According to the damage problem of the support equipment for mining when the rockburst happens，using the excellent anti-impact and energy absorption characteristics of the foam metal，a kind of device，which can subtract the shock waves and consume the external impact energy rapidly，is developed. The primary study and verification of the device?s expecting function has been researched by the mechanical analysis and laboratory experiment；and an ideal result is got. The experimental result shows that：the device can realize the expected target of 100 kN bearing capacity by the external spring?s control；the device can realize the function of replacing the deformation that the block pin can break through the max static friction and extend outside finally without locking phenomenon happening；absorbing energy material has a good compressive strength and better energy absorption efficiency. The total energy absorption of the device is 1 650 J，which is closed to the theoretical calculation result 1 550 J. The study and design of the device lay a good foundation to further solve the damage problem of the support equipment for mining when the rockburst happens and improve the anti-impact and supporting ability of the support equipment.

Considering the situation of deep roadway of Juye mining area，of which the ground stress is high and the top coal is thick，and guided by the support idea，which is first anti-pressure，second pressure relief，third anti-pressure，high strength pressure relief anchor box beam(PRABB) support system was developed. PRABB support system has the advantage of low prestress loss，quantitative pressure relief，good supporting force transmission effects and a large contact area. Taking mine I-steel beam #12 and box support beam as trimmer beam respectively，two cross anchor beam support systems，two longitudinal single anchor beam support systems and two longitudinal double anchor beams support systems were designed. Taking deep thick top coal roadway of Zhaolou colliery as the engineering background，preliminary analysis of supporting effects of the support systems was produced by numerical test，and all the support systems were field-tested in crossheading of working face 3302. The field test results show that：(1) Six support systems are all better in controlling surrouding rock deformation than original support scheme. (2) Support effects of PRABB support systems are better than those of mine I-steel anchor beam support systems，and the roadway deformation of PRABB support systems is 15%–25% less than that of mine I-steel anchor beam support systems. (3) Among all the support systems，the longitudinal single anchor beam support systems are best in controlling surrounding rock，the longitudinal double anchor beams support systems take second place，the cross anchor beam support systems are relatively poor. Control mechanisms of different arrangement modes of beams are analyzed by test results. By longitudinal single anchor beam support systems，deformation of key position in thick top coal roadway is controlled well；it is helpful in making the best of self-bearing ability of surrounding rock and controlling roof deformation. In the deep thick top coal roadway supporting，longitudinal single anchor box beam support system is better for controlling surrouding rock deformation in a cost-effective way；so that the supporting demand is satisfied.

In order to obtain the precursor information of intense instability destruction of coal and rock mass which is induced by the deep mining，roadway excavation and face mining disturbance，according to the abnormal signal of coal samples would produce under external loads，which include elastic wave，charge，temperature signals，etc.，monitoring devices including acoustic emission instrument，LCR bridge，infrared thermograph and static strain devices are used to synchronously monitor the failure process under uniaxial compression. In order to study the multiparameter evolution characteristics，all data are selected in the same time axis. Meanwhile，principal component analysis and factor analysis in multivariate statistical analysis are used to analyze the original monitoring results of multiparameter；and the results show that acoustic emission and stress monitoring results could better reflect the characteristics of the samples? precursor destruction and get the precursor information of coal samples? instability destruction.

Taking the oval rock circle on the slope of an oval furrow pit for example，combining the axial ratio theory，the circle stress of the stable slope is derived for the oval deep furrow open pit under the conditions that the rock mass is continuous，homogeneous and elastic，and the rock mass is forced by the combination of weight stress and horizontal geostress. According to the determination method for getting the best axial ratio of roadway，the slope safety factor is derived with Mohr-Coulomb criterion. Based on the critical gliding conditions of micro-body in the slope，the critical stable slope angle is calculated. Therefore，the slope shape is determined. Compared with the slope shape determined by the traditional theory，this new shape can make a great reduction on the amount of peeling rock under the precise of guaranteeing the slope stability.

Internal and external pore characteristics of raw coal sample of medium and high degrees of metamorphism which were obtained from Liupanshui mining area were studied by using TESCAN VEGA II scanning electron microscope(SEM)-energy-dispersive X-ray(EDX) and ASAP2020 specific surface microanalyzer. Triaxial seepage experiments of constant different gas pressures were carried out by independently developed traixial seepage device. The results show that：(1) There is positive correlation between metamorphic grade of coal and interior and external pore characteristics. The higher the metamorphic grade is，the higher the fractal dimension is and the greater the raw coal adsorption capacity and pore volume are. (2) There is also positive correlation between internal and external pore characteristics of raw coal and permeability. The more developed the internal and external pore，the greater the permeability is. (3) Under the conditions of constant mean effective stress and temperature，with the increasing gas pressure，at first the permeability sharply decreases and then tends to decrease gradually；and the relationship between permeability and gas pressure obeys exponential distribution. The research results have some theoretical significance to gas disaster prevention and development and utilization of coalbed methane of Liupanshui mining area.

Employing Metravib dynamic mechanical analyzer，saturated rock samples are loaded under sine wave loading model to simulate the viscoelastic behavior when seismic wave propagating in viscoelastic media. The static load is fixed to 120 N，and the dynamic load of the sine wave is 80 N；so that the total loading force is controlled under yield stress. Temperature is controlled between －40 ℃ and 100 ℃，and the frequency range is from 5 Hz to 400 Hz. Such two kinds of saturated rocks as pump-oil saturated Pengshan sandstones with two different porosities are tested under uniaxial cyclic loading. The variations of attenuation，elastic modulus，and elastic wave velocity with temperature or frequency are obtained. The energy attenuation peaks shift to higher temperatures when the frequency increases，which can be considered as thermal relaxation regularities. Damping attenuation mechanism is used to explain the experimental result that amplitude of attenuation peak decreases with the increasing frequency. The experimental results are in accord with the thermal relaxation regularities obtained by low-frequency resonant standing wave experiments，which show that the thermal relaxation regularities may widely exist in saturated rocks. The experimental results indicate that the elastic modulus and velocity increase with the increasing frequency and decrease when temperature increases. There is obvious frequency dispersion，and the dispersion weakens at high temperature area. The studies of ranges of frequency and temperature are very helpful to the study of theoretical model and seismic data interpretation. Study of attenuation of saturated rock is valuable for geophysical exploration，especially the exploration of geothermal steam or gas reservoirs.

Large-scale shaking table test was performed to study dynamic response characters and failure mechanism of rock slopes triggered by Wenchuan earthquake. Sine waves with different frequencies，amplitudes and duration times were mainly input. Testing results show that：acceleration amplification coefficients increased nonlinearly with the increasing elevation，and they almost reach to maximum at slope surface and shoulder. Horizontal acceleration is amplified more obvious than vertical acceleration at top part of slope(above three-quarters of slope height) which is the opposite at the lower part. Acceleration amplification coefficients increased with the increasing seismic frequency nonlinearly；distribution of acceleration in slope body changed with variation of frequency. Once the input frequency approximated to the natural frequency of model slope，dynamic acceleration is amplified most obviously. Acceleration amplification coefficients increased with the increment of seismic wave amplitude；but amplitude doesn?t change the distribution of acceleration in slope body. Duration time of seismic wave has little influence on dynamic characters. Slope structure controls the deformation modes of rock slope；and acceleration amplification coefficients of bedding slope are about 15% more than those of the homogeneous slope，because of a large amount of structural surfaces in bedding slope which can make propagation of seismic wave more complex.

Based on existing research results and incremental dynamic analysis(IDA)，a performance-based seismic stability assessment approach specified for large underground cavern group is proposed. On the basis of this procedure，the selection of ground motions via PEER-NGA database，which provides the optimal input seismic ground motion for IDA，is discussed；and the selections of intensity measure and damage measure specified for large underground cavern group are processed，thereby providing appropriate earthquake intensity index and seismic performance characterization for IDA. The performance objectives are then classified based on the electricity generating duty of the cavern as serviceability and safety. Reference earthquake motions are specified for each objective as operating basis earthquake and safety evaluation earthquake. The underground cavern group of the Dagangshan hydropower project is taken as a demonstrating case. The results show that randomness of ground motion is well premeditated in this approach；and aseismic performances of cavern group can be given with this approach. Followed by probabilistic results of seismic vulnerability，this approach can provide criterion on the seismic stability assessment of large underground cavern group.

Comparing with directly arriving waves，multiple-scattering coda waves are highly sensitive to physical properties and stress variation of medium. In this paper，a test system is established and experimental studies of scattering waves on concrete and rock samples are carried out. The coda wave formation mechanism and influence factor are analyzed. The coda wave interferometry(CWI) by cross-correlation of coda waves and the data processing method are also discussed. The formations of scattering wave and coda wave are significantly influenced by the rock scatters concentration and size，ultrasonic polarization direction and frequency. The accuracy and sensitivity of velocity changes by CWI are an order of magnitude higher than P-wave and S-wave velocities. It is crucial to this high precision technology that the repeatability and stability of measurement system，high signal-to-noise ratios of coda waveforms and cross-correlation analysis time window selection. The stress dependence of wave velocities for the concrete samples is attained. The coda wave velocities of all the samples increase with the increasing stress，which is same to directly arriving waves. The sensitivity of coda wave velocity changes decreases with the increasing of Young?s modulus. In this experiment，CWI is also used for monitoring the building pillar?s velocity change with environment humidity and water saturation process in a concrete sample. It is shown that CWI is a high precision monitoring means to monitor the variation of media properties.

Based on in-situ microseismic data，the features of blasting vibration and rock fracture microseismic signals were studied. Firstly，using the wavelet packet analysis method，the microseismic signals were decomposed into 5 multi-scale，32 frequency bands to calculate the signals energy under different bands. Secondly，via building 4 new frequency bands to compare the rock fracture signals and blasting vibration signals，the energy distribution was different，and the contrasting characteristics was more obvious. The results indicate that the frequency band energy distribution character of microseismic signals in mine field are as follows：the energy of rock fracture signals was concentrated in S5，0–S5，7 bands(0–125 Hz)；blasting vibration signal was more obviously concentrated in S5，24–S5，31 bands(375–500 Hz). This analysis procedure provides a new method for recognizing blasting vibration and rock fracture signals，and the calculated distribution feature of signals energy can be used to recognize microseismic waveforms as feature index.

For knowing the variation characteristic of rock microstructure under freezing and thawing cycles，the experimental study on granite sample is conducted under different freezing and thawing cycles of 0 time，10，20，30 and 40 times with the freezing temperature of －40 ℃ and thawing temperature of 20 ℃. The nuclear magnetic resonance(NMR) is used to test the samples after freezing and thawing cycles；and the crosswise relaxation time T2 distribution and NMR imaging are obtained. The results show that：T2 distribution of granite exhibits three peaks and the subtotal spectrum area between the first peak and second peak occupies more than 98% of the total area，which means the micro pores are in the majority. After different freezing-thawing cycles of 10，20，30 and 40 times，the T2 spectrum area has changed obviously；and the porosity has increased by 14%，0.9%，16.2% and 1.6% respectively. Also，the space distributions of pores have been visually shown by the NMR imaging. The variation law of NMR characteristics in rock under freezing-thawing cycles has provided the reliable experimental results for the research works of rock damage mechanism under freezing and thawing cycles.

In-situ experimental investigations on thermal-mechanical coupled effects on physical and mechanical behavior of Beishan granites have been carried out through high temperature scanning electron microscope(SEM) testing system. Studies have clearly indicated that both mineral composition and mineral particle size are quite different for Beishan granite；and they have different thermal and mechanical properties(or hardness)，which greatly affect the failure mechanism and fracture toughness of granite. Thermal cracking，the initiation，propagation and coalescence of microcracks are greatly affected by thermal-mechanical coupled mechanism. In addition，these mechanisms will in turn affect other mechanisms，such as variations of seepage and chemical fields. For model I crack sample of Beishan granite，the crack propagation direction is proximately perpendicular to the direction of tensile stress. In addition，the initial defects and larger mineral particles have also greatly affected the granite fracture path. Especially with the temperature changing，granite fracture mechanism will change from the boundary(intergranular) fracture mechanism at low temperature to the coupled mechanism of boundary(intergranular) and grain(transgranular) fracture. Experimental data also show that the average fracture toughness of Beishan granite before 75 ℃ is about 4.728 MPa•mm1/2，while approximately 3.048 MPa•mm1/2 after 75℃，which deceases about 35%. The main reasons are due to the increasing thermal cracking with the increasing temperature and loads，which lead directly to the increasing microcrack and the decreasing cementation of mineral particles. All of these gradually affect the fracture toughness of granite. In addition，they will affect the seepage and chemical fields. Therefore，the thermal-mechanical coupling effects should not be ignored in nuclear waste repository design.

In order to solve the freezing damage problem of tunnel in cold region，an innovative heating system—tunnel heating system using heat pump was introduced for the first time to Linchang tunnel in Inner Mongolia Autonomous Region of China. Tunnel heating system consists of heating section，absorbing section，heat pump，collector and distributor line. The heating section is at the portal of tunnel and heated by the heating pipes located between secondary lining and insulation layer. The heat conduction of heating section is transformed to the heat conduction of composite medium in the cylindrical coordinate system. Its analytical solution was obtained using the finite integral transfer method. The yearly heating load is calculated by using the analytical solution under steady periodic conditions at different insulation layer thicknesses. These loads are used as inputs to an economic model including the cost of insulation material and the present value of energy consumption cost lifetime of 30 years of tunnel to determine the optimum insulation layer thickness. The investigation is carried out for Linchang tunnel in Inner Mongolia Autonomous Region of China. Results show that the energy costs decrease with the increasing insulation layer thickness；the cost of insulation material increases linearly with the increasing insulation layer thickness. Total cost，which is sum of insulation material cost and energy cost，decreases with the increasing insulation layer thickness. The optimum insulation layer thickness is obtained to be 8 cm；the yearly heating load is 580 MJ/m2.

Taking PGP-X well located in Northeast Sichuan province as the research object，the rocks have been sampled respectively between depths of 2 140–4 914 m. Laboratory experiments of static and dynamic mechanical properties of the sampled rocks are performed with the split Hopkinson pressure bar(SHPB)and material test system. By using LS-DYNA，piston-drilling bit-rock interaction system model for air hammer bit drilling is established. In the simulation model，H-J-C dynamic constitutive model is adopted for rock. Taking the damage accumulation caused by the repeated impulsive load into consideration，rock intensity at well bottom is modified after being impacted every time. On this foundation，drilling parameters，structure parameters of air hammer，and the relationship between impact energy and crushing work ratio are researched；and the influences of impact energy，final impacting speed，drilling pressure，impact frequency，rotary speed，well depth and lithologic characters on rock crushing efficiency are explored. The analysis results show that the impact energy-crushing work ratio curve has fluctuation zones and stable zones with clear boundary，so that the critical impact energy and critical drilling pressure of air hammer bit drilling can be obtained. Further research indicates that the critical impact energy and critical drilling pressure are closely related with well depth and lithologic character. With the increase of well depth and rock hardness，both critical impact energy and critical drilling pressure have a tendency of gradually declining. After the simulation of air hammer bit drilling in different formations and lithologies，combinations of critical impact energy，critical drilling pressure，the best rotary speed and impact frequency in typical deep formations are recommended. These results can be for references in field practices for air hammer bit drilling.

Based on geological survey，influence of confined water on stability of translational landslide is discussed. Combining with geological environmental condition of Xiashan landslide，the typical groundwater seepage model of translational landslide is established；and the result of slope stability calculation becomes more reasonable considering action range of confined water. Based on one-dimensional steady seepage theory，calculation formula of action range caused by confined water is deduced；and then parameter sensitivity of this formula is analyzed. The calculation results show that action range of confined water follows established law within a certain range of each parameter：(1) Action range of confined water decreases linearly with the increase of permeability coefficient. (2) Action range of confined water increases linearly with seepage discharge. (3) Action range of confined water takes on parabola shape with thickness of permeable layer，and it is accelerated decreasing trend with the increase of permeable layer thickness. Calculation results also show that the stability coefficients of landslide decreases linearly with the increase of action range of confined water.

The uniaxial compression cyclic loading and unloading tests on fine sandstone comes from the foundation rock of a nuclear power station are carried out on the MTS 815 Flex Test GT rock mechanics test system. The longitudinal and transverse deformation characteristics of fine sandstone are studied under cyclic loading；and the effects of cyclic loading numbers and dynamic stress amplitudes on dynamic elastic modulus，dynamic Poisson?s ratios，damping ratios and damping coefficients are discussed. The results indicate that the longitudinal strain is larger than the transverse strain for the same stress. With the cyclic numbers increasing，the increment of longitudinal strain is larger than that of transverse strain under low amplitude stress；but it is reverse under high amplitude stress. The changing characteristics of stress-strain curves for the unloading process of transverse strain hysteresis loops and the loading and unloading processes of longitudinal strain hysteresis loops are all outstanding down，while the changing characteristics of loading process for transverse strain hysteretic loops are reverse. With the dynamic stress amplitude increasing，dynamic elastic modulus and dynamic Poisson?s ratio increase on a parabola and linearly，respectively，while the damping ratios and damping coefficients decrease by power function law. The damping parameters gained by the sixteenth hysteresis loops can completely denote the damping characteristic of the testing rock. With the cyclic numbers increasing，damping ratio and damping coefficient both increase linearly；and the increment under low amplitude stress is larger than that under high amplitude stress.

Triaxial unloading creep tests with alternatively distributed soft and hard rock specimen from auxiliary traffic tunnel of Jinping II hydropower station are carried out by the rock servo-controlled rheological testing machine. The creep laws of axial and lateral deformations under unloading confining pressure are obtained. According to creep test results，axial and lateral deformations are both unchangeable under high confining pressure with time；and the creep phenomenon of rock specimen is not obvious. As confining pressure decreases gradually，the specimen creep deformations become more and more prominent，and the typical creep three stages of rock appear；and the specimen creep deformations increase nonlinearly until the specimen damages. The creep rupture form of rock specimen is mainly shear failure and with a certain degree of tension damage；and the angle between failure plane and level is 45°roughly. Shear rapture surface is relatively single and smooth；and the evolution process of failure surface is along green schist bedding with lower strength and parallel to bedding plane. Before the accelerated creep stage，lateral creep deformation of rock specimen is smaller than axial creep deformation，while in the accelerated creep stage，lateral creep deformation and creep rate are both higher than those of axial creep，which suggest that the lateral creep deformation is more sensitive than axial creep deformation，and the specimen volume dilatation effect is remarkable with time and the decreasing confining pressure. In the condition of unloading，when the applied load is less than the long-term strength of rock specimen，the rock unloading creep parameters are related with unloading quantity，they are gradually weakening with the increase of unloading quantity；but when the applied load exceeds the long-term strength of rock specimen，the rock unloading creep parameters are related with both unloading quantity and creep time.

According to electron microscopy scanning experiments，it is found that slate has significant blasto-stratification structures and plate cleavages structure. As a result，mechanical characteristics of slate can be revealed by Brazilian disc splitting tests. Based on the disc splitting tests under seven different kinds of bedding angles θ，three kinds of failure forms of disc can be obtained as follows：pure tensile failure when the bedding angle ?＜45°，shearing failure when the bedding angle ?＞75°，and both tensile and shearing failure when the bedding angle ? is between 45° and 75°. Meanwhile，Because of the impact of internal bedding structure on the slate，tensile strength of the slate gradually decreases with the bedding angle θ varying from 0° to 90°. Moreover，the bedding angle has a slight influence on the elastic modulus and Poisson?s ratio perpendicular to the isotropic plane；and the elastic modulus perpendicular to the isotropic plane is slightly smaller than that of the isotropic plane.

Because the Brazilian disc tensile strength formula is the analytic solution based on elastic mechanics plane problems，the results calculated by this formula are very different with the direct tension test results. Based on this，splitting tensile test on more than 100 sandstone disc specimens with different thickness-to-diameter ratios are conducted. The test results show that the tensile strength increases gradually with the decreasing thickness- to-diameter ratio；when the thickness-to-diameter ratio is less than 0.3，the tensile strength gradually increases and tends to a relatively stable value；and the change curve can be better simulated with cubic function. In order to fully grasp the effect of thickness-to-diameter ratio on tensile strength，3D finite element models with different thickness-to-diameter ratios are established especially；and the distribution law of equivalent stress on disc central axis is studied in detail. The study results show that the maximum tensile stress on central axis appears in the center of the specimen end face；and the larger the specimen thickness-to-diameter ratio is，the greater the tensile stress in the center of disc end face is. The first fracture starting point is in the center of end face not in the internal center point；and the 3D finite element calculation results can provide a favorable evidence for the distribution law of tensile strength accurately. According to the multivariate linear regression of the 3D finite element calculation results，a modified formula of the Brazilian disc splitting strength considering the thickness-to- diameter ratio is given；and the modified formula has better applicability. The research results provide favorable evidence for testing tensile strength of rock accurately.

The superficial saturated silty soil of the Yellow River submerged delta represents space heterogeneity，which leads to some geological disasters happening. To reveal the formation mechanism of heterogeneity，flume experiment is used to simulate the process of waves to the silty soil seabed. The soil strength，pore pressure and particle size changes are real-time monitored. Monitoring results show that the soil nonuniform changes are directly related to the strong wave later reconstructions. After the liquefaction of surface soil under the action of waves，fine particle material upward migration causes sediment vertical nonuniform of sediment. In a certain depth，also strength and particle size nonuniform body appears at the same time. For further analysis of the causes of formation，wave cyclic loading is in-situ simulated in the tidal flat of delta and the electrical resistivity testing technology is used for monitoring the state changes of soils. The research shows that in a certain depth，for fine grains of material，lateral migration occurs under the cyclic load，which causes uneven distribution of material. Vertical and lateral migrations contribute together to the nonuniform transformation of superficial sediments. Sharp increase of excess pore water pressure caused by wave is the major impetus of material migration；and the lateral displacement of soil grain induced by wave shearing action promotes the migration. In the process of wave action，it is also found that there is a stable layer under the violent area of silty soil all along.

Slurry shield with outer diameter of 11.58 m was used in Shanghai West Xianxia road tunnel which was undercrossing the taxiway of Hongqiao airport. Through the risk analysis of shield crossing construction，the corresponding control measures were given. Before advancing of the shield machine，the control rules of construction parameters of tunnel shield were studied through field driving test，which provided the guidance for construction parameters settings during shield advancing；finally，the settlement value met the control standard requirement of airport taxiway. In order to solve the limitation in terms of monitoring space and frequency on ground settlement in flight forbidden zone，the horizontal inclinometer monitoring method is applied by using trenchless technology，through which monitors could know the accurate disturbance of soil above the shield in time. The monitoring data show that horizontal inclinometer monitoring by trenchless method can indicate the deformation rules of soil layers when the shield is undercrossing the airport without flights stopping. This kind of monitoring method avoids the disturbance to the airport operation，which is significant to the similar projects.

To identify groundwater recharge and migration rules and guide the grouting treatment design and construction of water gushing underground engineering，tracer experiment for the hydraulic characteristics research of large area is introduced into the gushing-water underground engineering control. Base on the ultraviolet spectroscopy scanning method of low concentrations of colored tracer and data analysis technology，acquisition method of hydrological information(hydraulic connection time，the correlation coefficient of recharge，fracture space volume，groundwater flow rate and pressure) is proposed. According to the analysis of the tracer experiment result，choice of grouting material and determination of the grouting parameters can be put forward. Taking an iron ore for example，tracer experiment(application methods，data processing and application results) in gushing-water engineering control is described detailly，which is supposed as a reference to similar engineering.

Taking the Baihua Bridge rock slope which is seated in Yingxiu Town as case study，three-dimensional discontinuity network simulation method is used to calculate the rock quality designation(RQD). On the basis of accessing discontinuity simulation parameters by statistics of discontinuity measurement data，three-dimensional discontinuity network picture is got by Monte Carlo method. Fifty four survey lines on behalf of drill are fixed up in all directions of main sliding planes，main sliding cross-sections and main sliding horizontal planes. Every RQD value of drilling is obtained by statistics of percentage ratio of sum of core length more than 10 cm of each drill core to total drilling，and then the final RQD value is defined as the expected value of these 54 RQD values. At the same time，volume RQD method is also used to calculate RQD. The relative error can be got by comparing the results from the two methods and the equivalent drilling RQD which is gained by measuring discontinuity surface. The relative error of volume RQD method is 24.6%，simultaneously relative error of three-dimensional discontinuity network simulation method decreases to 3.3%. It is proved that the three-dimensional discontinuity network simulation method has a low relative error and a high accuracy. Consequently，it is a good method to calculate RQD，and has a broad prospects in practical application.

Based on the basic variation characteristics of void ratio and water content with net stress and matric suction，the relationships of void ratio and water content with net stress and matric suction are established. Combined with constitutive relation of unsaturated soil，elastic moduli   and  ，and volumetric moduli  and   in the form of net stress and matric suction，as well as water content are obtained. Then void ratio-net stress-matric suction 3D surface and volumetric water content-net stress-matric suction 3D surface are fitted with experiment data；and the parameters in the relationships of elastic moduli   and  ，and volumetric moduli   and   with net stress and water content are obtained. The influences of net stress and water content on the four moduli are analyzed. The analysis results are as follows：Under a certain net stress，modulus E decreases with the increase of mass water content；the larger the net stress，the more significant the decrease of modulus E with the increase of mass water content；under a certain mass water content，the larger the net stress，the larger the modulus E. Modulus H decreases monotonously with the increase of mass water content and increases monotonously with the increase of net stress. With the increase of net stress，volumetric water content increases at low mass water content and decreases after the mass water content increases to a certain degree. Under a certain net stress，volumetric water content decreases with the increase of suction；under a certain mass water content，the influence of suction on volumetric water content is weakened by increasing net stress.

In order to study the deformation of destructured loess induced by structural damage under coupling of stress and moisture，the macromechanics reflection of structured loess is analyzed，which is induced by structural damage development，by analyzing the deformation of structured loess under compression tests and triaxial tests. The analysis result shows that water content increasing，consolidation pressures increasing，and shearing would cause structural damage of loess. With the water content increasing，structural damage of loess is more prominent by compression and shearing. When consolidation pressures are much larger，structural damage of intact loess by compression and shearing is significant，and the secondary structure and shearing-compression are increasing. Based on structural parameter proposed by comparing with the stress ratios of intact loess and saturated remolded loess during triaxial experiments，and utilizing the stress ratio damage equation and strain damage equation，the structural damage evolution equation is proposed by regarding structural damage loess as complex materials composed of intact loess and destructured loess. Based on the intact loess following Hooke?s law and normal consolidation loess following modified Cambridge model，the elastoplastic damage constitutive equation is proposed by regarding deformation of destructured loess as elastic deformation of intact loess and elastoplastic deformation of normal consolidation loess. Meanwhile，the rationality of constitutive relationship is tested and verified by comparing and analyzing test curves under different moistures and theoretical curves described by the elastoplastic constitutive model proposed in this paper.

The behavior of soil-structure interface is crucial to the design of pile foundation. The radial unloading occurs during the process of hole boring and concrete curing，which will effect the load transfer rule of pile-soil interface. Through the large shear tests on interface between clay and concrete，it can be concluded that the normal stress history influences significantly the shear behavior and strength parameter of interface. The numerical simulation of bored shaft-soil interaction problem requires proper modeling of the interface. Through taking the energy on the interface as a hardening parameter and viewing the shearing process of interface as the process of the accumulated energy dissipated to do work，considering the influence of normal stress history on the shearing rigidity，a mechanical model of interface between clay and concrete is put forward to take the effect of normal stress history into consideration. Then，The determination methods for the model parameters are introduced. The model based on a legible mathematical theory and all its parameters have definite physical meaning. The model is validated through the data from direct shear test. The results show that the model can reproduce and predict the mechanical behavior of interface between clay and concrete under arbitrary normal stress histories.

In order to evaluate the liquefaction of sandy soil in a depth range from surface to 43 m for the undersea tunnel project of the Hongkong—Zhuhai—Macao Great Bridge in detail，the method which combines the experiment data from the dynamic triaxial liquefaction test and the equivalent uniform cyclic shear stress deduced from the analysis method of equivalent linearized seismic response of soil layers，is used to give a primary evaluation. Then，the dynamic response method for potential liquefaction analysis is used to further evaluate and classify the liquefaction in detail. The result shows that liquefaction is still possible for the sandy soil with the depth more than 20 m. Considering that there is no specific code yet in Chinese Mainland for the evaluation of liquefaction of sandy soil with the depth more than 20 m，the strategy and method in this paper which are used to evaluate the sandy soil liquefaction in deep layer will be useful for references.