A dynamic triaxial test of tailing slity sand and silt was conducted in order to investigate the dynamic characteristics of Xiaodae tailings and compare the different behaviors of these two tailings. The main experimental conditions consider natural consolidation and mechanical compaction. To make the research results more convincing，the particle size distribution and micro morphology of the tailings were both tested in detail. The results demonstrate that：the clay particles of tailings with less clay mineral cannot enhance dynamic strength. The dynamic shear stress ratio t_d/s_3c under different confining stresses can be normalized well. The increase of dynamic pore water pressure is influenced by vibration time primarily rather than magnitude of dynamic stress. The dynamic internal friction angle j_d decreases with the increase of failure vibration time，and the dynamic effective internal friction angle j_d is ruled by the increase of dynamic pore water pressure. The maximum dynamic elastic modulus E_d0 increases with the increase of confining pressure or consolidation ratio，whereas the maximum damping ratio l_max changes oppositely with these two factors. In contrast to tailing slit sand，tailing silt has the lower dynamic strength and dynamic elastic modulus. The mechanical compaction is more effective for tailing silt，which is beneficial to the dynamic characteristics of both tailings.

Based on the self-developed shear-seepage coupling test device for coal rock，the shear failure experiments of complete sandstone was carried out under normal stress of 2.0 MPa，pore water pressures of 1.0，2.0 and 3.0 MPa respectively. At the same time，the shear fracture surface of different pore water pressures was scanned by the three-dimensional scanner，and it¢s characteristics was analyzed by statistical parameter that was calculated by Matlab software. The results show that：(1) the shear mechanical properties of sandstone will appear“softening” effection under pore water pressure，and the higher pore water pressure is，the lower shear strength of sandstone is， in addition，the deformations of peak shear and the peak normal are smaller. (2) The root mean square of the vertical distance from all points on the shear fracture surface to the base level，the roughness index and the fractal dimension of surface crack decrease with the increase of the pore water pressure，which indicates that the roughness of shear fracture surface decrease with the pore water pressure rising. (3) Through analysis to crack propagation of shear fracture surfaces，it is found that the crack propagation on specimen¢s surfaces can only reflect inner cracks in small range near the surface instead of whole fracture surface in the process of shear test under different pore water pressures.

The seepage characteristic of rock determines the efficiency of oil exploitation and it has important significance for the quantitative evaluation of reservoirs. In order to figure out the influence of the pores，cracks and different mediums in rocks on its seepage performances，spectral imaging experiment was carried out on rock sample by using the microscopic infrared spectral imaging technology. The rock section can be divided into pore and crack regions，transition regions of pore and rock medium，and dolomite medium regions according to the spectral image and absorbance value A. Based on this，a finite element model in which the real structures of the rock sample could be described precisely was established and numerical simulation researching the rock′s micro seepage characteristics was carried out. The results show that：(1) the spectral absorption band of the sample is at 2 500–2 700 cm^－1，showing that the sample medium is mainly dolomite. (2) the greater the dynamic viscosity of the fluid in the two-dimensional flow of the same plane is，the smaller the flow rate of the fluid in the channel is. (3) When the permeability of porous dolomite medium is small，the fluid flow is mainly dominated by the free flow along the crack channels，and the seepage movement in rock medium is weak. With the increasing of the medium permeability，fluid seepage in porous medium is gradually obvious. When the pore throat size is small，the capillary resistance is big，and the fluid does not flow. (4) When the pore throat size is enlarged，the number of preferential flow path increases，the fluid flow range in the rock section increases，and the flow rate becomes large. The results can provide a scientific basis for the development of reservoir reconstruction project，so as to improve the efficiency of oil exploitation.

Based on the principle of strength reduction method combined with FLAC^3D numerical software，two failure criteria ware defined to consider and not consider the tensile failure. And two types of slopes，homogeneous soil slope with different slope angle and slope height，and jointed rock slope with different joint angles，were analyzed to investigate whether the tensile damage should be taken into consideration，and under what conditions the tensile strength must be considered，and the extend of the impact. The results showed that the tensile strength had little influence on the stability of homogeneous soil slopes，but it had greater influence on the jointed rock slopes. When the tensile strength criterion was considered，safety factors of the rock slopes were decreased. And the better of the slope stability，the greater of the impact of tensile damage on the calculation of the safety factor. In addition，for the rock slopes with horizontal or vertical joints，the tensile failure was necessary to be considered in the numerical modelling to obtain satisfactory slip surface and plastic zones. The two different failure criteria were also used to verify sliding failure of a mine slope in the northern part of Italy. And the results verified the previous research conclusion. Finally，different numerical methods，constitutive laws and pore water pressure were discussed in slope failure modelling.

To investigate the influence of macro-crack dip angles on the coal characteristics，acoustic emission(AE) tests under uniaxial compression of coal samples with different dip angles pre-existing crack were carried out by YAW4306 electric mechanical test system and CTA–1 acoustic emission monitor. AE signal characteristics in test process were analyzed，and the effects of macro-crack dip angles on AE response characteristics，peak stress and crack propagation modes were studied. The results show that：the existence of macro-cracks in specimen under uniaxial compression has a significant impact on AE signals，and the response of AE signals is of high consistency with the applied load，so it can well reflect the internal rupture development when macroscopic defects appear under uniaxial compression. The peak stress increase with the dip angles of the cracks，which presents quadratic function relationship by curve fitting. When the dip angle of pre-existing cracks is 0°，15°，30°and 45°respectively，the major crack morphology of coal samples in the failure process is wing crack，accompanied by subtle secondary cracks. While the dip angle rises to 60°and 75°，anti-wing cracks appear on the surface of the coal specimen. There is no obvious propagating crack on the surface when the dip angle reaches to 90°，and the coal samples show a splitting failure mode.

For the deficiency of research and application of the three-dimensional limit equilibrium method，the Hovland improved model and revised Hovland improved model were put forward after modifying the calculating method of vertical force on the element sliding surface in Hovland model and revised Hovland model，whose force analysis is relatively reasonable. Using the GRASS GIS software for the verification of one three-dimensional slope stability analysis，the results shows that when the resolution of grid model is the same the precision of stability factor calculated by improved Hovland models is higher. The slope geologic model construction and stability analysis method based on constraint Delaunay TIN tri-prism elements were presented by introducing Delaunay mesh generation algorithm which can take points，lines，triangle area constraints into consideration. By  adopting the tri-prism slope geologic model，the precision of various calculation models was improved effectively，especially in the case of using Hovland improved calculation models brought up in this paper. Considering the computational efficiency and the balance between calculation accuracy and economy of tri-prism slope geologic model，the research of analyzing the variation of the number of triangles and the stability factor with the minimum triangle area was carried out and the optimal area evaluation index proposed is 1/412–1/206 in Delaunay TIN subdivision. The engineering case study of Heishan open-pit coal mine indicated that the effects of sliding resistance formed in the middle and front of landslide are the main cause leading to high slope safety coefficient in the southern stope.

Using a backfill body disintegration rate tester along with SEM and CT analysis techniques，this paper examines the influence of waste rock incorporation proportion and cement introduction quantity upon the disintegration properties of the treated mass. The disintegration mechanism of the mass is also discussed. The results suggest：at given cement introduction quantity，the backfill body disintegration rate diminishes and its disintegration time shortens with an increasing refuse incorporation proportion. Also at a given waste rock incorporation proportion，the backfill body disintegration rate drops dramatically when the cement introduction quantity is increased. The disintegration process is subdivided into three phases including water absorption disintegration，steady disintegration，and disintegration termination. The treated mass derives it adhesion from the strength of the cement hydration products. The seepage flow is established inside the mass under the seepage pressure and is also the result of the randomly distributed open channels and the constant expansion of closed channels. Channel expansion is driven by attraction of the matrix，and when the backfill body absorbs water the gas-liquid phase transfers incessantly a force to the solid phase：the mass proceeds with disintegration if the force value is greater than the cementation adhesion，the mass does not disintegrate when the force value is less than the adhesion.

In order to investigate the influence of gas pressure on the mechanical properties of sandstone， compression tests of triaxial loading at different confining pressures and different gas pressures were carried out by the self-made“thermo-fluid-solid coupling with triaxial-servo controlled seepage equipment system of coal and rock”. The results show that： gas pressure had a weakening effect on the strength of sandstone. It caused the  triaxial compressive strength and elastic modulus of 3 MPa gas pressure were both smaller than that of non-gas and the strain of rock was larger under the same stress. Because of the effect of gas pressure，the triaxis compressive strength exhibit distinctly nonlinear characteristics. The parabolic Mohr criterion and Hoek-Brown strength criterion were employed to analysis nonlinear strength characteristics. Then based on the results of research，the modified Hoek-Brown strength criteria which considered the effect of gas pressure were proposed. By performance analysis and evaluation，the experimental data is in good agreement with the modified strength criterion. So it can be used to judge the strength of sandstone under the effect of gas pressure.

Considering the deformation of filling material and the interfaces between the rock and the filling materials，combined with the method of characteristics，the three element model(TEM) is employed to analyze wave propagation across filling structure. Comparison with the existing theories，the validity of TEM is verified. Then parametric study is conducted for the effects of the stiffness of the interfaces，the filling thickness，the velocity of the filling material and the frequency of incident waves. Finally，the filling structure with thin filling material is equivalent to joint without filling material and the filling structure with thick filling material is equivalent to the interlayer，two parameters are defined to describe the mechanical behavior of the filling structure. The study results show that the effects of the stiffness of the interfaces，the filling thickness，the velocity of the filling material on wave propagation are divided into two parts by critical values. The effects decrease when the three parameters exceed the critical values. The transmission coefficient is positively correlated with the stiffness of the interface and the velocity of the filling material. The negative exponential function is proposed to describe the relationship between the filling thickness and transmission coefficient. K_ne and E_ne are also closely related to the filling thickness and the stiffness of the contact interface.

Using the coal preparation equipment developed by ourselves，experiments on mechanical characteristics of soft coal were studied under different moisture content and clay content with the help of RMT–150B rock mechanics test system. The results showed that：(1) when the moisture content range from 1.59% to 6.50% in the test，critical moisture content is existed under the same clay content of the soft coal，the compressive strength of coal is the highest and the modulus of elasticity is the maximum at the level of the critical moisture. (2) The compressive strength and elastic modulus of the soft coal content were firstly increased and then decreased and the highest clay content are all about 11.68% under different moisture content when clay content increased from 4.00% to 19.36%. (3) In the same conditions，with the increase of water content and clay content，the brittleness of soft coal decreases while the ductility increases，the poisson ratio also increases. (4) The liquid bridge force of soft coal inter particles with the change of moisture content is the main reason for the evolution of the concept of mechanical behavior，the appropriate amount of clay particles can be used as cement to further strengthen the coal. The research results have important theoretical significance and engineering application value for the safe and efficient mining of soft coal seam.

To study the effect on unloading mechanical properties of sandstone by low pore water pressure，triaxial unloading tests of sandstone under different confining pressure(5，10，15，20 MPa) and pore water pressure (0，0.3，0.6，0.9，1.2 MPa) have been done in TOP INDUSTRIE Multi-function triaxial testing system. It has mainly been discussed about how pore water pressure influenced the sandstone¢s unloading strength and deformation and failure characteristics. The results showed that：(1) With the pore water pressure increasing，the elastic modulus in loading stage gradually decreased. And the decreasing trend of elastic modulus was more obvious under the smaller confining pressure with the same increment of the pore water. (2) During the unloading process，the increasing rate of lateral deformation was obviously higher than that of axial deformation. Moreover，the lateral expansion phenomenon is more obvious under higher pore water pressure and smaller confining pressure，which means the rock specimens are easier to damage. (3) During the unloading process，the deformation modulus of rock specimens decreased rapidly in the beginning and then slowly，and the rock specimens¢ deformation modulus declined dramatically with higher pore water pressure and smaller confining pressure. (4) With the increase of pore water pressure，the confining pressures related to rock specimens failure gradually increased，and the decreasing trend of cohesion and internal friction angle tend to be more obvious，which means the rock pore water pressure accelerates the process of rock failure. (5) The softening and weakening effect of water on the mineral particles and their inter-particle connection，and the water-wedge effect of pore water pressure are the basic reasons for sandstone¢s unloading mechanical properties deterioration. Therefore，concerning to the analysis of unloading deformation stability of wading rock engineering project，the effect of pore water pressure cannot be ignored.

Concrete-rockfill combination dam(CRCD)，a new type of dam，consists of an upstream concrete wall and downstream declivitous rockfill；its dynamic characteristics have not been studied thoroughly so far. Based on this，large shaking table simulation tests of CRCD on the bedrock foundation were carried out to study the impact of the type of water storage，seismic waves，frequencies and amplitudes on the acceleration response. Results show that CRCD model has an obvious amplification effect on the input of seismic waves，and the weak area of the antiseismic is on the top of concrete wall and rockfill which have the maximum peak acceleration. The concrete wall of CRCD is not connected with the dam foundation，which is different from conctrete gravity dam，so the contact surface between wall -rockfill and wall-foundation is the key part of antiseismic design. The rockfill at the dam crest possesses the same obvious "Whiplash Effect" as the conventional earth-rock dams，while the acceleration response of CRCD is less than that of the conventional ones because of the concrete wall’s restriction. Water storage，seismic waves，frequencies and amplitudes have different effects on the acceleration response of the concrete wall and rockfill of CRCD：water storage has a slightly effect on the concrete wall than on the rockfill to weaken acceleration response；the acceleration amplification effect caused by near-field Shifang wave is more apparent than that of cosco-field Taft wave；there is no big difference between the influence of seismic frequencies and amplitudes on the acceleration response of concrete wall and that of rockfill；the acceleration amplification factors gradually decrease with the increase of seismic wave amplitudes and the acceleration amplification factors of the wall top is slightly greater than that of rockfill. The results reveals the acceleration response characteristics preliminarily and provides reference for the aseismic design of CRCD.

To study the time-dependent behavior of rock mass discontinuity，the samples with artificial joint surfaces based on Barton′s ten standard lines were poured using cement mortar. Direct shear test and shear creep test were conducted and the relationship between shear strength and JRC(joint roughness coefficient) was established，the characteristics of creep curves were described and the long-term strength of discontinuities with different values of JRC and normal stress were solved using new method for determining the long-term strength that proposed based on the isocreep-rate curve. The results demonstrate that the creep displacement decreased and the creep failure curves were steeper and steeper with the increasing of JRC. The creep displacement，creep rate and shear stiffness in loading section of muti-stage creep curves increased greatly when the shear stress was higher than stress thresholds. Instantaneous strength and long-term strength have linear relationship with JRC，and the ratio of long-term strength and instantaneous strength decreased with the increasing of JRC，which due to the difference between continuous rock and rock mass discontinuity in time-dependent behavior and the variation of shear area ratio. In addition，the long-term strength determined by inflection point of isocreep-rate curve method meet the range determined by the creep characteristics which can verify the reliability and rationality of the new method.

C-S slurry and GT–1 slurry are two types of quick setting slurry which are frequently-used in dynamic grouting engineering. Considering time-dependent behaviour of viscosity，and using COMSOL Multiphysics as the finite element software，numerical model of crack grouting process in running water was established. The law of slurry diffusion and its influencing factors were studied. Comparing numerical simulation and test results，rationality of numerical simulation is verified. Results show that：Running water restricts the range of slurry diffusion，and significant differences exist between along the flow direction and against the flow direction. Pressure around inflow boundary is gradually approaching the distal groundwater pressure. In initial stages of grouting，velocity in regions near the no flow boundary and outflow boundary is higher than other regions. In later stages of grouting，velocity in different position changes gently. Under the present experimental conditions，initial hydrodynamic flow rate and grouting rate are positive correlated with velocity and pressure in crack. Furthermore，grouting rate shows more effect on pressure in crack than initial hydrodynamic flow rate. Slurry diffusion law of C-S slurry and GT–1 slurry are similar，however，difference of time-dependent behavior of viscosity leads to quantitative differences of diffusion.

Aiming at the Hoek-Brown failure criterion which can be used for an anisotropic rock material，the alterative form for numerical computation is derived，and this form is introduced a 2D FEM code for elasto-plastic analysis of transversely isotropic medium. Taking an assumed rectangular underground cave in a layered rock mass as the computation background，the displacements，the stresses and the plastic zones in the surrounding rock mass are analyzed numerically through changing the dip angle of the bedding surface of rock mass. The results show that the orientation of the bedding surface of rock mass is limited in some angle range，the plastic zones can or cannot occur in the surrounding rock mass，so the anisotropic characteristics of deform and strength of layered rock mass have strong influences on the mechanical state and the stability of surrounding rock mass of a cave. 

In terms of its volume，horizontal salt cavern is appropriate for the thin bedded salt in China，but it would probably intersect with the interlayer. In order to analyze the effects of interlayer on stress and failure of horizontal salt cavern，a model of horizontal salt cavern with interlayer was built. The analytic solutions of stresses of the interlayer and the interface were obtained based on the force balance of the interlayer element and the mechanism of load transfer on the interface. Then the stress formulas and the Mohr-Coulomb criterion were combined together to analyze the interface sliding and the plastic zone of the surrounding rock. It was found that the shear stress on the interface was proportional to the relative displacement of the salt rock and the interlayer. The shear stress on the interface attained its maximum near the salt cavern，and the interface sliding most easily occurred there. The shear stress on the interface increased with the elasticity modulus and the thickness of interlayer. The equilibrium equation of the interlayer indicated that the derivative of the radial stress in the interlayer was related to the shear stress on the interface. The direction of the shear stress changed at the neutral point. Therefore，the radial stress in the interlayer decreased first and then increased. The principle stresses s₁ and s₃ were the tangential stress and the radial stress. The tangential stress of the interlayer was equal to that of the salt rock and the radial stress of the interlayer was less than that of the salt rock. So the plastic zone of the interlayer was wider than that of the salt rock.

In order to determine rock tensile strength in a precise way to minimize the negative impacts of the compliance of the drilling-rod hydraulic fracturing system on the determination of the maximum horizontal principal stress, the multiple-diameter core hydraulic fracturing machine to test tensile strengths of rock cores was developed and manufactured. Based on the hydraulic fracturing process and the thick rock cylinder model in rock mechanics，the test machine includes three major parts：load applying system，pressure monitoring and data acquisition system，specimen holding system. In order to make the test machine and the test method widely accepted and used，57 rock sample tests were conducted with respect to the major influential factors，such as pressurization rate，depth and diameter of central blind hole，ratio of internal to external diameters of hollow rock cylinder. The test results show the depths of internal blind holes do not affect the test results significantly，but can lower the success rate of tests，therefore，it is suggested that the depth of internal blind hole should be 0.7–0.8 times of the total height of rock specimen. The test results also indicate that the diameters of internal holes can affect the test results significantly，and the scale effect does not work effectively when the diameter of internal borehole is greater than 20 mm. Considering the ratio between the internal diameter of internal blind hole and the external diameter of rock specimen，it is suggested to adopt 0.3–0.5 to obtain more stable test results according to the theoretical analysis and test results. The adopted test pressurization rate was about 0.02 MPa/s in this research，which can help get reliable data. The tested tensile strength of slate specimens，extracted in the ordovician-silurian formation of the Paleozoic period，in Changting，Fujian Province，is about 8.4 MPa. These research findings make preliminary bases for standardizing such kind of test method and test machine.

During the construction of tunnel，the excavation process would lead to the groundwater seepage field redistribution and groundwater level drawdown. However，the effect of excavation-induced groundwater level drawdown on tunnel inflow had not been considered in common analytical method. Through the numerical calculation，the change of seepage field after tunnel excavation is analyzed. And based on the numerical solution，the analytical method for calculating the tunnel inflow and lowered water level is proposed by considering the effect of groundwater level drawdown. The results indicate that the pore water pressure around the tunnel and the water level gradually decrease over time during the excavation process. The pore water pressure changes dramatically in the scope of 5 times tunnel diameters and the water table reduces by 26.3% to 56.7%. After the seepage field stabilization，the lowered water level is closely related to the tunnel radius and initial water level，not to the permeability of surrounding rock. Compared with traditional analytical solution and numerical solution，the analytical method proposed can conveniently solve the lowered water level and tunnel inflow for the cases with horizontal and inclined groundwater level.

The study of ground motion amplification effect is basis of the slope seismic design. An inversion method of seismic load is proposed based on white noise. The dynamic response calculation of slopes and spectrum analysis show that rock slopes have the characteristics of broadband reaction system. In the crest of single-faced rock slope，the amplification factor reaches the maximum value，and is generally less than 2.0. Compared with the results of the seismic input of traveling wave effect，those of time-space consistency input are conservative. Moreover，the influence of seismic wave spectral characteristics on the amplification factor is studied. In the seismic design，amplification factor should be determined by design earthquake group of site at which slope is located. A parameter that has the same dimension with period is introduced in order to comprehensively reflect the influence of slope height，gradient，and rock mass wave velocity on the amplification factor in the crest of slope. Furthermore，Taft wave and El Centro wave are specified to calculate the spectrum curve of horizontal amplification factor in the crest of slope. The envelope analysis indicates that the amplification factor in the surface of slope is less than 1.85. The results of this study can provide a theoretical basis and technical support for the seismic design of homogeneous rock slope.

The transparent tri-axial compression servo-control test system is introduced. It is composed of axial pressure loading system，confining pressure loading system，transparent tri-axial compression chamber，loading controlled system，data acquisition system，image acquisition system et al. The maximum axial load is 500 kN；and the maximum confining pressure is 10 MPa，and the dimensions of test cylinder samples are Φ25 mm×50 mm. There are several advantages of this system：(1) A wide loading rate can be realized for investigate loading rate dependency of rock. (2) Many kinds of load forms can be completed on this servo-controlled system，cooling system is cancelled after hydraulic source modified. (3) A warning trigger is designed for enhance safety during test. (4) A image acquisition system is designed for measure deformation of specimen and the influence of end-effect can be eliminate with this method. (5) Based on the images, the evolution of crack can be observed and described in three-dimensional stresses.

A series of indoor impact tests were carried out by a self-developed rockfall impact testing system. The coupled effects of different factors，such as the rockfall mechanical property，the impact velocity，the incidence angle and the sample size，on the rockfall impact fragmentation mechanism and the rockfall trajectory characteristics were fully investigated. The results show that the mechanical property and the impact velocity are the two major factors that determine the rockfall fragmentation during the impact upon the slope surface. The fragmentation degree of rockfall increases with the growth of impact velocity while decreases with the improvement of rockfall mechanical property. Moreover，there is a normal velocity threshold beyond which the rockfall fragmentation occurs. The threshold decreases with the deterioration of rockfall mechanical property. Furthermore，the impact incidence angle will greatly influence both the rockfall fragmentation and the energy restitution coefficient. Fragmentation of rockfall due to the impact will not only slightly decrease the energy restitution coefficient but will also increase the velocity of some fragments, which may lead to adverse effects on the protective structure.

According to the supporting characteristics of powered support，this paper constructed the elastic foundation-beam model where the powered support groups are treated as elastic foundation，derived the formula of supporting resistance and roof deflection. Based on which，this paper studied the key parameters，such as the different stiffness of powered support，roof rock，roof thickness，mining height，beam end conditions and so on，how to influence the roof subsidence displacement and supporting resistance，analyzed the relationship between the roof deflection and the length of the mining face，and explained the pressure characteristics of the normal length mining face and the pressure law of the super length mining face. Results show that the elastic foundation calculation model has practical value，it can reveal the supporting resistance of powered support groups，calculate the change of roof deflection and explain the law of roof rock broken.

There are legacy many types of coal pillars during mining the Jurassic coal seams in Datong mining area，that have important influences on strata behavior of underlying carboniferous coal seam. The condition of forming inverted trapezoid island structure in overburden structure is determined by analyzing structural characteristics of legacy stacked coal pillars in Jurassic coal seams using the method of ratio discrimination for multi-coal seam mining and limit equilibrium theory，the mechanical model of inverted trapezoid island structure is established and the quantitative influence of different sizes of stacked coal pillars to the coal seam of underlying carboniferous is analyzed. The theoretical analysis shows that the inverted trapezoid island structure leads to the stress field of carboniferous coal seam increasing 91%–259% than in-situ stress field when the width of coal pillar is between 30–120 m，and the influence of inverted trapezoid island structure to carboniferous coal seam become maximum when the width of coal pillar is 80 m or so. The microseismic monitoring shows that the microseismic events have a large distribution density and with higher energy levels(10⁶ J) when the 8104 working face of carboniferous coal seam through the area of stacked coal pillars. The theoretical analysis and field monitoring have good consistency and the research results can provide a theoretical support for the roof management and dynamic disaster prevention etc when Carboniferous coal seam through Jurassic legacy large coal pillar.

Rockbursts induced by instability of super-thick magmatic strata presents a serious threat to mine safety and production. This paper investigates the rockburst mechanism induced by instability of super-thick magmatic strata in Wanglou coal mine using field monitoring，numerical simulation and theoretical analysis. The main results are as follows (1) The rockbursts in island longwall panels induced by instability of super-thick magmatic strata can be classified into two types，spontaneous type and induced type. Spontaneous rockbursts occur due to the overstressing of the instable super-thick magmatic strata and the overburden. Induced rockbursts occur due to the dynamic loading from the movement of super-thick magmatic strata. (2) The criterion for overall burst instability of island longwall panels was proposed. Using the criterion，LW12310 at Wanglou coal mine was designed into large-width island longwall panel to transform the overall rockbursts into local rockbursts. (3) Corresponding measures were developed according to local rockburst mechanism，which agreed well with microseismic and stress monitoring results. The research results provide a practical approach for rockburst prevention of island longwall panels under super-thick magmatic strata.

Deformation，fracture and instability of surrounding rock occur easily in expansive soft rock roadways due to its high clay mineral contents. Under the hydraulic action and high geostress，the clay minerals will show a strong hydrophilic expansibility and a weak resistance intensity. A case study combining with situ conditions of main haulage roadway in Xiaotun coal mine was performed. After geological surveys，field observations and laboratory tests，we find that the seepage action，weathering action，slaking durability and clay mineral contents all are reasons contributing to the deformation and instability of roadway surrounding rock. A combined support system of Full-closed steel grid frame + Wire mesh + Bolt + Shotcrete/Pouring concrete is put forward in this paper. The superiorities of the full-closed frame design are demonstrated，and the spacing between frames as well as the length of the bolts is optimized by numerical simulation. Meanwhile，catchpit is adopted to govern the water-inrush of roadway floor successfully. Finally，the full-closed steel grid frame-oriented combined support system effectively control the deformation of surrounding rock，therefore has a reference significance to similar expansive soft rock support engineering.

Earthquake-induced landslides had complex regularity and were hard to forecast. Traditional susceptibility techniques of earthquake-induced landslides had simple sampling method. The differences from susceptibility analysis of earthquake-induce landslides were done by applying different sampling strategies. The polygon buffer zone was selected as sampling zone，and landslides zones and the sum zones of above two zones were used as comparison. Taking Baosheng in Lushan earthquake occurred on April 20，2013 as the research area. The factors were extracted by sampling method. Then a two-class SVM was trained for calculating susceptibility index. Finally，landslide susceptibility map was done. Statistics，receiver operating characteristic curve and seed cell area indexes were used to analyze the results. The Results of polygon buffer zone were as follows：accuracy of landslide was 94.44%，the area of receiver operating characteristic curve was 99.1%，the seed cell area indexes were best. The result showed the sampling strategy of polygon buffer zone had obvious advantage. So the sampling strategy is feasible and better，it contribute to improve the accuracy of seismic landslide susceptibility analysis.

The nonlinear characteristic of the slope stability problem is difficult to be accurately described by the traditional calculation methods，so a slope stability analysis method based on the harmony search(HS) and the relevance vector machine(RVM) is proposed. Considering the characteristics of small sample，nonlinear，high dimension of the slope safety factor prediction，the RVM is employed to quickly calculate the higher accuracy prediction and the posterior probability distribution，and then the confidence interval is established. Since the prediction effect of the RVM depends on the kernel function and its parameters，the mixed kernel function whose generalization and interpolation ability are strong is introduced；the latin hypercube sampling(LHS) is used to initialize the harmony memory；the parameters of mixed kernel function are optimized by the HS. The slope stability analysis method based on the HS-RVM is established with Matlab program，and minimizing mean absolute error(MAE) is used as an optimization target. The application examples show that the HS-RVM gives fully play to the computing power of the HS and the RVM；the HS-RVM is easy to use and has the advantages of high accuracy，high speed；it has good application in the practical engineering calculation.

Taking the protective engineering of thermal probe group in shallow buried section of Jiangluling tunnel in Road G214 in plateau permafrost regions as an example，based on the study of the characteristics of the ground temperature change and the change of the freezing thawing circle under both the natural condition of the tunnel and the protection of the thermal probe group，the engineering effect of using thermal probe group to initiate active thermal protection on shallow buried section of tunnel in plateau permafrost regions was evaluated. The research shows that，under natural conditions，the range of freeze-thawing circle caused by tunnel construction is larger than 2.2 meters，and the refreezing time is more than 4 years. Under the protection of the thermal probe group，in Jiangluling tunnel left exit hole，the artificial permafrost upper limit evaluates elevate 0.5 meter，and the refreezing time of freezing thawing circle in tunnel top area is 1 year，while its counterpart in surrounding area is 2–3 years. The ground temperature variation is overall similar to the sine and cosine curve. Specifically，the ground temperature is relatively high in warm season and low in cold season，and it decreases in the corresponding period every year with time going by. Elevation results show that，utilizing thermal probe group to initiate active thermal protection on shallow buried section of tunnel in permafrost regions is an effective engineering measure to protect the permafrost environment of the tunnel. It can quickly erase the thermal interference on the permafrost surrounding rock of the tunnel caused by construction and maintain the stability of the permafrost surrounding rock，simultaneously create frost proof curtain on the surrounding rock to reduce to tunnel structure，revent the water above frozen layer from infiltrating into the tunnel structure.

Research on calculating method for loose load of deep-buried large cross-section road tunnel has been done through numerical simulation and theoretical analysis method. Evolution rule of Slumping arch in deep-buried large cross-section road tunnel excavation by steps is analyzed by numerical method with the strain-softening model. The result indicates that excavations of large cross-section tunnel by steps can effectively control the slumping arch expansion，slumping arch of tunnel is the accumulation of that of headings，and traditional method can be used for calculating the loose load of heading in the process of the excavation，but not for that of large cross-section tunnel. So，the calculating method for loose load of deep-buried large cross-section tunnel in the process of excavation by steps is introduced and put into use. It is based on the state design method，carried out with the means of dynamic design，and fully embodies the role of temporary support. By compared with the measured data of Malin tunnel，it indicates that high accuracy can be reached with the method applied to calculate the loose load of deep-buried large cross-section road tunnel. These research results can provide design basis for supporting parameters determination of the similar tunnel.

In order to evaluate the treatment effect of grouting for the tunnel and underground engineering geological disasters and reduce the risk of excavation，a comprehensive evaluation method of grouting effect was proposed. Based on grouting capacity analysis，inspection hole analysis，P-Q-t curve analysis and geophysical detecting method，the main influent factors of grouting effect were analyzed and ascertained. Analytic Hierarchy process(AHP) was applied to establish hierarchy model of grouting effect evaluation index system，and the evaluation factors were quantitative. Fuzzy comprehensive evaluation was used separately to evaluate factors of secondary and primary index. Grouting effect evaluation grade which includes excellence，good，medium and disappointment was established by analyzing evaluated result. The evaluation system and grade standard was adopted to evaluate the treatment effect of Jiangxi Yonglian tunnel F2 fault fracture zone curtain grouting，the evaluation result agrees well with the situation of tunnel excavation. It was preliminarily realized a change from qualitative and empirical to scientific and half quantitative. The research result can be applied to the similar projects.

Spherically weathered granite(commonly known as the“boulder”) is the remnant of a granite body which has been unevenly weathered. Their existence poses a serious operational risk to the subway shield tunnel construction efficient and accurate detection of boulder has been a difficult problem in geotechnical investigation for subway shield tunnel. Using self-determined sparker and geology expert analysis method，sonic wave is created and received in the drills around the detection region. By the difference of longitudinal wave¢ speed in the boulder and other geological body，first arrival time is recorded and explained，and a 3D velocity field of sonic wave is produced by an inversion algorithm，which can describe the geological structure of the detection region. Taking the boulders survey of a certain subway as an example，validity and reliability of this method is verified. The results demonstrate that the cross-hole sonic computer tomography is a very effective technique for“boulder”detection and mapping. Thus，sonic computer tomography can successfully detect similar geological investigation problems and provide scientific basis for the follow-up construction.

Aiming at lack study for mechanical parameters of cataclastic rock mass in sliding zone of Daguangbao landslide，a new method for obtaining mechanical parameters of rock mass is proposed based on the improved Hoek-Brown criterion. Firstly，the value of geological strength index GSI should be quantized by rock mass basic quality index BQ，surface rating SR，surface condition rate SCR and joint condition factor J_c. On this basis，an improved formula of disturbance factor D through rock mass basic quality index BQ was established. By field investigation and laboratory test of rock mechanics，the improved method is substituted into Hoek-brown criterion，and then the mechanical parameters of cataclastic rock mass in sliding zone of Daguangbao landslide is evaluated. Compared with the E. Hoek method，the mechanical parameters of rock mass obtained by the improved method are relatively small，which is closed to the previous suggestions. It proved that this method has a definite rationality.

The 3D laser scanning technology makes up for this shortcomings which can be used to obtain the spatial information of objects rapidly，precisely and comprehensively. By using of 3D laser scanner，the spatial information of surrounding rocks and lining of the Changheba #2 flood discharging tunnel is sampled，and the improved ICP algorithm is used for point clouds registration，then according to the surrounding rock mass and lining surface features，3D excavation tunnel model and lining model are established by delaunay triangular meshes algorithm and NURBS algorithm，respectively. Based on the Boolean logic operation between established models and design models，the over-under-excavated values are measured accurately，and the measured results indicate that，the tunnel over-excavated degree is influenced by the geological condition and the quality of rock masses. Through the analysis of shape deviations at four lining tunnel model segments by comparing with design sections，the result shows that the deviation of lining shape relate to not only pouring quality but also excavation quality，besides，the influence of lining deformation can not be ignored. Measurement results show that the shape deviations are well controlled and the maximum deviation is less than 10 mm，which are meeting the design requirements.

Aiming at the problem of shield tunnel segment uplift during tunnel construction in variable composite formation of Nanning Metro，a sectional statistical analysis on the measured uplift data of a metro shield tunnel is performed and the mathematical distribution characteristics of the uplift value for the typical stratigraphic sections of silty sand-gravel，sand，mudstone-silty mudstone and silty clay are obtained respectively. Then the ruler for the main uplift factors such as the grouting pressure，grout proportion and the actual slag discharge is investigated and the cause of segment uplift in the typical stratigraphic sections is revealed. Then based on the known main factors that influence the tunnel uplift，the longitudinal equivalent continuous beam model is applied to predict and analyze the segment uplift. The results show that the uplift value for the typical stratigraphic section follows normal distribution approximately with respective mean mainly in 30–60 mm. Formation characteristics and tunnel depth have important influence on segment uplift. The uplift value for sand is smaller，while that for silty sand-gravel，mudstone-silty mudstone and silty clay is larger. Synchronous grouting grout proportion and grouting pressure are the main construction factors affecting the tunnel uplift. The stability for sand and gravel stratum is disturbed by over-excavation and large uplift is caused. The overlying gravel is disturbed by over-excavation in mudstones，further exacerbating the influence for the grout pressure，swelling force and squeezing force to tunnel of "earth-carrying" effect on the segment uplift. The results of the equivalent beam model and the field measured data match well and the suggestion of using the model with existing data feedback from field to predict the value of uplift and test construction parameters and measures so as to guide the determination and adjustment of shield construction in the field is proposed.

Guangxi section of high-speed railway from Guiyang to Guangzhou，located in the northeast part of Guangxi basin，is the high-speed channel to link“the Belt and Road”. In order to explore the in-situ stress state of project district and provide basic data for the design of tunnels，the hydraulic fracturing stress measurements of 8 boreholes in 5 different regions were carried out in the northeast of Guangxi Basin. The result shows that the direction of the maximum horizontal principal stress presents NNW-NWW，which is consistent with the regional tectonic stress field. The grade coefficients of the maximum，minimum horizontal principal stresses are smaller than the average in situ stress gradient of China. The relative size of triaxial principal stress at the depth over 300 m tends to S_H＞S_h＞S_v which is prone to reverse faulting；the relative size of tri-axial principal stress at the depth below 300 m tends to S_H＞S_v＞S_h which is prone to strike-slip faulting. The value of lateral pressure coefficient and m_m(the ratio of the maximum shear stress to the average principal stress) in the measured area indicates that the fault in measured area is in a steady state，which also shows that the northeast part of Guangxi basin is the area with stable structure.

In order to optimize wellbore shear failure criteria，this article，comprehensively，evaluated the application characteristics of Mohr-Coulomb criterion，MG-C criterion and E.MG-C criterion. Combining with stress distribution around the borehole inelastic strata，we investigated the wellbore stability critical bottom hole pressure variation with azimuth and inclination. Results show that the predicted pressure of M-C criterion which omits the intermediate principal stress is partial conservative，while the prediction results of linear MG-C criterion get the lowest collapse pressure；the results of E.MG-C criterion，which considering nonlinear rock failure characteristics in the high-stress area，have a middle value，but its prediction collapse pressure of wells with high angle is lower than the result of MG-C criterion. This feature reflected the influence of nonlinear rock failure characteristics to wellbore stability. Under altered in situ stress states，the optimal well trajectory always located in the maximum and minimum principal stress plane and parallel or inclined to the direction of maximum stress. The in situ stress distribution and the actual space state of the borehole also largely determine the stability of the borehole. The research in this paper is useful to provide more accurate and comprehensive advices.

The discontinuity spacing is an important parameter to characterize the integrality of rock mass. Due to the complexity of the geological processes leading to the development of rock discontinuities，exponential and lognormal distributions can not adequately describe the discontinuity spacing in the field. With the discontinuity spacing data，the maximum entropy principle is applied by an energy balance to derive the discontinuity spacing distribution，and the obtained maximum entropy distribution is unbiased and consistent. A three dimensional discontinuity network is generated by Monte Carlo simulation. The discontinuity spacings are calculated along 5 different scanlines. The maximum entropy distribution and exponential distribution are used to estimate the discontinuity spacing distributions. Then，K-S tests are used to test the goodness-of-fit to the spacings. The sampling data of discontinuity spacing from Maluanshan tunnel are analysed and estimated by the proposed method. The results show that the maximum entropy distribution exhibits the better performance compared to exponential and lognormal distributions.

A simplified analysis model and complex models with consideration of the effects of topography，discontinuous geological plane were established and applied to the underground caverns of Dagangshan hydropower station under construction. The finite difference software FLAC is used for the seismic response analysis of surrounding rock mass of under ground caverns. The result shows that the mountain topography has some influences on seismic displacement and acceleration of upper surrounding rock mass，which mainly be  imposed P-wave vibration loading. The effect of the weak structural plane which strengthening S-wave shear to the surrounding rock mass，is relatively remarkable on the earthquake response of caverns，and the effect zone of it is limited to vicinity of cutting surrounding rock mass. The effect regularity of the geological structural plane is different on earthquake waves with different frequency components.

Stratum permeability affects the consolidation of shield tunnel simultaneous grouting，thus affecting the segments uplift during construction period. Since the analysis of shield tunnel segment uplift during tunnel construction does not consider the impact of strata permeability，assuming the grout of simultaneous grouting as Newtonian fluid and the soil as porous media and applying the theory of penetration mechanics and fluid mechanics，a calculation method for the consolidation time of simultaneous grout under the condition of filtration effect in permeable stratum was proposed. Then the equivalent continuous beam model for shield tunnel segment uplift analysis during tunnel construction was revised by putting the consolidation time and the properties of simultaneous grout，excavating velocity into the length of unconsolidated zone in the equivalent continuous beam model. Thus an equivalent beam model for shield tunnel segment uplift calculation considering the consolidation properties of simultaneous grout under the condition of filtration effect in permeable stratum was established and FEM programing was employed to solve this model. The rule of shield tunnel segment uplift during tunnel construction in stratum of silty sand and cobble，sand and silty clay in Nanning was investigated based on this model. And the result shows as follows：The equivalent beam model considering the effect of stratum permeability further reveals the mechanism for the formation characteristics influencing segments uplift. Besides，the calculation results match well with the measured data in situ and the model is more suitable for segment uplift analysis in different permeability stratum. Meanwhile，we draw the conclusion that the weaker the stratum permeability，the longer consolidation time for simultaneous grout，the longer dissipation time for simultaneous grout pressure and the greater the magnitude of tunnel segment uplift.

The thermal probe method for measuring the thermal conductivity of 4 red clays in Guangxi was used to obtain the relationship between the thermal conductivity and water content of red clay. Then the common calculation models was had simulation analysis with the Composite Medium Theory in order to select out the appropriate calculation models which can be used to predicted the thermal conductivity of red clay effectively. On this basis，the calculation value of solid thermal conductivity of red clay in those calculation models was discussed according to the mineral composition analysis. The results show that the thermal conductivity of the red clays increases with the increasing of volumetric water content at the same dry density and the critical water content is a demarcation point. The increasing rates are different in these two sections. It is found that the thermal conductivity of red clay can be calculated into two subsections by Effective Medium Theory(EMT) model and Parallel model. The thermal conductivity was predicted by the EMT model when the soil water content is lower than the critical value，and by the Parallel model when the soil water content is higher than the critical value. Finally，the method for taking-value of solid thermal conductivity of red clay with Difference Effective Medium Theory have a comprehensive consideration about the influence of mineral compositions of red clay on the solid thermal conductivity，and the calculation results are much more approximate to the practice.

5 methods and their applicability for estimating the maximal surface settlement(S_max) induced by subway construction were summarized. Based on the large numbers of surface settlement measurements，the variation regularities of S_max，the coefficient of settlement tough width(k)，volume loss(V_l)，the gap parameter(g) were obtained. The results show that：(1) the empirical method can be widely and well used on the basis of measurements，the analytical method is only apply to the homogeneous soil and undrained conditions，there are the regional differences with semi-empirical method. (2) Besides the special soil conditions with preceding reinforcing methods，the general soil conditions，H/D and construction technologies are the major influence factors on the S_max. S_max is inversely correlated with H/D，the average value of S_max is between －11.5 mm and －31.3 mm with shield tunneling method，however，the average value of S_max is from －13.0 mm to －41.6 mm for the shallow tunneling method，it indicates that the former method is superior to the latter. (3) The relation between S_max and g can be expressed as S_max = (－0.28 to－0.71)g，and S_max/g versus H/D can be described with modified Atkinson formula(= 0.15–0.28)and Clough formula(=－0.55–－1.11). Through the systematic summarization，the estimation methods and their applicability of S_max can be completely understood and provide a scientific reference for the similar subway projects. 

A series of seepage tests under coupled compression and shear were performed on a typical clay by a newly-invented hollow cylinder apparatus. The permeability characteristics of the clay before，during and after large shear deformation were studied comparably. It was found that the magnitude of current consolidation stress controls the changing of the permeability coefficient and seepage stability of the clay during shearing. When the exerted vertical stress is greater than the preconsolidation stress of the specimen，the shear plane is compacted during shearing，no concentrated leakage is found in the specimen，and the overall permeability coefficient decreases slightly after shearing. In contrast，when the exerted stress is less than the preconsolidation stress of the specimen，the shear plane dilates and opens gradually during shearing，and then becomes a channel of concentrated leaking. Although the open shear plane can heal itself during steady seepage，its permeability coefficient after healing increases remarkably. For the normal consolidated specimen，the seepage stability have no significant change. For overconsolidated specimen，the seepage stability decreases significantly，and the pattern of seepage failure is hydraulic fracture and crack scouring when raising the water head rapidly.

Displacement changes of the soil around the squeezed branch pile directly affect its vertical bearing capacity， while， traditional test methods are different to obtain the deformation characteristics of soil around the pile. The transparent soil model test was carried out，which is based on transparent materials and particle image velocimetry(referred to as PIV) technique，and the soil displacement around the branch pile and soil around equal section pile under axial load are tested by non-intrusive measurement. Test results show：compared with the equal section pile，squeezed branch pile can increase the bearing capacity by increasing the scope of the soil deformation displacement field and inducing the strength of the soil deformation displacement field. The soil displacement around the branches and that under the pile tip both have radial features，which shows the branch and the pile tip have the same bearing capacity，and the branches share a part of the pile load and change load transfer law. According to the soil displacement field around the branch， the soil displacement under the branch has a negative effect on the lateral frictional resistance of the pile. The position and distance of the branches have a great influence on the soil displacement field of around the branch pile through the test，and the distance between the branches should better be more than three times of the branch diameter.

Physical and mechanical properties of oil contaminated soil is poor，thus improve its strength is the premise to reuse in engineering. Saline soil contaminated by oil was investigated and lime and fly ash were chosen as solidified materials. Unconfined compressive strength was analyzed to quantify the effectiveness and also to factors. Results indicate that：(1) lime and fly ash solidification can improved significantly the mechanical properties oil contaminated soil，the strength of solidified soil(12% lime and 20% fly ash) meets the strength requirements to secondary highway up and down embankment and foundation replacement in Specifications for Design of Highway Subgrades (JTG D30—2015)，as oil contaminated level less than 8%，the strength reach to requirements of expressway and arterial highway. (2) Stress-strain curve of solidified soil include linear load，nonlinear rising and decline phase，and it presents strain softening damage. With the increasing of oil contaminated level，the plastic deformation is enhanced. (3) Strength of solidified soil decreased as oil contaminated level sintensified，oil contamination reduces the reaction rate，and then weakens solidification among lime，fly ash and soil particles. (4) For oil contaminated level within 12%，the suitable solidified parameters are 12% lime，22% fly ash andcuring period of 28 d.

To address the influence of multiple layers of reinforcement on geosynthetics reinforced pile supported (GRPS) embankment，based on the hypothesis of soil arching and strain of geosynthetics，the formula was deduced for calculating the pile efficacy in this paper. Firstly，based on limit-stress equilibrium of soil arching and two-dimensional soil arching model with concentric arches，the theory formula was deduced for calculating the pile efficacy upon geosynthetics. Secondly，the shape of geosyntheticsdeformation between pile caps was assumed as arc，the contribution of deformation of geosynthetics upon pile caps to strain of geosynthetics between pile caps was considered，and then the calculation formula for strain of geosynthetics was deduced，which is well suited for GRPS embankment with sparse piles and large pile caps. Thirdly，the deformation of bottom geosynthetics induced by filling below geosynthetics and soil stress between piles was estimated，and then the mathematical relationship of deformation between the bottom geosynthetics and the others was proposed. Lastly，tensile forces and vertical components of geosyntheticswere calculated by aforementioned strains，and the formula was deduced for calculating the pile efficacy under geosynthetics. This method could be applied to plie supported embankment reinforced by single or multiple layers of geosynthetics. The calculation results were shown to provide satisfactory agreements with testing datum.

Triaxial shear tests on RSM Poisson¢s ratio with 10 kinds of rubber content and four kinds of confining pressure are accounted. Results indicate that：(1) Poisson's ratio of RSM with low rubber content shows similar behavior with pure sand，and Poisson¢s ratio values greater than 0.5 is observed due to dilatancy effect. For RSM with medium rubber content，its Poisson¢s ratio increases with axial strain or stress level monotonically. For RSM with high rubber content，the Poisson¢s ratio of it decreases firstly and then increases with axial strain or stress level. (2) The initial Poisson's ratio of RSM shows V type variations with rubber content，that is it decreases first and then increases with the increase of rubber content of RSM，and the turnover rubber content is proved between 35 percent to 40 percent. (3) The Poisson's ratio of RSM approaches to 0.5 in damage stage. (4) Confining pressure influences RSM Poisson¢s ratio slightly. The mechanism of RSM Poisson's ratio variation with rubber content and stress level is attributed to different stress bearing skeleton form by sand or rubber particle in RSM mixtures. Finally，empirical equations for estimation of RSM Poisson¢s ratio dependent on stress level are proposed，and comparison with tests results demonstrates that the proposed equations could simulate RSM Poisson¢ ratio properly.

By use of the indoor model test method，the tests have been carried on between the composite foundation of pipe-pile with cap and holes，which are three kinds of arrangement holes，and the composite foundation of pipe-pile with cap and without hole，the character rules of soil pressure between two pile caps，soil pressure under pile cap，pile-soil load sharing ratio and pile-soil stress ratio of the composite foundation of all piles have been analyzed comparatively. The test results show that the soil pressure between two pile cap of the pipe-pile with holes is greater than that of pipe-pile without hole，the pile-soil load sharing ratio and the pile-soil stress ratio of the composite foundation of pipe-pile with cap and holes is smaller than that of composite foundation of pipe-pile with cap and without hole，the soil around pipe-pile can play the more role of the load sharing in the composite foundation of pipe-pile with cap and holes. These results can confirm that the pore water can go into the inner cavity of the pipe-pile with holes through the pile holes，reducing soil water content，improving the shear strength of soil. These results can also provide the test basis for theoretical study of composite foundation of pipe-pile with cap and holes，and the guidance for its application.

Based on the structure-foundation-soil interaction，the model experiment is used to study the tall and low building with thick raft foundation. The distribution regularities of foundation settlement，the compression settlement of soil mass，contact pressure，interaction of tall and low building and deformation control are summarized. The test result shows that the maximal value of the interaction regions for the tall building and low building is 3 spans. the major thickness of compressed layer for the tall building is 0.6 times foundation width，the integral flexure of the tall building is decided by it¢s structural rigidity and load，the inclination of the tall building increase with the increase of the differential load. So the inclination may be the important deformation control for the complex high-rise building.

To investigate the deformation characteristics of small width-depth ratio foundation pits，23 case histories of wall and ground movements in Shanghai soft soils were collected and analyzed. Based on the field data，several major findings were obtained：(1) The maximum horizontal wall displacement() of small width-depth ratio pits is smaller than that of regular pits，with an average value of (excavation depth). (2) The location of maximum lateral wall deflection(H_d) ranges from －6 to +6. (3) Maximum ground settlement() of small width-depth ratio foundation pits is smaller than that of regular pits，with an average value of . (4) Small width-depth ratio pits have stronger anti-deformation abilities than regular pits. (5) andof small width-depth ratio foundation pits supported by sheet pile wall，soil mixing wall and bored pile decrease in turn. (6) The envelope line of ground settlements of small width-depth ratio foundation pits is ladder-shaped and it also shows that influence scope of ground settlements adjacent to small with-depth ratio pits is smaller than that of regular pits. (7) The average value of  is 0.96，which is mainly controlled by soil conditions.

Loose rock-soil aggregates(LRA) is widespread in nature environment and practical engineering. A kind of LRA that composed by strong weathered slate is selected as the research object. Firstly，the sample preparation method for LRA is achieved successfully，then based on large-size stacked ring shear apparatus，a series mechanical tests for LRA under different relative density(D_r) and different dry and wet state is conducted，the research shows that，because the restraint effect and mechanical bite among LRA is weak，the peak value in stress-strain curve is not significant，the big deformation mainly composed by interparticle friction and rolling；for the three D_r(0.30，0.35 and 0.40 respectively) conditions in experiment，when LRA keep dry state，the friction angle slightly increased from 13.18°(D_r = 0.30) to 13.97°(D_r = 0.40)，and cohesion slightly decreased from 6.95 kPa (D_r = 0.30) to 4.90 kPa (D_r = 0.40)， it means the strength of LRA nearly keeps stable in this loose range，and when the sample is wet or submerged in water also meet to this law；the peak shear stress of dry LRA is much higher than that in wet and submerged in water，the water sensitivity characteristic is obvious；D_r = 0.40 is selected as a case study, based on a comparative test，it¢s clear that in researching engineering properties of LRA，stacked ring shear test is more advantages and applicability than conventional triaxial test. This research preliminarily reveals the strength and deformation characteristics of LRA，obvious water sensitivity of LRA are very useful in quantitatively explain the mechanism for large deformation and failure of loose deposit and landslide.

From the angle of strata-deformation ability，this paper is aimed at evaluating the promotion value of a new kind of quasi-rectangular shield method. Based on the domestic first quasi-rectangular shield tunnel worksite test facilities，this paper proposes the finite element method which can simulate the physical process of the interaction of soil and quasi-rectangular shield shell to study the deformation mechanism of surrounding strata. An in situ test project with a complete testing program was then established. Finally，the surrounding strata deformation pattern under the interaction of soil and shield shell has been built. The results of the study prove that： strata deformation pattern on the vertical direction of shield tunneling can be divided into compaction expansion stage and resilient contraction phase，and strata deformation pattern on the direction of shield tunneling is greatly influenced by quasi-rectangular shield back earth on the flat shell.

In order to quantitatively study the characteristic that the permeability coefficient of silty clay varies with the stress，the permeability coefficient of different dry density silty clay under different effective stress levels were measured by triaxial permeability test，and the relationship between permeability coefficient and dry density and stress were analysis. Results showed that the saturated density of silty clay increases with stress，and the increase amplitude were 5%–9% when the stress was 400 kPa. The permeability coefficient k was great effected by effective stress σ and decreased 1 to 2 orders of magnitudes when the stress was 300 kPa. The lnk presented a significant linear correlation withand. An expression for permeability coefficient of silty clay considering dry density and effective stress was proposed based on the results. And the equivalent vertical and horizontal permeability of silty clay layer calculation method and the most representative location of soil sample were derived.

In order to explore the shear strength of the different types of rainforest tree straight roots and soil composite，the research group adapted direct shear tests on shear planes with different the number of root，root diameter and root distribution by designed large complex root-soil direct shear apparatus。Through the electric automotive jack，to push against the upper shear box at a constant speed，in the process of the test always keep a record of the date：jack thrust size，the relative displacement of straight root and shear box，displacement of shear box and so on. Experimental results show that the distribution types of root，root diameter，the number of root and shear depth can effect the shear strength and the shear strength index of the root-soil composite；the root of vegetation has a positive effect on the reinforcement of soil，The trail lays a foundation for more in-depth research of subsequent tree roots of small landslide governance.

：Uniaxial tensile method test is used to obtain tensile strength of undisturbed and remolded loess by dry-wet circulation experiment. The relationship among the tensile strength，water content and dry-wet circle number is discussed. The attenuation mechanism of tensile strength of loess is analyzed. It is shown that tensile strength of loess nonlinear increases with decreasing water content. Tensile strength of undisturbed and remolded loess decreases with increasing number of cycles and finally reaches to a constant state. The sum of tensile attenuation value and tensile structural strength is equal to tensile attenuation value of undisturbed loess. It is proved that the original structure of undisturbed loess is broken by many times of dry-wet cycles，and its tensile structural will disappear. The dry-wet cycle is not only makes the same as the adsorption strength of undisturbed and remolded loess，but also makes the soil to be a stable and reliable equilibrium，and has the same structure of soil mass. 

Based on the Rayleigh-Love rod model，the longitudinal dynamic impedance of a large-diameter belled pile is theoretically investigated considering the construction disturbance effect. First，the virtual soil pile model and the shear complex stiffness transfer method are adopted to simulate the vertical inhomogeneity of the pile end soil and the radial inhomogeneity of the surrounding soil caused by the construction disturbance effect，respectively. Then，the shear complex stiffness at the pile-soil interface is solved and is substituted into the governing equation of the pile. Meanwhile，the analytical solution for the dynamic response at the pile head is obtained in the frequency domain by virtue of impedance function transfer method and Laplace transform method. On this basis，comparisons with published solutions are carried out to verify the reliability of the present solution. Finally，by means of parametric analysis method，the influence of pile parameters and the construction disturbance effect on the complex impedance at the pile head is investigated within the low frequency range concerned in the design of dynamic foundation. The results show that：(1) the influence of the radius of the enlarged base on the complex impedance at the pile head is much greater than that of the length of the enlarged base. (2) The dynamic characteristic of the large-diameter belled pile is greatly affected by the construction disturbance effect，besides，the influence of the disturbance of the pile surrounding soil is greater than that of the disturbance of the pile end soil.

The physical and mechanical properties of the dielectric materials mainly depend on shapes of particles in granular media. Therefore，in order to reveal the differences of physical and mechanical properties between tailings and natural sands，one of best ways is to use microscopy and image processing technologies to quantify four indicators (flatness，roundness，convexity and roughness) which can well quantify the shapes of particles. In this research，four tailings (gold，tin，copper and iron) and two natural sands (river sand and sea sand) are selected for such comparison. Results show that：(1) the flatness of tailings and sea sands decrease with the increase of particle size，which means tailings or sea sands with needle shapes tend to be spherical. (2) The roundness of tailings and river sands decrease with the increase of particle size，which also indicates the shapes of tailings and rover sands tend to spherical shapes. However，the roundness of sea sands decrease with the increase of particle size. (3) The convexity of tailings and sea sands increase with the increase of particle size，which indicates that angularity of tailings and sea sands surface reduce with the increase of particle size. (4) The roughness of tailings，river and sea sands increase with the increase of particle size. 

Based on the monitored ground temperature data of special-structured subgrade of Gonghe-Yushu expressway in Qinghai province，this article analyzed ground temperature variations of foundation soil and subgrade fillings of three kinds of subgrades(XPS insulation board subgrade，crushed rock subgrade and ventilated subgrade)，the changes of artificial permafrost table，the heat flux density near the permafrost table and the asymmetry of subgrade temperature distribution in a comparative way，aiming to study distribution characteristics of ground temperature and cooling effects of three kinds of subgrades. The results indicate that：(1) the temperatures at left and right shoulders of all three kinds of subgrades present a significant increasing trend at different depths. During the observation period，the temperature of XPS insulation board subgrade increases by the largest extent，followed by the crushed rock subgrade and ventilated subgrade. (2) During the initial period after construction，the artificial permafrost tables of three kinds of subgrade rise in different degree, yet declined in the third year. (3) The heat budget of three kinds of subgrade near permafrost table remains a heat absorbing state，the relationship of absorbed heat amount can be listed as：XPS insulation board subgrade＞crushed rock subgrade＞ventilated subgrade. (4) The internal temperature of three kinds of subgrade distributes asymmetrically，featured by high on the left side and low on the right. According to the results，ventilated subgrade is recommended in the construction of expressway in warm permafrost regions. At the same time, we should stick to the principle of differentiated design to reduce the longitudinal cracks and other diseases caused by uneven distribution of ground temperature.