With the self-developed dynamic disturbance test system coupling with temperature and pressure，laboratory experiments were conducted to investigate the dynamic strength of siltstone under temperatures from 20℃ to 300 ℃ and different axial pressures. The effects of temperature and pressure on the dynamic strength of siltstone are discussed. The results show that：(1) When the temperature is 20 ℃–100 ℃，the dynamic peak strength of siltstone increases with the increase of temperature. However，the strength of siltstone decreases with the increase of temperature during the temperature over 100 ℃. (2) At the same temperature and different axial pressures，the dynamic strength of siltstone increases rapidly with the increase of axial pressure initially. When the axial pressure is up to 45 MPa，the dynamic strength decreases with the increase of axial pressure. And the higher the axial pressure is，the larger impact failure strength decrease is.

In order to achieve three-dimensional geological modeling and visualization of complicated high rock slope engineering，a new method of three-dimensional geological modeling and visualization based on data structures of half-edge B-Rep and trimmed NURBS is proposed. Through making comprehensive analysis of common data structure for describing the space topology in the field of computer graphics，rapid and accurate establishment of topological relation of three-dimensional geological model for rock slope engineering with complicated geological conditions and cavern groups is achieved；and the high-quality geometrical data and topological relation information for the geological visualization of slope engineering are provided. By analyzing the development trends of computer visualization technology and the characteristics of virtual reality technology，the feasibility of applying X3D specifications based on desktop virtual reality technology to achieve the slope geological visualization is demonstrated. According to the flexible scene interaction and support for the complicated NURBS geometric models of X3D，the real-time dynamic visualization of slope three-dimensional geological virtual reality scenes and visual interactive query in virtual reality scene objects based on X3D is realized. Finally，taking the left abutment slope of Jinping I hydropower station for example，the applications of three-dimensional geological visualization based on virtual reality to slope excavation progress simulation，geological prediction，visualization query of slope geological conditions，geological analysis of slope safety monitoring section，visualization query and integrated analysis of slope safety monitoring system and so on are given. These may provide reference for the application of three-dimensional geological visualization based on virtual reality to other engineering fields.

Based on the results of cyclicloading tests of two kinds of marbles T6 2y and T2b from Jinping II hydropower station，the elastoplastic coupling，strain-hardening and softening，shear dilatancy characteristics of rock are studied. Then，an elastoplastic coupling mechanical model is proposed with taking the following aspects into consideration：(1) A plastic internal variable which takes the influence of confining pressure into consideration is defined. (2) The variation of elastic parameters with plastic strain is concerned. (3) Based on the Mohr-Coulomb yield criterion，the evolution law of strength parameters during the plastic deformation is put forward. (4) The applicability of the generalized normality rule is validated and the method to handle shear dilatancy is proposed. The elatoplastic coupling model is embedded through the fast Lagrangian analysis of continua in three- dimension(FLAC3D) and is simulated by the triaxial compression test. The results show that the constitutive model can reflect properly the main mechanical characteristics of rock. Then，the unloading confining pressure tests are also simulated and the deformation and strength characteristics of marble are well obtained. The research results provide important reference to the understanding and analysis of yield process of brittle rock.

Utilizing the deep salt rock caverns to store the natural gas is the widely adopted method internationally. In order to study the influence of alternating pressure of gas injection and extraction and the gas pressure changing rate on the operation safety of storage，the three-dimensional gradient non-uniform loading geomechanical model test system，the gas injection and extraction intelligent control system and the bedded salt rock similitude material which is of significant rheological property are developed. Through the large scale three-dimensional geomechanical model test of gas injection and extraction for Jintan gas storage in Jiangsu province，the influence of risk factor such as the alternating gas pressure and the gas pressure changing rate on the operation safety of the storage have been got effectively. The test results show that the gas extraction-induced pressure release and the gas pressure changing rate are the important factors which affect the operation safety of the salt rock cavern；and the radial convergence displacement and radial strain increase gradually with the decreasing of the inner pressure of the cavern. The inner pressure value during the storage operation should be greater than 4MPa in order to ensure the operation safety of the cavern. The changing rate of radial displacement and radial strain surrounding the cavern get more rapid with the increasing of the gas injection and extraction changing rate. So，in order to ensure the operation safety of the cavern，the gas pressure changing rate of storage should be controlled effectively. The results of test research provide the reliable experimental evidence for the operation safety controlling of storage.

Based on prototype slopes in disaster areas of‘May 12’Wenchuan earthquake，two types of horizontally layered model slopes including hardness-upward and softness-upward are designed to perform the large-scale shaking table test with the geometric scale of 1∶100. Under the condition of similitude law，the seismic responses of model slopes are investigated with different input wave kinds，frequencies，excitation directions and amplitudes. Taking the situations of inputting acceleration amplitude of 0.3g as the typical example，the co-rotating acceleration dynamic responses of model slope with different lithology associations are analyzed under the single crude seismic load. The results show that the responses present obvious non-linearity along vertical and horizontal directions；and the elevation has amplification effect on seismic waves totally. Under the horizontal seismic load，the dynamic responses of slope appears mainly at the middle-upper part. However，with the equal input seismic load，the largest amplification of vertical acceleration is only one half of that of the horizontal acceleration；and the dynamic responses of slope appears mainly at the middle-lower part. The effects of different lithology associations on the acceleration response rules also vary with the different excitation directions. That is，under the horizontal seismic load，the hardness-upward slope demonstrates larger amplification effect of acceleration than the softness-upward slope basically；and under the vertical load，the result is opposite. Finally，by comparison of acceleration Fourier spectra in different elevations on the slope surface，the hardness-upward slope has obvious selectivity of predominant frequencies while the waves are propagating from the bottom；and for both model slopes，the predominant frequencies in vertical excitation concentrate on higher frequency ranges than those in horizontal excitation.

Aiming at the deformation and cracking phenomena of surrounding rock mass during the excavation of Jinping I hydropower station underground powerhouse under the conditions of high stress and low strength stress ratio，the characteristics and laws of in-situ stress field are studied entirely by the stereographic projection method and projection stress on typical planes. The deformation and cracking mechanism of surrounding rock of underground caverns group are deeply analyzed through mechanical qualitative analysis and 3D numerical simulation；and the damage evolution law of surrounding rock is studied. The results show that the relatively large deformation and cracking phenomena of surrounding rock and shotcrete layer of underground powerhouse are caused essentially by the adverse combination of the high ground stress and relatively low rock strength. The cracking failures in haunch，arch abutment and side wall of main powerhouse and main transformer chamber，and in side wall of busbar tunnels are typical unloading deformations and failures under the conditions of high stress，low strength stress ratio. The generalized model of surrounding rock deformation and cracking of underground powerhouse is presented. It affords important reference and qualitative basis for the back analysis of in-situ stress field and the numerical simulation of excavation process. Finally，some advices are given to maintain the stability of surrounding rock mass. All the results afford technical support to the construction and dynamic support design of the underground powerhouse.

The failure conditions of grades IV and V surrounding rocks in highway tunnel under different buried depths are studied through a number of model tests. The test simulation of failure process of non-supported tunnel under gravitational stress is carried out successfully；and two failure modes of arch collapse and caving collapse are obtained. The test results show that the failure of surrounding rock initiates from arch crown of tunnel and develops upward progressively. The smaller the buried depth is，the more likely the caving collapse occurs. When the buried depth is less than a certain value，the tunnel can maintain stability because the stress of surrounding rock induced by excavation does not exceed the strength of surrounding rock. For the caving collapse，the larger the buried depth is，the shorter the time of surrounding rock¢s stability is，the more serious the collapse degree is，and also the faster the collapse developing to ground surface is. For the same collapse type，the larger the buried depth is，the larger the changing amplitude of the stress of surrounding rock is.

According to the virtual work principle，a 3D discontinuous finite element method for the stress-strain analysis of dam/foundation system is presented. In this method，the complex domain for the whole system can be divided into two unconcerned subdomains：the subdomain of dam and the subdomain of foundation，the grids between which are mutually dependent. The discontinuous grids are coupled by using the geometric compatibility equations for the foundation surface deformation and element displacements of foundation and two sides of dam，the constitutive equations of foundation surface and the equilibrium equations of the whole system. An example of gravity dam on complicated foundation is studied by this method. The study results are in accordance with those from the general finite element method；and the precision and validity of this method is proved. Because the meshes of dam and foundation are independent from each other，the preprocessing of the proposed method is relatively simple and even the grids can be generated parallelly. The method can be widely used in the deformation and stability analysis of dams under complicated geological conditions.

Through the systematic analysis of basic features about International Society for Rock Mechanics(ISRM) suggested methods of rock mechanics laboratory tests and the structural level of test data，the basic idea and pattern of standardization are proposed to establish a standardization method system，a unified test data structure and a release format for laboratory tests. Then，the network language technology is used to design the digitized data structure document，data storage document and data display document. Based on the standardized data structure，a format conversion platform is developed to execute the digitized storage of initial test data document. The further development of Excel by visual basic for application(VBA) can implement the two-way transmission between utility software and digital storage document. The standardized and digitized data document can facilitate the integration of test data resources and the simultaneous updates of suggested methods. Besides，it has a good compression performance，a large data storage capacity and an advanced display format. With these superiorities，test data can be displayed and transported on web divorced from the platform. Thus，an international rock mechanics test data sharing platform is set up. This platform lays the foundation for the integration and sharing of data between different databases and the virtual laboratories. The successful application of standardization and digitization method to ISRM suggested methods of block punch strength index(BPI) test shows its scientificalness and availability.

The erosion situation，erosion rate and mechanical behavior rules of steel strands in anchors with time have been analyzed and studied through taking erosion tests in strong erosion condition on four types of anchors as steel strand and injection cavity defect anchor with or without prestressing separately. The mechanical behavior reduction of steel strands in anchors and the mechanical behavior reduction differences among various types of samples have been analyzed as well. The regression analysis of the variation of the fracture load of erosion anchor samples with time is conducted. The study results show that in the same erosion condition，the erosion rate of anchors with injection cavity defects(or with broken PE casings or bellows) is faster than steel strand，of course much faster than anchors without defects. Stress erosion has great effect on the mechanical behavior of steel strands in anchors. Based on various tests of the fracture load of steel strands in anchors with erosion time in different erosion conditions，the fracture load can be inferred in a certain erosion condition through the regression curves of relationship between fracture load and time for steel strands in anchors. Therefore，the safety assessment and life prediction to anchors can be carried out.

The crack evolution of lignite from 20 ℃ to 600 ℃ is studied by using micro-CT system intuitively. The extension and evolution of original cracks and new microcracks are discussed in detail. The study results show as follows：(1) From 20 ℃ to 100 ℃，thermal cracking degree of lignite is moderate and just a few new microcracks initiate. (2) From 100 ℃ to 300 ℃，thermal cracking is acute；many new microcracks initiate and original cracks extend quickly. The original and new cracks spread，overlap and connect with each other and finally form a crack network. (3) From 300 ℃ to 500 ℃，the extension of microcrack is very slowly. (4) From 500 ℃ to 600 ℃，some microcracks have trend of closure. With the increase in temperature，the microcracks initiate in soft coal along the bedding of coal seam and are arrested to hard coal；some cracks perpendicular to bedding direction will split on the edge of hard coal layer and then extend along the bedding of coal seam. The extension rate of cracks parallel to bedding direction is greater than that perpendicular to bedding direction.

In order to investigate the unique mechanical behavior of swelling deformation effect of coal induced by gas adsorption，the self-developed meso-mechanical testing apparatus of coal containing gas is used to perform the adsorbed swelling deformation test under different gas pressures. The results show as follows：(1) The swelling deformation and time curves of the same coal specimen under different gas pressures have the same variation law. The strain change rate of coal specimen decreases with time until it reaches a stable value. (2) The swelling deformation of coal specimen shows anisotropy. The total trends of strains perpendicular to the bedding and parallel to the bedding are consistence. Because crack distributions are different in the coal，the deformation perpendicular to the bedding is greater than that parallel to bedding. (3) The gas adsorption quantity of coal and its volumetric strain present a good linear relationship. Based on this，the swelling deformation equation is established considering temperature，moisture，ash，anisotropy and other factors. (4) Using the linear relationship between absorbed deformation stress and constrained deformation，and relationship of adsorption deformation and gas pressure，the calculation method of absorbed swelling stress is obtained. (5) The adsorbed swelling deformation of coal is irreversible；and the value of residual strain increases as the adsorbed gas pressure becomes larger. Swelling deformation effect of coal induced by gas adsorption is important for engineering application. It can be used as an assistant index of coal seam outburst risk assessment，and also can be used in gas permeability study of coal seam.

Structure damages caused by blasting vibration are not only related to the vibration intensity，but also related to vibration frequency，duration and other factors. The safety evaluation index based on independent threshold value may be inconsistent with the actual damage. Thus，it has important significance of establishing the safety evaluation index of blasting vibration from the energy viewpoint. The instantaneous energy analysis method based on Hilbert-Huang transform (HHT) is proposed. Firstly，intrinsic mode function(IMF) components of blasting vibration signals are extracted. Then，Hilbert transform for IMF is gotten to calculate the total input energy(TIE) of vibration signals. Finally，TIE is used as safety evaluation index of blasting vibration. TIE value not only can reflect the general laws of particle peak velocity(PPV) based on existing specification，but also can give a concise quantitative description for dominant frequency and duration factors. Combining the measured blasting vibration data of shallow-buried section in the Qiantangjiang diversion tunnel project，the feasibility of this method is verified. According to example calculation and blasting damage investigation，the blasting vibration will harm masonry structures when TIE is greater than 1.

The self-made analysis system of three-dimensional(3D) visualization，named SlopeMoni3D and developed for safety monitoring of rock slope engineering，is used to establish safety monitoring distributed analysis platform for the left bank high slope of Jinping I hydropower station；then the virtual reality visual analysis of the safety monitoring system and occurrence of slope geological conditions is realized. The development tendency of superficial，deep deformation and the spatial distribution of anchoring force of cable dynamometers at the same period in the excavation area of the left bank slope，which is obtained by safety monitoring，are comprehensively analyzed in the form of three-dimensional nephogram visualization. The analysis and evaluation of overall slope stability and deformation tendency are completed. The analysis results indicate that：(1) Using virtual reality visualization technology to resolve regional engineering geological conditions of complicated rock slope，we can directly express the relationship between monitoring points arrangement of each monitoring project and its geological structures and easily realize the comprehensive analysis based on monitoring results，geological conditions and construction information. (2) By virtue of the functions of monitoring data management and 3D nephogram rendering based on monitoring data fields，which are provided by SlopeMoni3D，we can directly compare the 3D nephogram distribution of obtained monitoring physical quantities of different monitoring projects at the same monitoring period；and it is convenient for analyzing the regional deformation tendency and overall stability status from various aspects of geology and construction.

The gray sandstone from disaster area of extreme ice and snow in early 2008 is selected to make the combined specimen with gray sandstone and C20 shotcrete. Through different kinds of tests，i.e. freezing-thawing cycling test，uniaxial compression test，triaxial compression test under medium and low confining pressures，direct shear test under medium and low axial pressures，micro-scanning test，the macroscopic physico-mechanical properties of combined specimen with rock and shotcrete and its micro-damage mechanism are both studied systematically. The test results reveal the damage mode，failure criterion and variation of strength indices of the combined specimen with different water contents(dried or saturated) after different freezing-thawing cycles. Based on the above results，the damage softening statistical constitutive models for combined specimen with rock and shotcrete before and after freezing-thawing are established. By contrast with the curves of triaxial compression test，the new damage softening statistical constitutive models can truly reflect the entire damage process and the models are considered to be reliable.

The study of rock breaking efficiency by rolling cutters mainly focuses on laboratory linear cutting experiment and numerical simulation analysis. Tunnel boring machine(TBM) penetration test is not popularly conducted in project sites. Three TBMs are used to respectively excavate the headrace tunnel #1，#3 and the construction drainage tunnel in Jinping II hydropower station. The TBM penetration tests，the sieve tests of the rock chips and big chip statistical analysis are carried out respectively in these three tunnels under different tunnel buried depths(namely different geostresses). The influences of engineering-geological conditions，TBM parameters and TBM operation parameters on TBM penetration rate and the variation in rock mass boreability index under high geostress are analyzed. The analysis results show that under high geostress，although the penetration rate of TBM increases with increasing thrust force，TBM does not operate in optimal state while the thrust force is larger than a specific value. TBM operation should match with the conditions of rock mass and geostress.

A certain proportion of quartz sand is added to pure bentonite in deep geological disposal project of high-level radioactive wastes(HLW) to optimize the thermal conductivity and constructability of buffer/backfill materials. Proceeding from the concept of composite soil，the compacted bentonite-sand mixture specimens with the same dry density，water content and different sand ratios are designed to reveal the controlling mechanism of sand ratio to shear strength by shear test. Gaomiaozi bentonite from Inner Mongolia(GMZ001 bentonite)，mixes with quartz sand in a weight ratio of 0%–50%，is selected as test specimens. The shear test results indicate that，with an increase in sand ratio from 0% to 50%，the compacted mixtures yield a shear behavior from strain-softening to strain-hardening；and the cohesion and internal friction angle decrease correspondingly，which means that the shear strength decreases. Based on a pore structure hypothesis，according to analogy analysis，the bounded sand ratio governing the shear behavior of clay-sand mixture are estimated from the published data；and the supporting scanning electron microscope(SEM) pictures of pore structure are provided. By introducing the effective clay density and effective water content，the physical states of clay matrix among quartz sand particles is described，the controlling mechanism of quartz sand content to the shear strength of bentonite-sand mixtures as buffer/backfill material is reasonably explained.

The load sharing law of composite embankment with long and short piles under embankment load is studied through centrifuge tests and three-dimensional finite element methods. Four centrifuge model tests are conducted on the purpose of exploring the variation curves of pile-soil stress ratios of long pile and short pile with a given length ratio of pile in stepped loading process. The relationship between the axial forces of long pile and short pile measured in each test and the settlement of soft soil is conducted. Based on the fundamental parameters of the centrifuge model tests，three-dimensional finite element models are established to carry out the comparison with the centrifuge tests results. The Gibson subgrade is adopted to factually simulate the strength feature of soft clay foundation in the centrifuge field，which gradually increases with depth as closer to the bottom of the test box. Comparison of the calculated results with measured centrifugal model test results identifies the rationality of the established model. Furthermore，the pile-soil load sharing law of this composite embankment with long and short piles which is applied to the layered foundation with bearing stratum is studied through this numerical method. The study results show that the long piles take more embankment load with the increase of embankment load，while the short piles and soft soils both take less and trend to be stable. The larger the length ratio of long pile to short pile，the more the load sharing ratio of the long piles take. The composite embankment with long and short piles is better in reducing embankment settlement and the long piles shares more loads in the layered foundation with bearing stratum.

In the soft soil areas，bursting induced by confined water is the most important factor which affects the safety and stability of deep foundation pit，and is the key technological problem of design and construction which is urgently solved. The influence of different impermeable layer types，pile types and the layouts of piles on the bursting stability and failure modes of foundation pit are studied systematically by centrifugal model test. The test results show that the failure modes of foundation pits bursting in soft soil areas can be mainly divided into three kinds，i.e. water and sand inrushing in contact surface between soil and underground structures，overall heaving failure and sand boiling on impermeable layer surface. Based on theoretical analysis，the internal mechanisms of bursting in foundation pits are cleared respectively that the contact surface between impermeable-layer and underground structures occurs hydraulic fracturing，contact surface or nearby occurs shear failure and impermeable layer occurs complex tensile-shear failure and shear failure.

Consolidated-undrained shear tests of rotation of principal stress axes are carried out on Hangzhou intact soft clay with hollow cylinder torsion shear apparatus(ZJU-HCA). The influence of shear stress change，initial shear stress level and both positive and inverse rotation of principal stress axes on characteristics of pore water pressure  development clay are discussed. In the tests，the mean principal stress is kept constant and the intermediate principal stress coefficient is set to 0.5. The test results show that the pore water pressure in fixed shear period is mainly controlled by shear stress. The pore water pressure coefficient is acquired by double yield surface theory，which is combined with linear fitting results of pore water pressure to reveal that the volume yield surface function is not affected by the rotation of principal stress axes when initial shear stress is below the peak shear stress. If the initial shear stress is close to the peak shear stress，a relatively high velocity of pore water pressure is generated at the beginning of rotation，but later pore water pressure decreases. The corresponding velocity of pore water pressure in the rotation process of pure principal stress axes is mainly dominated by initial shear stress. The pore water pressure under positive rotation of principal stress axes is smaller than that under inverse rotation. The influence of inverse rotation of principal stress axes on pore water pressure is larger than that of positive rotation through the whole shearing process.

Based on the uplift static test of grouted and non-grouted uplift piles at a building site of Xiaoshan in Hangzhou area，it¢s found that pile-end post grouting technology can significantly reduce the pile tip settlement and increase the ultimate uplift resistance of pile. The ultimate uplift resistance of the pile with post-grouted is 1.25 times of the pile without post-grouted and the maximum tension value of pile shaft is about 91.5% of the displacement at the pile head. The axial forces of grouted pile shaft and non-grouted pile shaft both decrease gradually with depth and the measured end axial forces of piles are near zero during the whole loading cycle. The friction resistance of grouted pile within the climb height of grouts of 16.9 m has a large increase and the maximum value is 83.3%，because the mudcake near the pile end is solidified by grouting and the larger friction resistance are mobilized. Based on the vertical enhancement body height of grouted uplift piles calculated by the formula of climb height of grouts，a new simple formulation for calculating the ultimate bearing capacity of uplift piles with pile-end post grouting is proposed by considering dead weight of piles. Through the back analysis and calculation，it is shown that the value range of the uplift reduction coefficients of non-grouted piles is 0.65–0.80；and the value range of lateral resistance enhancement coefficients of grouted piles is 1.33–1.83. The calculation method and its results can be applied to the preliminary design and practical engineering.

Based on the previous theoretical analysis and the systematic analysis of field pull-out test data，the influence of anchorage length，pull-out load as well as cable diameter on the load transfer law of the prestressed cable under the specific condition of loess stratum are analyzed. The analysis results show that：(1) The most rational effective anchorage length of prestressed cable is 6–8 m. The ultimate bearing capacity of the prestressed cable can not fully be exerted when the anchoring segment is too short；and the prestressed cable is easy to be wasted under the condition that the anchoring segment is too long. (2) The axial force of cable continues to transfer the remote anchorage section getting smaller and smaller whose peak value grows and shifts to the remote with the increase of the pull-out load，which is associated with the fact that the axial force of the front anchorage segment produces local plastic damage when the pull-out load exceeds the anchor¢s ultimate tensile strengths. (3) Soil mass and anchoring body have significant heterogeneity and nonlinearity，which results in being of the relatively weak or noncontinuous interfaces between grout and soil. The distribution of the anchorage force on the weak plane discretes jump while the pull-out load increases to a certain level. (4) In engineering practice，the starting points of anchoring force distribution curves do not overlap with the port anchor absolutely but deviate from the relative vertical axis to varying degrees，which makes the actual length of anchor is usually shorter than the theoretical design length. (5) Under the loess stratum，the ultimate capacity of some prestressed cables increases linearly with their diameters increase，independent to the effective anchorage length. The growth factor is about 1.1. These conclusions with some theoretical and practical values provide a reference for the design and construction of anchor support engineering in the loess region.

Mononobe-Okabe formula is widely used in lateral seismic earth pressure calculation in the design of retaining walls. However，application scope of Mononobe-Okabe formula is strictly limited because of too many assumptions. The distribution of seismic earth pressure strength along the back of retaining wall and the position of application point of resultant force of seismic earth pressure can¢t be obtained. In order to compensate above shortcomings，based on planar rupture surface assumption of Mononobe-Okabe theory，horizontal slices analysis method is suggested to deduce analytical formulas of resultant force of seismic earth pressure，application position of resultant force and distribution of seismic earth pressure；and the explicit solution of critical rupture angle is obtained by graphic method. The influencing factors including horizontal and vertical seismic accelerations，batter angle of wall back，cohesion and external friction angle between filler and back of retaining wall，equispaced overloading are considered. The formulas can be used for seismic active and passive earth pressure calculations of cohesive soil or non-cohesive soil. The analysis results show that the distribution of seismic earth pressure strength along the back of retaining wall is nonlinear. The formula is the same as Mononobe-Okabe formula under corresponding simplified assumptions.