It is widely accepted that the field or in-situ strength of massive rocks is approximately (0.4?0.1)?c，where ?c is the uniaxial compressive strength obtained from unconfined laboratory tests. In addition，it has been suggested that the in-situ rock spalling strength，i.e. the strength of the wall of an excavation when spalling initiates，can be set to the crack initiation stress determined from laboratory test or field microseismic monitoring. These findings were based on either Kirsch?s solution or simplified numerical stress modeling(with smooth tunnel wall boundary) to approximate the maximum tangential stress ?max at the excavation boundary. In this article，it is suggested that these approaches ignore one of the most important factors，the irregularity of the excavation boundary. It is demonstrated that the“actual”in-situ spalling strength of massive rocks is not equal to (0.4?0.1)?c，but can be as high as (0.8?0.05)?c when surface irregularities are considered. It is demonstrated using the Mine-by tunnel notch breakout example that when the realistic“as-built”excavation boundary condition is honored，the “actual”in-situ rock mass strength，given by 0.8 ?c，can be applied to simulate progressive brittle rock failure process satisfactorily. We conclude that the interpreted，reduced in-situ rock mass strength of (0.4?0.1)?c without considering geometry irregularity is therefore only an“apparent”rock mass strength.

In order to describe the damage evolution state of sandstone during the uniaxial compression comprehensively and objectively，a joint test method combining electrical resistivity and acoustic emission(AE) has been proposed. And the electrical resistivity and AE response characteristic of 30 sandstone samples during the whole process of uniaxial compression have been studied. The results show that there are strong regularity and complementarity between electrical resistivity and AE information. In the stages of compaction，elastic deformation and plastic deformation，the electrical resistivity is more sensitive to the fissure initiation and development activities；while the AE signal is relatively weak. At the moment of rock samples fracture，electrical resistivity and AE information increase suddenly and the AE information has better synchronicity and sensitivity. Then，after the rock samples fracture，electrical resistivity information still has some changes and tends towards stability；while the AE information restores to a low level. At the same time，the analytic expressions of damage variable based on electrical resistivity have been derived. According to the complementarity between electrical resistivity and AE damage variables，a comprehensive damage variable has been defined；and the damage evolution equations of typical rock samples are obtained. In addition，the precursor characteristic of rock fracture and a status qualitative criterion for rock damage and failure have been proposed. Through comparing the between theoretical stress-strain curve with experimental one during the whole process of uniaxial compression，it is shown that the comprehensive damage variable can reflect and describe the rock samples damage evolution comprehensively and objectively.

According to the raw coal samples from B10 seam of －780 m elevation in Huainan coal mine，the MTS815.04 electro-hydraulic servo testing system is used to carry out the conventional triaxial compression test under high stress. The deformation，strength，parameters and failure characteristics of coal are studied. The results show that：(1) The deviatoric stress-axial strain curves of coal are mainly composed of stages of elastic，yield，post-peak brittle failure or strain softening segment. Among them，the elastic period is longer obviously，and the greater the confining pressure is，the steeper the curve is，the greater the elastic modulus is. But，the yield period is shorter. (2) The post peak brittle failure feature of coal is apparent under uniaxial loading or low confining pressure. As the confining pressure increases，the ductile features start to appear after peak. The higher the confining pressure is，the more obvious characteristics of ductility are. When the confining pressure reaches to 50 MPa，the post-peak axial strain almost presents plastic flow pattern. (3) With the increase of confining pressure，the peak axial strain increases in parabolic trend，and the peak lateral strain increases in linear trend. (4) The deviatoric stress-volume strain curve of coal shows dilatancy mechanism under low confining pressure. The lower confining pressure is，the more obvious the dilatancy features shows. In the high confining pressure，the curve from pre-peak to post-peak is always right extend，and presents a continuous shrinkage state. And with the increase of confining pressure，the peak volume strain presents a parabolic increase form，which reflects the shrinkage characteristics significantly. (5) With the increase of confining pressure，the strength of coal increases in linear trend. The strength parameters c，? are 12.72 MPa，24.12°， respectively. (6) The failure modes of coal samples are mainly given priority to shear failure，and the rupture angle is in the range of 23°–35°. With the increase of confining pressure，the rupture angle increases in parabolic trend. The change can be better explained by Mohr strength theory.

The effect of slope topography on the stability is studied by statistical analysis，experimental tests and theoretical calculation. Firstly，a preliminary result that the stability of concave slope is better than that of convex slope is obtained based on the statistical analysis of 300 sets of failure slope data. Then，the ultimate stable angles of concave slope，convex slope and horizontal slope are researched by tilting the model box test. The results indicate that the ultimate stable angle of concave slope is higher than that of horizontal slope，and the convex slope′s ultimate stable angle is lower than the horizontal slope′s one. Thereafter，the force differences among convex slope，concave slope and horizontal slope are analyzed theoretically；and the phenomenon that the concave slope is more stable than the convex slope is explained. Finally，the safety factors of circular concave and convex slopes are derived employing rigorous limit equilibrium method. The influence factors and changing rules of slope topography effect are also analyzed. The safety factor curves of circular slopes with different curvatures are designed to facilitate engineering applications. Then，the ranges of considering slope topography effect are also suggested. The results provide some scientific references to accurately evaluate slope stability of diverse topography.

For the problem of flow and heat transfer in fractured rocks，two hypotheses of heat exchange between rock matrix and fluid in the fracture are compared analytically. It is found that the same result will be obtained for that the fracture aperture is small in general. A discrete fracture network model is realized in commercial finite element software COMSOL for the computation of flow and heat transfer in fractured rock. Both fluid flow and heat transfer in rock matrix and fracture can be calculated in this model，as well as fluid and heat exchange between them. The results are validated by comparing with analytical solutions. Finally，the model is used to simulate a randomly generated fracture network to study the characteristics of flow and heat transfer in fractured rock；and reasonable results are obtained.

In order to study the hydraulic fracture and crack shape，the large real triaxial simulation experimental system，servo control system of hydraulic fracturing equipment，Disp acoustic emission(AE) three-dimensional orientation technique and CT scanning technique are applied；and the hydraulic fracturing physical simulation testing method and the characterization methods of hydraulic fracture have been established. According to the test，some conclusions are drawn as follows. (1) Using 8 transducers acoustic emission(AE) sources orientation technique，starting-crack pressure and the direction of hydraulic fracture can be monitored continuously. (2) Adding a red tracer into fracturing fluid and parting the sample can describe the spatial morphology of the hydraulic fracturing. (3) When the hydraulically created fracture extended is not along the natural bedding plane，it can easy to form the network crack. The physical simulation and characterization methods of hydraulic fracturing can be used for optimization design，so as to provide technical service for shale gas exploiting.

In order to solve difficult support problems of the large-span coal roadway under the second or multiple mining influence，an example of the working face 20108 ventilation roadway in Gaojialiang Coal Mine is presented. Through analyzing the engineering geological conditions and engineering rocks body characteristics，it is known that the roadway 20108 is the stress dilatancy expansion type composite geological soft rock. The damage mechanisms of roadway are the composite deformation mechanisms IABCIIBDIIIDA；and then the bolt-mesh-cable-grout with steel band coupling support design is put forward. By using the large finite difference program FLAC3D，numerical analysis of coupling support design is conducted. The numerical results show that comparing with non-coupling support，the plastic failure zone is obviously reduced and floor deformation is larger than roof deformation of coal roadway. The deformation of roof；and the floor and two working slopes are effectively in control. The field monitoring deformation of roadway surrounding rock shows that，deformation rates of roadway two working slopes under multiple mining influence are larger than those of the roof and floor，which indicates that deformations of two working slopes control the utilization function of ventilation roadway 20108. The results reveal that support effect of bolt-mesh-cable-grout with steel band coupling support is very good in large-span roadway under mining dynamic loads. Based on the theory of numerical calculation，the application of coupling support to large-span coal roadway under multiple mining influence is feasible；and the field monitoring result also verifies the validity and reliability of coupling support proposed.

Triaxial compression tests and acoustic emission(AE) monitoring were carried out for Jiangxi red sandstone using servo-controlled rock mechanical test system；its permeability was tested with gas at the same time. The rock permeability rules and AE characteristics under the failure processes of three types of stress paths，i.e. conventional triaxial compression，unloading confining pressure at the pre-peak and post-peak strength，were studied. The experimental results indicate that：(1) The peak strength of rock samples increases gradually with the increase of effective confining pressure，which means that the peak strength is sensitive to effective confining pressure. (2) In conventional triaxial compression test，the permeability curves fall slightly before yield and then increase dramatically after yield and suffer a slight pullback at the post-peak strain softening stage. The permeability trends before unloading of confining pressure at the pre-peak and post-peak strength are basically the same as that under conventional triaxial compression process. The curves both grow more rapidly after unloading. (3) Under the same loading path，changes of confining pressure only affect the relative values of permeability during all stages，but not affect the trends of the curves. (4) In conventional triaxial compression test，AE activity is relatively quiet prior to yield，and begins to liven up after yield then tends to be quiet again at the post-peak strain softening stage. Shortly after unloading of confining pressure at the pre-peak strength，AE activity appears extremely active and dense. The strength of signal is relative higher and reaches an obvious peak value. The AE law in the test process of unloading confining pressure at the post-peak strength is similar to that in the process of conventional triaxial compression test. (5) With the increase of confining pressure，rock appears more ductility and less brittleness in failure process. At the same confining pressure，rock presents most brittleness and reaches highest broken degree. (6) The dilatancy points of rock samples are close to the minimums of permeability. There is a well corresponding between volumetric strain and permeability with axial strain. The intensive stages of AE activity emerge after dilatancy. It is shown that there are some links among permeability，AE，stress and (volumetric) strain.

Based on three kinds of existing numerical models，a new analysis model with lining-segment joint-contact surface replaced by beam-spring-compression bar and spring combined element for shield tunnel with double-layer lining is improved. The problems of radial tension existing on the contact surface between strata and segment and between segment and secondary lining，and shear stress independent on shear displacement in contact surface between segment and secondary lining are solved by application of compression bar element，method of point displacement coupling，etc.. The formulas of some critical parameters are given. The influences of contact surface elements number on results are discussed. The mechanical behaviors of Qiantang River tunnel on a high speed railway from Hangzhou to Changsha are studied. The results show that：(1) The bending moment of double-layer lining increases obviously as its thickness increases，and the increasing trend of bending moment keeps basically consistent with that of double-layer lining thickness. (2) The increase of double-layer lining?s thickness has little effect on axial force of double-layer lining. (3) There is no linear relationship between distribution proportions of bending moment on segment and secondary linings and their thickness proportions. The research results have some reference value for the design and analysis of underwater double-layer lining shield tunnel in the future.

Separated two-track tunnels of Beijing Metro Line No.4 Xuanwumen station vertically cross beneath Line No.2 Xuanwumen station. Analyzing the measured displacement of the existing station structure both from the global deformation and the single structural block displacement，we obtain the deformation law of the overlying existing structure during excavation by steps. Research shows that：(1) The existing underground structure′s integral settlement complies with Peck formula，but the displacement of single block between two movement joints is rotation mainly and presents rigid body rotation. (2) The ground loss ratio fitted by Peck formula is 0.118%–0.187%. It is unrelated to the existence of the underground structure and the size of excavation section，but it is associated with the new tunnels′ supporting time and supporting stiffness. (3) The settlement trough width coefficient fitted by Peck formula is 2.44–3.87，which is the 1.05–1.62 times than the coefficient of natural stratum. It is unrelated to supporting stiffness，but it is associated with the reinforcement method，the existence of underground structure and the size of excavation section. The research result can provide reference for the similar engineering.

Acoustic emission tests under triaxial compression of limestone were carried out by MTS815 servo-controlled rock mechanical test system and AE21C acoustic emission monitor. The characteristics of limestone damage evolution under triaxial compression are analyzed through acoustic emission parameters. The results show that：(1) Under the same experimental condition，the maximum acoustic emission ringing counts and energy with the detector inside the confining chamber are more 27.0% and 32% higher than that outside the confining chamber，respectively. The more comprehensive and real acoustic emission signals can be received with the detector inside the confining chamber. (2) The confining pressure can make the acoustic emission activities decrease in the stage of compaction. The time of acoustic emission ringing counts reaching its highest value lags behind the time of the macroscopic failure of the specimen，which indicates that the confining pressure not only improves the shear strength of rock，but also its bearing capacity after the peak stress. (3) The rock damage evolution model is established with the acoustic emission ringing counts under triaxial compression. The damage evolution process of rock can be divided into following four stages：initial damage stage，stable damage evolution and development stage，damage speeding development stage and damage failure stage. The acoustic emission activities are less in the initial damage stage. In the stable damage evolution and development stage，the acoustic emission activities begin to be active with the increase of the acoustic emission ringing counts and energy. In the damage speeding development stage， the acoustic emission activities become extremely active；and the acoustic emission ringing counts and energy reach their peak values short after the macroscopic failure. In the damage failure stage，the rock still has bearing capacity and some acoustic emission events are still active.

The uniaxial compression tests for Himalayas salt rock under different temperatures(20 ℃–700 ℃) and after high temperatures(after 100 ℃ and 200 ℃) were conducted to study mechanical characteristics and failure models. The variations of peak stress，peak strain and elastic modulus were analyzed，and especially focusing on the characteristics of stress-strain curves under high temperature. The research results show that，when the temperature is below 120 ℃，the compression strength and elastic modulus of salt rock decrease with temperature increasing，but increase when the temperature changes from 120 ℃ to 200 ℃. Under higher temperatures such as 500 ℃ or above，the internal structure of salt rock changes and the peak stress greatly reduces. The stress-strain curves of salt rock are quite different in different temperature ranges and 170 ℃ is a threshold temperature. When the temperature is 170 ℃–400 ℃，brittle characteristics no longer appears and salt rock shows significant strain hardening with increasing temperature. The limit temperature that Himalayas salt rock can withstand does not exceed 700 ℃. The carrying capacity of samples after high temperature of 100 ℃ and 200 ℃ is relative lower. Simultaneously，its deformation and elastic modulus are lower. There are more cracks and the integrity is inferior.

A micro-CT experimental system was used to scan a specimen of oil shale subjected to pyrolysis at different temperatures. From 3D CT images based on X-ray attenuation coefficients，the evolution of pores and cracks in the specimen was analyzed at different stages of pyrolysis. The results show that：(1) From 20 ℃ to 600 ℃，the specimen is transformed from a compact state to a porous medium. (2) At the higher temperatures，increasing numbers of voids become interconnected. At 100 ℃，the voids are restricted to a very small region；but as the temperature is raised to 200 ℃，channels for oil and gas seepage are formed within the study region. At 600 ℃，the pyrolysis rate of the specimen is calculated to reach 39.80%；and the largest void is 97.45% of all the voids. All voids are interconnected into one large void，forming a channel for the seepage of oil and gas running through the entire X-rayed region. The study conclusions are of great significance for discovering how the channels for oil and gas seepage developing during in-situ pyrolysis of oil shale.

The direct shear test(DST) is widely used because of its convenience and economy. It is of great significance to improve the reliability of the DST data. Based on the summary of former test results，the DST data correction is divide into two types，single-point area correction method and multipoint area correction method. By simplifying the force analysis model of shearing soil，an area-stress correction(ASC) method is presented. The results show that this method is effective and reliable. The corrected strength parameters are more than those of other two methods. A simple discussion on the practical application of these methods is done. In the derivation process，the area correction coefficient and the normal stress correction coefficient are put forward. The correction coefficients of ASC show that the shear stress on the effective shear plane is greater than the measured results；and the normal stress on the effective shear area is less than the applied vertical stress with the shear displacement increasing. The normal stress on the non-effective shear plane is increasing. Since the disadvantages and defects of the DST，there are some differences between the corrected strength parameters and those of triaxial test. The mathematical analysis and test results indicate that ASC method is effective and reliable. It improves the accuracy of soil shear strength parameters obtained from DST.

Slope dynamic response to an earthquake is a product of interaction between seismic waves of complex frequencies and slope body；different frequency components induce different slope responses. Through shaking table tests，effect of wave frequency on two model slopes is analyzed. The two model slopes are composed of the same materials of high strength，but different structures，isotropic and layered. Firstly，dynamic characteristics of model slopes calculated through excitations of white noises show that，resonance frequency of each model decreases and the internal structure becomes loose as the test is going on；and the first resonance frequency of horizontal component acceleration is larger than that of vertical component acceleration. Then，emphasis is put on the slope acceleration responses and their correlations with changing frequencies. Results show that：(1) Obvious topographic amplification occurs in relative elevation h/H＞1/2 for horizontal component acceleration；while topographic amplification occurs in relative elevation h/H＜3/4 for vertical component acceleration；and the phenomena are independent of the excitation frequency. (2) Under the same excitation intensity，the horizontal component motion produces stronger response as the excitation frequency is increasing，more close to the resonance frequency. The correlation between vertical component response and frequency depends on the structure of model slope. (3) When the excitation intensity increases，the decay of slope structure (i.e. decease of resonance frequency) does not always cause attenuation of response，instead，high frequency excitation still can produce strong response due to the narrowing gap between excitation frequency and resonance frequency. (4) The layered model slope responses more severely than the isotropic model slope. Under strong motion，the structure effect is intensified for horizontal component and weakened for vertical component as excitation frequency increases.

The internal meso-structure development of rock material contributes a lot to its macroscopic mechanical properties. The mechanical properties weakening mechanism and internal meso-structure development of typical glauberite soaked in brine are studied；and the mechanism of mechanical properties weakening is revealed. It is found that under the actions of swelling and disintegration of hydrophilic mineral in the cement of the rock，the dissolution of sulfate，the ion exchange and the chloride ion erosion damage，etc.，the porosity of glauberite soaked in brine is changed nonlinearly with the solution concentration and soaking time. So，the mechanical properties weakens. The strength weakening coefficient decreases to 0.1–0.2 after the glauberite being soaked in brine for 20 d. Because of the water effect and hydration，the argillaceous content contained in the glauberite would swell or disintegrate. So the deformation of glauberite shows the characteristics of strain softening and ductile from the original brittle behavior. The meso-structure development results also show that the pores in glauberite soaked in brine develop more slowly than that in pure water. The pores development rate in fresh water is several to hundreds of times as that in brine. The porosity of glauberite soaked in water for 48h increases to 16.62%，which is 9 times of that of natural state. And the porosity of glauberite soaked in half saturated solution for 48 h is 3 times of its natural state. However，the porosity of glauberite soaked in saturated solution for the same time has an increase of only 2.8%. The change of porosity is mainly due to dissolution and hydration of sulfate in the glaubetire，the water effect and cement of hydrophilic minerals(mainly glimmerton and smectite contents) swelling. These are definite reasons for the mechanical property weakening of the glauberite. The research results are significant either for study of physico-mechanical properties of the glauberite or for in situ leaching mining of salt deposits and salt cavern construction for oil and gas storage and other related engineering practice.

A 2.5D finite element method(FEM) model of train-track-ground is built to analyze the train induced ground vibration with geometric irregular track. Then the expression of train loads is obtained implicitly by simplifying the track as an Euler beam resting on the layered ground. The 2.5D finite element formulas are derived by taking the in-filled trench as heteroplasmon. The screening of in-filled trench on ground under moving train load at high-speed and low-speed is analyzed. Then the parameters of in-filled trench are analyzed in detail. The parameters herein include the width，depth，distance and materials of the in-filled trench. The results show that，the screening as train runs at high-speed is better than that at low-speed train. In addition，increasing the depth and width of the in-filled trench can improve the screening under moving train load；vibration enhancement area appears in a certain range in front of the trench；the isolation effectiveness of nonrigid materials is better than that of concrete in front and back of the trench. The results will contribute to the theoretical and technical development of the screening of ground vibration induced by train load.

High leachate mound is a common problem affecting safe operations in Chinese municipal solid waste(MSW) landfills. The water-retention characteristic，saturated hydraulic conductivity of MSWs and the clogging characteristics of leachate drainage layers are then summarized based on the data measured and from literatures. The influences of initial moisture content，water-retention characteristic and saturated hydraulic conductivities of MSWs and leachate drainage layers on water level of landfill are demonstrated by numerical analysis of moisture transport in landfills. The obtained results show that high leachate mound in the landfills is primarily caused by the decrease of permeability of MSWs with embedment depth and fill age，clogging of leachate collection layers and high initial moisture content of MSWs. Perched water in a landfill occurs in the case that MSWs have low permeability. The numerical analysis result is verified by the monitoring data in a landfill in southern China. The measures to control leachate mound of landfill are presented and put into practice.

More and more deep excavations have been constructed to meet the increasing demands of underground infrastructure. The supporting characteristic of rock-socketed diaphragm is different from that in soil due to the different strengths of the bearing layer. Based on the analysis of field data including diaphragm wall deflections，wall settlements and axial forces of struts，the following main findings are obtained. The diaphragm wall deflections using the intermediary weathered rock as bearing layer are larger than those using clay as bearing layer. The maximum lateral displacements of rock-socketed and non rock-socketed diaphragm walls are 0.20%He and 0.32%He，respectively. The diaphragm wall deflections decrease with increasing system stiffness，which is more obvious for the rock-socketed diaphragm. The settlement behind the diaphragm wall is large when the value of x/He is smaller than 2.0(primary influence zone)，but small while the value of x/He is larger than 2.0(secondary influence zone). The axial forces of the first and fourth struts of rock-socketed diaphragm wall are larger than those using clay as bearing layer. In addition，the total support axial force of rock-socketed diaphragm wall is larger 44.9% than that of clay-socketed diaphragm wall.

Soil displacement around the sliding mass is assumed to be uniformly distributed along the depth of sliding mass and the stabilizing pile is assumed to be elastic foundation beam. Based on the closed-form solution of single-row stabilizing pile under the action of lateral soil displacement around the pile，a theoretical model of double-row stabilizing piles is built by introducing static equilibrium and deformation compatibility conditions of the connecting beam. The shadow effect between double-row stabilizing piles is considered by defining ratio of soil displacement around the rear stabilizing pile to that around the front stabilizing pile. Solving process of the theoretical model is realized by writing programme in Matlab software. A simplified numerical model in FLAC3D platform is established to validate the result from theoretical model. The results show that the internal forces calculated from the numerical model and theoretical model are consistent to each other. The suitable range of the theoretical model is discussed. It is found that the result of the theoretical model is more accurate；and the error of calculating results between the numerical and theoretical models changes larger as the distance between the front and back stabilizing piles increases.

Taking into account the interaction between water flows and electrical currents as well as the pore pressure dissipation under the linear load，one dimensional electro-osmotic consolidation equation under linear load was established based on the extending consolidation process of the general seepage equation to the electro-osmotic field. The analytical solutions of the pole pressure and average degree of consolidation were given under two conditions of the cathode opened and anode closed and two poles opened. The effects of the maximum load and loading rate on the dissipation of pore pressure and the effect of supply voltage on theoretical consolidation degree and experimental consolidation degree were investigated by the method of parametric analysis and test analysis. The pore pressure dissipation curves in single and double drainage under different maximum loads and loading rates，and the curves of theoretical consolidation degree and experimental consolidation degree under different supply voltages were drawn. The results show that the greater maximum load and loading rate are，the faster dissipation speed of pore pressure is. At the same time，the effects of maximum load and loading rate on double drainage is greater than that on unilateral drainage. The greater supply voltage is，the higher the growth rate of theoretical consolidation degree and the experimental consolidation degree are，as well as the variable amplitude of theoretical consolidation degree is weaker than the variable amplitude of experimental consolidation degree in the period of time.

Supposing the track as Euler beam sleeping on a saturated soil，applying double Fourier transform to equilibrium equation of the Euler beam，an implicit load equation is derived. The u-p format 2.5D finite element governing equation is derived by employing Galerkin?s method to dynamic equation of soil in frequency domain and the boundary equation. The corresponding artificial boundary is obtained considering SH waves，SV waves and P waves respectively. The calculation program is conducted by Fortran；and the correctness is verified for the present method from the existing literature. The results show that ground vibration displacement decreases and the acceleration attenuates slowly with the increasing distance. Pore water pressure decreases with the increase of depth；and the first inflection point of pore water pressure curve appears at the interface of 1st and 2nd layered soil. When the depth increase to 10 m，the pore water pressure decrease to 0.

The finite difference scheme of hardening soil constitutive model is derived based on the increment theory of plastic. The finite difference program of hardening soil constitutive model is established so as that the secondary development of hardening soil constitutive model is realized with the platform for secondary development offered by FLAC3D software in VC++ environment. And then，the steps，methods and program essentials of constitutive model?s secondary development based on FLAC3D software are given. The comparison analysis between test results under different stress paths and FLAC3D numerical simulation results with different constitutive model is made so as to verify that the development of hardening soil constitutive model in FLAC3D is correct and necessity. Comparative analysis shows that the FLAC3D numerical simulation results with hardening soil constitutive model accord with test results. The parameters of hardening Soil constitutive model is simple and can be easily determined by conventional triaxial test. Hardening soil constitutive model can not only reflect the nonlinear characteristics of soil，but also can reflect complex stress path of deep foundation pit engineering. So，hardening soil constitutive model is more suitable for computing analysis of deep foundation pit engineering compared with other constitutive model of soil. Implementation of secondary development that hardening soil constitutive model is developed in FLAC3D software expands the scope of FLAC3D application，to some extent，it makes up for disadvantages of FLAC3D in analysis of geotechnical engineering，especially deep foundation pit engineering.