has peak strength of each shear cycle，and the shear strength of joints gradually decrease with the cyclic number increase. The peak shear strength of joint after n cycles is expressed as ，then the  = / is defined as shear strength ratio，so as to characterize the degree of strength deterioration under cyclic shear loads. Based on a variety of cyclic shear test results and  ，the relationships between peak shear strength of joints  and shear cycles are analyzed. By comparing the results under different experimental conditions，the effects of asperity angles，joint wall strength and normal stress on the joint mechanical properties are also analyzed.

Because of the stability problem of rock mass is very poor in the inlet and outlet section of tunnel，so some strong reinforcement measures should be applied；and the suspensory anchor-stake is one of these effective reinforcement methods. Firstly，the numerical simulation method and the mechanical parameters for suspensory anchor-stake are analyzed；then a simple case study for parameters sensitivity analysis of suspensory anchor-stake is carried out. The computing results show that，the results are influenced by the friction effect of grout is considered or not；so that，the rational simulation of grout is very important to the numerical simulation of suspensory anchor-stake. Finally，the numerical simulation of excavation and reinforcement of section 0+015 m of diversion tunnel #1 at the Nuozhadu hydropower station under different conditions is carried out；the interaction of rock mass and suspensory anchor-stake，the deformation of tunnel crown rock mass influenced by the suspensory anchor-stake are analyzed. The computing results show that，the subsidence deformation of tunnel crown rock mass is controlled by the suspensory anchor-stake effectively.

The extent of measurement range has a significant influence on estimation of trace length of discontinuity. However，measurement range is not considered in some of the current calculation formulas，though this parameter contained in some of the formulas，whether this influence could be showed in different measurement ranges still remain farther test and verify. So this paper attempts to make a comparative study on the basis of two types of data，one is created from Monte Carlo simulation，another is measured on a real outcrop. The influences of measurement range on the estimation of trace length by different formulas，the permitted minimum measurement range and its factors have been studied in this paper. The results indicate that some formulas may also contain notable errors when the sampling window is too large. Therefore，for the evaluation of the trace length of discontinuity，it should begin with the analysis of suitability and influence of measurement range；otherwise the sampling deviation would be still unquenchable even if complicated formulas are adopted. The edge effect and limitation of Monte Carlo simulation method for this issue have been found during this study. Also the suitability analysis in typical outcrops of candidate area for the geological disposal of high-level radioactive waste in China is made，which is helpful for the subsequent discontinuity investigation.

To eliminate the locating error for microseismic monitoring system due to the speed measurement deviation，three innovative nonlinear methods of multi-robe locating were proposed. According to different dependent variables，the source location methods of trigger times(TT)，time difference(TD)，and time difference quotient(TDQ) were proposed. The two traditional location methods with dependent variables of speed and trigger times(STT)，and speed and time difference(STD) were discussed. Firstly，virtual position tests，by the two new methods TT and TD and the traditional methods STT and STD in the floating rate of error at 0，1%，2%，3%，4% and 5% of the real sonic speed，were carried out using 8 sensors，respectively. The errors from two new and traditional methods were compared and analyzed. Results show that the errors of the absolute distance are 0–1.01339 and 0.01–0.014 m from new methods TT and TD without using speed；they are almost close to the 0–0.981 m from traditional methods STT and STD using real speed. However，it is very difficult to measure the speed in practice. There are more or less a certain measurement deviations，and we almost do not know its real value. Therefore，we consider the speed with a smaller error rates of 1%–5% floating，and they resulted in larger errors of source coordinate position；and the larger is up to 24.27 m. Secondly，with the signal of blasting effect as simulation source，the blasting experiments were carried out in Dongguashan copper mine；a deep-level mine in China. The results obtained by the innovative nonlinear methods TT and TD of multi-robe locating were compared with that by traditional methods STT and STD. It was proved that this new nonlinear method TD not only has better locating precision，but also it is more convenient than traditional method. To locate the seismic source by the new nonlinear method，only the times when the signals arrive at the probes need to be measured using the threshold crossing technique of the instrument；and the speed of the propagation medium needs no measurement.

The stability analysis of complicated block in jointed rock mass slope has been a critical concern in rock mechanics research of rock mass behaviors and engineering practice. There are some limitations in theory of classical limit equilibrium method(LEM) to this problem. In this paper，the formula for calculating safety factor of complicated block has been derived；and a relative specialty program has been compiled based on distinct element method(DEM). In contrast to LEM，there are no relative limitations to complicated geologic features，nonlinear behavior of rock mass and ground conditions. Two classical block failure problems have been performed to verify the rationality and correction of the program. Finally，the program is employed into the study of complicated block stability analysis of Baihetan hydropower station. The result shows the complicated block potential failure model and safety factor. Based on the calculation production above，some reinforcement suggestions are proposed for designers. The study in this paper advises certain point of view for stability analysis of complicated block.

A slope model with the geometric scale of 1∶8 was designed and a large-scale shaking table model test was performed to study the seismic displacement mode of anchor lattice frame structure and its characteristics under Wenchuan earthquake loading with three excitation directions including X，Z，and XZ direction respectively. The results show that：(1) Under X direction excitation，the seismic displacement mode of the proposed retaining structure is the translation from filling soil mass at the peak exciting acceleration AXmax≤0.4 g，the rotation inward or lower slope about the lower of retaining structure at AXmax = 0.6 g，and the coupling of the translation to filling soil mass and the rotation inward about the lower of retaining structure at AXmax≥0.8 g. (2) Under Z direction excitation，the seismic displacement mode of the proposed retaining structure is the coupling of the translation from filling soil mass and the rotation inward about the lower of retaining structure at AZmax≤0.267 g，the coupling of the translation to filling soil mass and the rotation inward about the lower of retaining structure at AZmax≥0.400 g. (3) Under XZ direction excitation，the seismic displacement mode of the proposed retaining structure is the coupling of the translation from filling soil mass and the rotation inward about the lower of retaining structure.

To study the physical meaning of strength meso-parameters of particle flow code(PFC)，based on equivalent meso-beam of contact-bond model(CBM)，tensional and shear states of two particles are analyzed. Relation between meso-stress of particles and fracture strength factors are derived. Then theoretical model between strength meso-parameters of PFC and fracture toughness of rock is established. There is a linear relationship between strength meso-parameters and fracture toughness. Besides，minimum radius and radius ratio of particle，especially the latter，have adverse effects on fracture strength factors of rock. Taking the sandstone of Chongqing for example，quantified expression between fracture toughness of rock and meso-parameters of PFC is established. The range of KIC calculated by meso-parameter of PFC fit the experimental data.

Based on ArcGIS Server with powerful spatial visualization and analysis tools of geographic information system(GIS)，as well as the SQL Server database，a network monitoring system that can be used in landslide hazards is introduced. In this system，based on studying the spatial and attribute data modeling and online visual query，the professional module which includes multi-view analysis methods：profile analysis，planar analysis and 3D (three-dimensional) analysis，is provided. Using this module，the functions of graphical expression，interpolation and trend analysis of monitoring information in section，plane and 3D view are achieved respectively. In all，the developed system implemented the needs of functions：the integration of spatial and attributes data，visual display and online inquiry，powerful spatial analysis，etc.；and it is extensively applicable. So it would play an important role in Web-based real-time monitoring data analysis and assessing safety condition of landslides as well as forecasting decision making.

Based on the investigation，test and numerical analysis of the mine dumps，it is believed that the key of disaccord between results from the 2D-LEM and reality is system spatial effect under the interaction of base and dump body. The spatial clamp effect of convex and divergent effect of concave are explained，as well as essential relationship between height and radius of curvature which should be abided by 2D or 3D stability analysis is given on the basis of field test，theoretical analysis and physical model. Furthermore，the safe class，evaluation criterion and technical route which takes the factor of stability as major and also considers stress，displacement fields and plastic region distribution is established，under the principle that the deformation and partial failure are allowable.

Four particle groups with different outlines are generated by the command of clump in PFC2D. Combining with deformation mechanism of granular materials，a shape coefficient is defined based on roundness and unevenness. The shape coefficient and friction coefficient are used to reflect the characteristics of particle outline and surface roughness respectively. The particle stacking test，biaxial test and direct shear test have been simulated with PFC2D，and how the shape of the particles affect the macro-mechanical properties of granular materials has been discussed. The results show that particle shape plays an important role in the macro-mechanical properties of these tests. In the particle stacking test，the natural angle of repose and natural porosity increases with the irregular outline of particles and the friction coefficient between particles. In the biaxial test，peak strength and shape coefficient can be fitted with linear functions well，and the internal friction angle increases with the decrease of shape coefficient. In the direct shear test，the shear strength of materials increases with the decrease of shape coefficient；the irregularity of particle shape also results in the decrease of strong force chain and the inhomogeneity of velocity field.

Natural hydraulic lime is extensively applied to protection and restoration of historic building. Based on the studies of conventional natural hydraulic lime(Yangshao cement)，we conducted experimental analysis of fundamental physical properties and environmental factors of calcinated Ginger nut and Aga soil，and compared to two European natural hydraulic limes(NHL2，NHL5). The results indicate that，Ginger nut and Aga soil burned calcinated at 1 000 ℃ for 3 hours had the similar characteristics to those of European water limes：less shrinking and deforming capacity，great interval porosity，good water and gas permeability，relatively stronger resistance to freeze thawing，stability in water，resistance to changes of temperature and humidity，and good resistance to erosion of alkaline medium；flexural strength and compressive strength of calculus body matched by materials of different ages tended to increase. The study results indicated that，after scientific modification，these two silicate materials applied to Chinese ancient buildings can be used in consolidation of historical relics made of stone and soil. The results have important significance on the spreading of traditional Chinese silicate materials.

This article summarized and analyzed the results of sand box test，simulated the seepage failure of the double-layer dike foundation. These experiments are focus on the affection of the different characteristics of simulated cover-materials on the seepage failure. Base on above analyzing，two criterions are derived. One is the stress strength，considering the seepage force. The other is the limited balance of the rotational moments of soil particle. Meanwhile according to the observed phenomena of experiments，the seepage failure is simulated by the two-dimensional axisymmetric finite element method(FEM). Compared the results between the experiment and numerical simulation，the above research method and two criterions on the seepage failure are reasonable，feasible.

Triaxial tests under constant suction are performed to study the shear characteristics under the control of matrix suction by using the unsaturated Yongdeng loess in Gansu province. Variation of matrix suction with water content and confining pressure and the relationship between matrix suction and suction strength are obtained. Besides a formula which can predict the contribution of different suctions to the shear strength of unsaturated loess is derived. The test results show：the matrix suction decreases with the increases of water content and confining pressure；while water content dominates the change of matrix suction. The suction strength is increasing with the increment of matrix suction and it is of high sensibility in the situation of low water content. This research provides a new method for the practical use of unsaturated loess shear strength in the western region loess engineering.

Based on the project of Shanghai metro line 11's side-crossing the St. Ignatius Cathedral，some helpful predications and deep analysis about long-term surface settlements have been presented by employing numerical simulation approaches and in-situ measurement techniques. Furthermore，the strengthening effects of MJS piles and the complicated influences of adjacent architectures are evaluated and calculated prudently. The computation results indicate that long-term surface settlement increases gradually over time and achieves stabilization ultimately. Due to the existence of MJS piles and adjacent buildings，the settlement trough significantly differs from traditional forms and performs a remarkable asymmetry. Particularly，it should be emphasized that those MJS piles effectively protect the surrounding region from large settlements and other harmful effects. The numerical simulation results and in-situ measurement data reveal a matching physical discipline；so the method of numerical simulation is validated scientifically and reasonably. Finally，several influences which contribute to the long-term settlement are analyzed：MJS pile reinforcement，building，disturbed region and creep parameters. Obviously，the achievement in this paper would provide a valuable reference for future similar projects.

Using the Laplace Transform，this paper analyzed the partially penetrated vertical drain with vacuum preloading. A three-dimensional virtual vertical drain is assumed to reflect the real three-dimension seepage in the soil beneath the tip of the vertical drain；moreover，the vacuum loss along the drain is also taken into consideration in the model. The parameters influencing the consolidation are analyzed，such as well-resistance，vacuum loss，the penetrating ratio etc.. Finally，the results are compared with the field data which are matched very well.