Viscosity of grouts is an important factor in grouting which is the main method in groundwater governance. Research on time-dependent behavior of viscosity is very necessary. Laboratory tests were performed and the data was analyzed. Viscosity and temperature were measured using vibrating type viscometer for two fast curing grouts，cement-sodium silicate and polymer modified cement grout. Variation of viscosity and temperature with different water-cement ratios and volume mixing ratios of the grouts were analyzed. Reaction progress was classified to three periods according for viscosity behavior. Data fitting was done with viscosity of grouts measured，and equations of time-dependent viscosity were obtained. Adapation of different fast curing grouts was discussed. 

The underground powerhouse cavern groups at Xiluodu hydropower station in Jinsha river has huge scale and complex structure. The discontinuity of rock mass induced by the disturbed belts between bedding and inner bedding is the main geologic problem. The elastoplastic damage theory is used to analyze the stability of surrounding rock；and the excavation sequence and supporting parameters for underground caverns are determined. Based on meticulous construction organization，the extent of damage to surrounding rock is strictly controlled to ensure good forming of caverns outline. Real-time analysis and inversion analysis of monitoring data are conducted；and the dynamic design for supporting workload is needed. In the process of excavation，the displacement and stress have a good change regularity. After excavation，the measured values of displacement and stress is relatively small；and the surrounding rock of underground powerhouse caverns has a good stability. The scale of underground powerhouse caverns at Xiluodu hydropower station tops the list in China. The summary from control measures for rock mass engineering such as design，excavation and support，monitoring data analysis and inversion analysis，can provide some references for the similar projects.

Based on a series of microscopic mechanical tests on the bonded granules idealized by two glued aluminum rods，a microscopic bond contact model for rocks was proposed and implemented into a commercial distinct element code. The customized code was then used to simulate the uniaxial and biaxial compression tests，the direct tension test and the Brazilian test on rock. The numerical results were compared with available experimental data to verify the bond contact model. The results demonstrate that the distinct element method incorporated with the proposed model can capture the fundamental mechanical behaviors of rocks. The relationship curve between the bond broken number of bonds and the axial stress can be used to distinguish different stages of crack propagation and to predict the crack initiation stress，the crack damage stress and the peak stress.

In the stability analysis of rock wedge，judgment for sliding modes of the wedge is very important for stability assessment of rock slope and design of excavation and support schemes. This paper discusses the problem of sliding modes of the wedges and analyzes the causes of resulting in false sliding modes in Hoek-Bray method. An improved method for wedge stability analysis is proposed by employing the kinematical conditions for wedge failures to modify Hoek-Bray method. Considering the scatter in the dip and dip direction measurements，one set or two sets of discontinuities forming the wedges are not determined. This paper developed an optimal approach for undetermined wedge blocks，in which the genetic algorithm is used to locate the critical sliding surfaces and search for the wedge which has the minimum factor of safety. The method provides a lower bound solution with conservative advantage and the stability of rock slope can be assured.

Using self-made meso-shear test equipment for gas-containing coal and rock，the researchs on the evolution process of cracking and development，macroscopic crack morphology，and meso-crack coalescence mode of raw coal containing horizontal and vertical surface cracks，are carried out under different loading speed conditions. Results show that horizontal surface crack influenced the numbers of macrocrack development，made macroscopic shear crack morphology of raw coal containing horizontal crack manifested H or H+L type；while，vertical surface crack had no effect on the number of macroscopic crack development；raw coal containing vertical crack showed L type. Effects of original cracks on the development and evolution of the new crack were limited to the local area near predetermined shear plane，cracks far from predetermined shear plane and rock samples defects far from predetermined shear plane induced by making of raw coal samples，whose shape were not changed significantly，had no significant effect on the macroscopic crack development near shear plane. Nearby predetermined shear plane，later macro main crack will cause pre-generated right side crack closed. Vertical original crack on the left side of the shear plane had no effect on crack initiation and expansion of macro main crack. Meso-analysis show that，horizontal surface original crack made coal rock failure mode complex and diversification，including compressed failure，shear failure，tension failure，and combination mode，lead crack initiation location to appear at the original crack nearby predetermined shear plane，while vertical surface original cracks less affected the coal rock failure mode.

The deformation rules and strength characteristics of sandstone samples in the process of Brazilian split fatigue load were studied by the RMT–150B multi-function servo system. The results showed that there were almost same deformation characteristics in both the conventional split test and uniaxial compression test before the peak load，which could also be divided into 4 stages including compression，elasticity，yielding and failure stage. The destroy mode of Brazilian split fatigue was controlled completely by the fracture process curve of the conventional Brazilian split；and the deformation value and upper limit load(stress) were equivalent to the corresponding deformation in the post-peak process curve of the conventional Brazilian split test. The deformation(rate) curve versus time in the process of splitting fatigue test was similar to the creep characteristics curve，which could be divided into 3 stages including initial acceleration，constant velocity and acceleration stage；and the fatigue limit load(stress) ratio and the tensile fatigue strength were negatively correlated with the cycle number. The fatigue upper limit load(stress) was the main control factor impacting the rock fatigue life；and the internal original microcrack distribution of sandstone sample had great influences on the split fatigue life. The increase of the upper fatigue limit load(stress) leaded to reductions in fatigue life；while the tensile deformation basically unchanged.

Due to the limited size of model box，the centrifuge model can?t meet the requirement of semi-infinite body in situ experiment，which forms the boundary effects. This problem is especially prominent in blast centrifuge modeling. Relying on Tsinghua University 50 g-t geotechnical centrifuge，several blast centrifuge model tests have been done to select appropriate boundary material by analyzing the accelerating field. The results within 20 cm from the explosion center can be accepted under the conditions of acceleration 50 g，explosion 2.5 g after adding the material in boundary.

The deformation and failure characteristics of brittle-ductile-plastic transition，which is shown in the post-peak stage for Jinping deep marble，was simulated by clumped-particle model(CPM) of particle flow code(PFC)，and studied from the micro view. After a long process of trial-and-error calibration of laboratory test results，a set of micro parameters for Jinping deep marble were obtained. It is shown that a series of macroscopic mechanical properties of the synthetic rock，including the elastic modulus，Poisson?s ratio，uniaxial compressive and crack initiation strengths，stress-strain curves，the peak and residual strength envelops，the ratio of tensile to uniaxial compressive strength，and the failure patterns of synthetic rock samples，all agree well with the test results of Jinping deep marble. Study of regularities of crack development in synthetic rock samples at different confining pressures indicates that：The significant difference of development features of microcracks at different confining pressures is the main reason which leads to Jinping deep marble appearing brittle-ductile-plastic transition character；and the development of large number of tension cracks determines the brittle failure pattern of medium，while the rapid growth of shear cracks prompts the failure patterns of medium transition from brittle to ductile or plastic.

Power ultrasonic incentive promoting desorption of methane in coal seam is a kind of general applicable value technology，which is out of limit controlled by reservoir geologic conditions and source gas characteristics. Through CT observation and promoting desorption experiment，the rule of coal samples different scales fracture development is analyzed considering ultrasonic effect，from microscopy to reveal the power ultrasonic promoting desorption mechanism. In contrast to the experimental determination of promoting desorption results，the rule of gas desorption quantity in coal sample changing with time by power ultrasonic action is studied. Research results show that：CT observation is the good proof that the ultrasonic mechanical shatter role. In the power ultrasonic incentive effect，the number of coal sample fracture significantly increased；transfixion crack increased and a single crack maximum width increased significantly；methane desorption quantity of coal has increased dramatically by ultrasonic incentive；the modifier formula of ultrasound promoting methane desorption quantity changing with time in the coal is established. The fitting correction formula show that：gas desorption quantity   and   increased with increasing pore pressure after saturated adsorption；the methane saturated adsorption desorption quantity is greater than the desorption quantity  without ultrasonic incentive in same pore pressure；the reason is that in the influence of power ultrasonic field strength，coal point of kinetic energy and potential energy increase，the coal surface even matrix internal adsorption of methane easier to stripping into determination of free，so as to achieve coal seam methane promoting desorption effect.

The study has developed a laboratory test to simulate the excavation，supporting and deterioration  process of primary support of the deep hard rock tunnel. In the paper，variation rules of displacement，load and internal force of the secondary lining in the deterioration process of primary support are analyzed. The study proves that in the primary support deterioration period or even in the failure process，there are different effects between the shotcrete and the bolts. The effect of the bolts，which has step characteristics，is much more obvious than that of the shotcrete. The increasing trends of displacement，load and internal forces are all firstly rising up slowly and then accelerating，finally becoming steady. In the vault and side walls，such mechanical phenomenon is typical. After calculation of the lining security，we found that the safety extent is satisfied. The design is relatively conservatory.

2.5D finite element equation for elastic waves of transversely isotropic soil is derived from means of 2.5D finite element method(FEM) from elastic constitutive equation of the transversely isotropic soil. The track is simplified as an Euler beam resting on the transversely isotropic ground. Through finite element discretization，the track structure and the foundation in a section perpendicular to track direction are modeled with 8-node elements，in which each node consists of three degrees of freedom. A 3D problem is reduced to a plane strain problem；and the results can be obtained by inverse fast Fourier transformation(FFT). Dynamic responses of the ground are analyzed based on typical parameters of soil in Shanghai and Beijing areas. The results indicate that the amplitude of acceleration and displacement response amplitude caused by train traveling in Beijing area were higher than that in Shanghai area，respectively. With the distance increase to the track center，dynamic response frequencies of the ground in both areas are declined to the free vibration frequency of simple harmonic vibration；so the filtering of transversely isotropic soil is obvious. Transmission of dynamic wave in soft soil layer costs more energy than hard soil. The rebound phenomenon in the attenuation curve of the ground vibration has the tendency to increase，which is closely relevant to the parameters of the soil and the train speed.

The comparative experimental research on point load strength，uniaxial compressive strength and tensile strength of rocks in the roof and floor of coal seam was carried out by the self-made point load tester to obtain a quick and accurate method to predict uniaxial compressive strength and tensile strength through point load strength. The results show that the samples of coarse stone with lower point load strength are greatly influenced by loading rate and loading direction；so the errors of the predictive values and actual values are quite large. For the rock samples with larger point load strength，their linear correlations are higher among strengths of three types. It provides an important basis for the determination of rock strength and rock mass classification in the roof-floor of coal seam.

Two groups of in-situ tests with two testing piles in each group，which were part of testing engineering for Hong Kong-Zhuhai-Macao Bridge in China，were finished by Tomer-cell method(self-balanced method called in China). The side frictions of the testing piles in moderate weathered granite were analyzed by observing the axial force and the moving of pile toe，pile top and the pile section at top of moderate weathered granite during applying static axial compressive load through a group of jacks located in certain section in moderate weathered granite. The rock strength and integration level in location of each group were different but the load-settlement curve of each pile was all like a sudden-falling one. For the piles in the group located in broken rocks with lower strength，the side frictions of piles above the jacks were less than those under the jacks；but the side frictions of piles above and under the jacks were nearly the same for the other group located in little broken rocks with higher strength. The ratio of side friction to rock strength was higher when the rock strength was greater for the pile section above the jacks，but for the pile section under the jacks，such ratio was lower.

A limit equilibrium method that satisfies the three force equilibrium conditions of all columns and three moment equilibrium conditions of total failure mass is proposed，in which the interslice forces are assumed by proposed lateral shear factors and lateral shear distribution functions. The present formulation can be treated as an extension of the 2D Morgenstern-Price? technique. The factor of safety of each row(column) is obtained by solving the force equilibrium equations and the boundary conditions of total failure；then the lateral shear factors are determined by solving the torque-equilibrium equations for total failure mass. All intercolumn forces are taken into account in calculating factor of safety. The direct iterative algorithm is implemented in the program developed by the authors to improve the computational efficiency markedly. The analysis results for two examples indicate that the given ?1，?3，?4 have a small effect on the factor of safety for symmetrical slope and the given ?4 also has a slight effect on the factor of safety for asymmetric slope；and these factors of safety obtained in the new formulation are similar to those in previous studies. It is not necessarily true for some composite slip surfaces that a more simplified formulation will give a lower factor of safety.

Taking ADINA for example，based on external program and native constitutive model secondary development program，it is put forward that the static analysis module，frequency analysis module and seismic analysis module can be united called and data is transferred among these modules to realize the automatic finely calculation for static and seismic analysis of earth rockfill dam. External program is developed only towards the function which can?t be realized with ADINA?s user-supplied program. A classical calculation example in famous seismic analysis software SHAKE91 is analyzed with the suggested method. The results of comparative analysis and seismic safety study of a high earth rockfill dam show that the method suggested is high efficient，easily programmed and reasonable. This method can be similarly applied to the development of ANSYS，ABAQUS and other finite element softwares to make up for their lack of solving certain programs.

The laboratory tests are made for studying characteristics of acoustic emission(AE) of granite from Linyi in Shandong province at 20℃ to 800℃ using hydraulic-pressure servo testing system MTS810 and acoustic emission instrument AE21C. The relationship between ringdown count rate of granite and time as well as the relationship between AE parameters and stress-strain curves due to uniaxial compression loading are analyzed under different temperatures. Studies have shown that ringdown count rate rises and AE activity becomes more frequent with temperature increases both in the processes of heating and loading. AE parameters are quite different at and after the high temperature，of which AE parameters after high temperature are significantly lower than that at high temperature；and internal cracks are fewer resulting in that mechanical properties at high temperature are superior to that after high temperature. Ringdown cumulative count of granite at high temperature is higher than that after high temperature；especially at 800 ℃ when there is more than a doubled difference. The high temperature causes a significant increase in energy and accelerating the energy dissipation. The granite specimens showed brittle failure such as splitting and shear failure which did not appear strong ductile failure. The strength of the rock decreases and macroscopic cracks increase due to energy dissipation and elastic energy release which eventually cause deformation and failure of granite.

The behavior impacting failure and dynamic mechanical properties of granite exposed to high temperature have been researched with high-temperature split Hopskinson pressure bar(SHPB) system and ultrasonic detector SRM–5N. The scope of this research includes the variation of longitudinal wave velocity，waveform，dynamic compressive strength and peak stress with the temperature. The temperature varies in the range of 25 ℃，100 ℃，200 ℃，400 ℃，600 ℃，800 ℃，1 000 ℃，and the heating velocity is 10 ℃/min. The results are as follow：(1) Generally speaking，the thermal damage of granite gradually raises with the temperature increasing. But it decreases before 100 ℃，Then enhancement of thermal damage is not drop slowly until exposed to 600 ℃. (2) As a whole，the dynamic compressive strength of granite is diminution and peak strain is enlarge when the temperature is enhanced，but it is opposition with them before 110 ℃. And dynamic compressive strength is obviously reductive and peak strain is obviously enhancive after 600 ℃. (3) It is suggested that 110 ℃ is a temperature threshold of granite，before this temperature，the thermal damage of granite is minus，the dynamic compressive strength decreases. And suggested another temperature threshold is 600 ℃– 800 ℃，the dynamic mechanical properties of granite changed obviously beyond this temperature. The research method and conclusions can provide references for rock project construction and fireproofing designs.

Geological strength index(GSI) is an important parameter of Hoek-Brown criterion. However，there are not any typically measurable parameters during determination of GSI，which leads to the highly subjective value of GSI. Based on the study of rock mass of detailed geotechnical investigation in the region where is abundant of gneiss，the authors propose that a quantitative analysis method should be used to GSI，according to the parameters such as rock core length(RCL) and Jc，and trying to utilize the photos of the intact core in the field site to substitute the sketch of rock mass structure in GSI，Ultimately，the authors set up a new generalized GSI. In terms of the contrast of calculation of ultimate bearing capacity for rock foundation by the authors and the values given by the unit of investigation，the authors find that the results fit well and the precision is high，which means it is scientific of these charts.   

The cement can not hydrate sufficiently and uniformly at low temperature，so it?s easy to arouse rise the problem with lack of strength and appearing penetration cracks for tunnel concrete lining in cold regions during winter. According to the temperature control equation including low temperature phase transition，beginning with the study of influence of excavation time on temperature distribution of surrounding rock，considering the heat of hydration of concrete，the heat transfer law between surrounding rock and concrete lining was analyzed，and the influence of environment temperature in tunnel，heating temperature and time on the change rule of concrete temperature was studied. The results show that the influence scope of environmental temperature on the temperature of surrounding rock increased with the increase of excavation time；after a period of heated time，the temperature of surface and deep surrounding rock became higher than the middle?s，formed a temperature distribution of hot at two head，cold in the middle；the lowest temperature of concrete lining in 24 hours increased with increasing of heating time，heating temperature and environmental temperature. Based on this，a concise and practical heating time calculation formula was put forward. The in-situ results show that the goals were realized about the lining concrete can continuously and efficiently constructing，its surface has no crack and the actual strength＞C30 by applying the proposed calculation formula.

In order to study the applicability of the response deformation method in the seismic analysis of the underground structure，the basic principle is verified by the theoretical analysis based on the substructure method and soil-structure dynamic interaction method. The specific application forms used in engineering applications and design criterions are described. Different computing models and soil spring coefficients were analyzed. In order to verify the efficiency of response deformation method with different forms，the methods of response deformation and soil-structure dynamic interaction are applied to calculate the Dakai subway station structure. The numerical results show that the classic response deformation method is more practical.

Argillaceous shale is a very common rock that when in contact with water can show considerable volume change and breakdown. The behaviour of argillaceous shale is frequently encountered in geotechnical engineering and has a considerable influence on infrastructure stability. This is particularly important in the present work，which focuses on improving the harmful properties of argillaceous shale. The samples studied are of Permian Age argillaceous shale from the Shandong province，China，modified tests by organic silicon material were carried out. The change rules of surface hydrophobic property，porosity and fracture，swelling and shrinkage，microstructure and physico-mechanical properties of argillaceous rock were comparative researched by static water contact angle method，nitrogen adsorption isotherm method，free swell test，SEM-EDS analysis and conventional rock mechanics strength test respectively；and modification mechanism of organic silicon material modified argillaceous rock is analyzed. Results show that：(1) The surface texture and characters of argillaceous rock changed dramatically for modified，the contact angle of water drops on the rock sample surface increases from 8.51°to 113.34°，surface character turns from hydrophilic to hydrophobic. (2) The shape of porosity and fracture of argillaceous rock changed unremarkable，and the total decreased obviously for modified，nitrogen adsorption decreased from 26.488 2 cm3/g to 9.477 3 cm3/g，BET surface area decreased from 13.029 8 m2/g to 2.856 4 m2/g，and the maximum pore size decreased from 150 nm to 110 nm or so. (3) Free expansion ratio of argillaceous rock decreased from 3.54% to 0.51%. (4) The chemical element composition of argillaceous rock altered largely，and carbon element increased and sulfur element found for modified indicated organic silicon material infiltrated rock inward. (5) Strength of rock increased obviously for modified，uniaxial compressive strength increased from 9.3 MPa to 26.05 MPa；tensile strength increased from 1.69 MPa to 3.22 MPa.

Through the analysis of stress state of the soil plug，the condition of generating squeezing effect and squeezing mechanism for the process of jacked-in steel pipe is analyzed. The results show that：the condition of generating squeezing effect is that the stress at the bottom of the soil plug is greater than the bearing capacity of foundation at the end of the steel pipe；the jacked-in steel pipe can be regarded as displacement pile，non-displacement pile and incomplete displacement pile according to the relevance of the stress at the bottom of the soil plug and the bearing capacity of foundation；the extruding ratio can be used as the assessing index for the squeezing degree of the incomplete displacement pile. Besides，theoretical calculating methods for the stress at the bottom of the soil plug and bearing capacity of foundation at the end of the steel pipe have been analyzed and summarized. At last，through the measured data and implement result of the construction of the protective steel pipe for the bored pile，the rationality and practical applicability of the theoretical analysis for the jacked-in steel pipe have been demonstrated.

The single pile is always loaded by the vertical，lateral and moment loads，rather than a single one and the bearing capacity of single pile is affected by the interaction among them. In order to study the behavior of lateral bearing capacity of single pile as different vertical and moment loads were applied on single pile before the lateral one，the special device for combined loads was designed and a series of model tests in sand were conducted to investigate the effects of vertical and moment load on the lateral pile top deflections，pile top rotation angle，bending moment and ground coefficient. For the piles under the vertical load less than Vu/2，the presence of vertical load improves the lateral bearing property of single pile，and lateral displacement and the maximum bending moment in pile decrease with the increasing of vertical load. However，the bending moment acted on the top of pile is harm to the lateral bearing property and the ultimate lateral bearing capacity is significantly deteriorated. The settlement is affected slightly by the lateral load when the vertical load is loaded previously. The ground coefficient decreases rapidly as the lateral deformation increases when the lateral deformation is small，and then decreases slowly and tends to be a constant value as the lateral deformation grows.

The measured data from soil stressometer located in dam and achievements of previous researchers both showed that the stress path of rockfill during filling period is close to constant stress ratio state. This rule will not change because of the complicate material partition and construction stages. The stress path influences the deformation properties of rockfill in greater degree. The constitutive models and corresponding parameters obtained under the conventional triaxial experiments path may not play its role correctly for the real dam stress path. From the characters of stress-strain of Nuozhadu，Shuibuya and Sanbanxi rockfill materials，the   and   curves can be fitted with power function. Based on the Nanshui elastoplastic model with double yield surface(Shenzhujiang model)，an elastoplastic model with double yield surfaces in the p-q plane was established，which is suitable for constant stress ratio path. According to the direction of plastic strain increment，the reasonable shape of yield surface about   under constant stress ratio path is investigated. Finally，taking the Nuozhadu dam main rockfill for case study，the model parameters are determined and the applicability of the model is analyzed primarily.

The paper presents an experimental and theoretical study of the Gaomiaozi bentonite-sand mixture. The result shows that the three-dimensional swelling pressure increases exponentially with the dry density，and decreases exponentially with the sand content. Anisotropy of swelling pressure is observed in the mixture and the vertical swelling pressure is greater than the horizontal swelling pressure. Both the sand content and dry density affect the anisotropy of the sample. When the sand content is at a lower range，the increase of the sand content has a more obvious impact on the anisotropy. When the sand content is above 30%，the increase of the sand content impacts it less. The anisotropy of the mixture becomes more obvious and gradually stabilized as the dry density increases. Using the index of bentonite dry density based on volume fraction，the three- dimensional swelling pressure empirical model of Gaomiaozi bentonite and its sand mixture has been established，which provided a basis for the buffer/backfilling materials design of deep geological repository of high-level radioactive waste.

Morphological characteristics of hysteretic curves consist of closure，degree of width，degree of tilting to strain axis，intensive level and the area of the hysteretic curve. Residual strain ?p，the ratio ? of short axis length to long axis length，the gradient k of the long axis，the distance d between two center points of adjacent hysteretic curves，and the area S of the hysteretic curve are used to quantitatively measure morphological characteristics of hysteretic curves. Triaxial tests for different negative temperatures are carried out to study morphological characteristics of hysteretic curves of Qinghai—Tibet frozen clay. The test results show that：?p，?，k，d and S change little with increasing cycle numbers under the same dynamic load condition；therefore，average values of ?p，?，k，d and S are adopted to measure morphological characteristics of hysteretic curves；?p，?，d and S increase gradually，and k decreases gradually with increasing dynamic strain amplitude. In other words，closure decreases，degree of width increases，intensive level decreases，degree of tilting to strain axis increases and the area of the hysteretic curve increases with increasing dynamic strain amplitude，which indicate that residual plastic strain，viscosity，degree of microscopic damage and energy dissipation increase gradually，and stiffness decreases gradually.