The disturbed stress field in deep mine roadway is closely related to the occurrence of excavation disturbed zone(EDZ). However，the geological conditions of site and the limitation of technology restrict the feasibility of in-situ monitoring to the disturbed stress field in deep mine roadway. Thus，the evolution of EDZ was instead obtained with the in situ monitoring firstly. Secondly，a numerical model was established by back analysis. The model is used to simulate the evolution of EDZ accurately. Finally，the evolution of disturbed stress field during the excavation of deep mine roadway was analyzed with this model. The results showed that the stress values of monitoring spots were not changed basically when the monitoring section was ahead of excavation plane due to the constraining of the rock in front of the excavation plane. When the excavation plane passed the monitoring section，the values and orientations of the principle stresses on the side，roof and floor were changed. The evolution of disturbed stress and EDZ were compared and found that they had some similar characteristics.

Permeability of fracture is sensitive to the dissolution of minerals under the medium temperatures(25 ℃–90 ℃) and osmotic pressures. The flow-through experiments were therefore conducted on the limestone containing a single fracture under 4 different temperatures，25 ℃，50 ℃，70 ℃ and 90 ℃ respectively. The seepage discharge and hydraulic equivalent width of aperture affected by the temperature variation was studied to investigated the permeability characteristics of limestone fracture. During the reaction process，the seepage discharge and the ionic concentration of percolate were measured. The seepage discharge was transformed through the cubic law to obtain the variation of fracture width with time. The experimental results show that the seepage discharge and the hydraulic equivalent width of aperture in the process of temperature rising increase significantly with the time. The hydraulic equivalent width of aperture in the process of constant temperature decreases gradually and finally reaches a stable value. After the increase of osmotic pressure，the width of aperture under the constant effective stress decreases as the increase of temperature. It was found that raising temperature promoted the effect of stress and seepage，and the partial dissolution of seepage channel also changed with the variation of temperature，thus influenced the process of pressure dissolution and free dissolution.

In order to investigate the variation of fractures of pre-static loaded hard rock under the different dynamic disturbance，the fracture toughness tests of sandstone were carried out on three point bending specimen with a straight crack in the center of the red sandstone(SCB) using the electro hydraulic servo testing machine Landmark MTS. Four pre-static load levels(60%，70%，80% and 90% of conventional static fracture load) were selected. The dynamic disturbance tests were conducted by using the sine wave loading. The amplitude of loading were 40%，30%，20% and 10% of the static fracture load and the loading frequency were 1，10，20，30，40 and 50 Hz respectively. Compared with in the conventional static fracture tests，the fracture toughness of rock under different pre-static loads decreased and it decreased linearly with the increase of the disturbance frequency. However，the toughness decreasing effects under the different static pre-loadings are different. The higher the pre-static level，the greater effect of the toughness decreasing. Compared with the conventional fracture displacement，the fracture displacement under pre-static loadings decreased as a whole. The concentrated distribution of disturbance induced fracturing point was found. The fracturing point occurred in the loading stage above the pre-static level when the pre-static load level is less than 90%，while the fracture point occurred in the unloading stage above the pre-static load level when the level of pre-static load is 90%. With the increase of disturbance frequency，the fatigue life span increased firstly，then decreased and finally increased again with an overall trend of increasing. No obvious correlations between the time of fracturing failure，the pre-static load level and the disturbance frequency were found. The cracking effect is about optimal when the disturbance frequency is 10 Hz.

During the excavation of deep tunnel in rock mass，the energy release and dissipation are the important factors which lead to the damage of surrounding rock. The blasting excavation of deep circular tunnel was studied theoretically to investigate the variation of strain energy in surrounding rock under the blasting load with multi-micro-second delays，the repeated disturbance of transient release of geostress，and the coupling effect of these two dynamic loads. The damage range was calculated based on the elastic strain energy criterion. Results show that the strain energy in surrounding rock under the blasting load increases firstly，then decreases and stabilizes finally. The strain energy under the transient release of geostress decreases firstly，then increases and stabilizes finally. The dynamic adjustment of strain energy is greatly influenced by the coupled effect of blasting and geostress release. This effect is reflected most obviously in the two rings of stope holes and a ring holes near the excavation boundary. The blasting load causes mainly the tensile failure of the surrounding rock，while the transient release of geostress results mainly in the compression-shear failure. The existence of the geostress restrains the damage caused by blasting and reduces the damage range of surrounding rock. At last，the correctness of the theoretical method is verified by the measured damage range of diversion tunnels in Jinping II hydropower project.

The excavation of deep buried tunnel with the large cross section reveals many kinds of rocks with different physical and mechanical properties. It is very important to study the process and mechanism of the collapse for the complex lithological compressive rupture zone. The complicated lithological compressive rupture is located in No.3 laboratory of Jinping underground laboratory. The collapse happened there once. It was found through the field geological investigation and mineral analysis that the complex lithology of rock mass and high in-situ stress were the key factor of collapse. The failure mode of rock collapse recorded by video，the failure mechanism obtained by scanning electron microscope and the different lithological rock mass located in spatial distribution indicated that there was an obvious progressive failure characteristics in this collapse and the different lithological rock masses exhibited the different failure mechanisms. The variegation breccia and the corrosion marbles in the southern side wall and tunnel face exhibited the shearing slip failure，and the calcite marble in the northern side wall exhibited the toppling failure due to joint opening，and the mosaic cementation marble，variegation breccia marble and corrosion marble in top arch exhibited the gravitational collapse. The process of collapse recorded by video and the failure mechanism of different lithological rock mass obtained by SEM show：the excavation unloading→the collapsing of the thin layer rock mass around the tunnel→the shearing slip of the rock in the southern wall→the toppling failure of rock in the northern wall due to joint opening→the rebounding of the top arch rock under the unloading of both sidewalls→the gravitational collapsing. The comprehensive treatment measures inside and outside of surrounding rock(initial shotcrete not less than 10 cm thick + grouting bolt with anchor plate + suspended net + shotcrete again) were recommended.

A set of uniaxial compression tests has been carried out on the samples of basalt rock with hidden fissures and the acoustic emission signals have been monitored during the test processes. The failure characteritic of samples under the compression loads are affected by the hidden fissures and the failure mode is primarily the shear-tension failure that the cracks propagated from the tips of hidden fissures，then slide beside the cracks. The hidden fissures cause the stress-strain curve to exhibit a “saw tooth” shape during the failure stage. The average uniaxial compression strength of the tested samples is 106 MPa and lower than the intact aphanitic basalt rock from the same site. The more of fissures within a sample，the lower the strength. The characteristics of acoustic emission signals are affected by the type of strain. The energy acoustic emission caused by the permanent strain has a higher amplitude. The acoustic emission develops steadily before failure，and increases greatly after entering the failure stage. The signal intensity of acoustic emission decreases by the hidden fissures inside the specimens，but the absorption effect dropps when the fissures close under compression.

The strengthening characteristics and the shortcoming of the strengthening methods commonly used at the inner interface of the shield tunnel were analyzed and the textile reinforced concrete(TRC) was proposed to control the transverse deformation. The method of simulating the strengthened layer and interface was presented and validated by experiment. The responses of lateral deformation and joint opening at the top arch were analyzed with numerical analysis in terms of the stiffness coefficient of the formation，the timing of the strengthening construction，the amount of the textile and the arrangement of the reinforcement layer. The mechanism of TRC in controlling the transverse deformation of shield tunnel was revealed based on the analysis of deformation and internal force of the segment. The results of the research indicate that TRC can effectively restrict the horizontal convergence and joint opening. The reinforcement effect is better if the stiffness of ground layers are lower. The increasing in textile layers enhanced the control effect，however，the efficiency of fiber utilization was decreased. The reasonable layout of the strengthening layer was proposed to be set in the tension section of the arch between the inflection points. The longer the strengthening layer，the better the controlling effect.

The shear broken failure of bolts cannot usually be simulated with the FLAC3D. A broken criterion Fs(i)≥Fsmax(i) was thus proposed based on the PILE element. The modified mechanical model of PILE element was established and embedded into FLAC3D. The direct shear tests of bolts and the bolt supporting tests of roadway with coal-rock interface slippage were simulated respectively with original and modified mechanical model of PILE element. The shear load-displacement curve with the modified model presented the shear broken failure characteristics，and the quantitative broken effect was achieved through the shear force judgement. The shear and axial forces of the failed elements of the bolts dropped to zero when the shear broken failure occurred，consequently the shear broken failure of bolt was realized in FLAC3D. In the bolt support with the modified model，the shear broken failure occurred at the bolts around the coal-rock interface，and the bolts at the coal-floor interface failed earlier than those at the coal-roof interface. The greatest calculated displacement at the coal-rock interface with the modified model was 17.5 mm larger than that with the original model，and the result was more realistic. Overall，the range of application of FLAC3D was extended with the implementation of shear broken failure of PILE element with the modified model.

Panoramic digital cameras for boreholes have been widely employed in engineering practice，and a large number of high accuracy images of boreholes have been obtained. The borehole images record accurately the geological features，especially the structural features of the structural planes. However，since the acquisition of these features is usually undertaken manually，the workload is large and the results can be affected by many man made factors. To solve this problem，this paper presents a method of fully automatic identification of structural planes with the panoramic camera images of borehole. In this method，the gray level of images，the gradient and the projection method are employed to distinguish the region and the area of the structural plane occurrence. The standard sine function matching is employed to search the structural plane in the region. The optimal sine curve is screened out and adopted as the feature curve of structure plane. The parameters of the feature curve are analyzed and converted into the parameters of the structural plane required in engineering projects，such as the position，the inclination，the dip angle and the fracture width，etc. The results show that the method can automatically identify the structural plane with the borehole image continuously and quickly and can obtain the corresponding structural parameters accurately. The method is stable and reliable. Compared with the traditional methods，this method realizes the fully automatic identification of the whole structural planes and the extraction of geometric parameters. It improves greatly the working efficiency，and provides an effective solution for the post processing and information acquisition of the borehole image.

The measurement of P-wave velocity and the waveform analysis of coal samples during the whole process of water absorption were performed to study the variation of P-wave velocity and the characteristics of waveforms. The variation of P-wave velocity with the water saturation and porosity were studied. The amplitude-frequency and time-frequency characteristics of the waveforms under the different water saturations were researched based on the FFT and HHT methods. The results show that the P-wave velocity is influenced by the water saturation and porosity at the same time. The P-wave velocity increases nonlinearly as the water saturation increases. The increasing rate of the P-wave velocity increases significantly when the water saturation reaches about 70%. The properties of water and the uniform existence of pore water in the porous structure of coal are the main causes of the increase of the P-wave velocity. The P-wave velocity decreases linearly with the increasing of the porosity of coal. The higher the water saturation，the less affected the P-wave velocity by porosities. It indicates that the water in the coal samples weakens the influence of coal porosity on the P-wave velocity. The waveform frequency distributions differ dramatically during the whole process of water absorption of coal samples. The main frequency moves towards the low frequency nonlinearly with the increase of water saturation. The higher the water saturation and the porosities of coal，the smaller the maximum amplitudes of waveforms are. The energy distribution of wave frequency bands and the temporal changing characteristics of the waveform signals can be revealed by the three-dimensional Hilbert spectrums of energy. With the increase of the water saturation，the proportion of the high frequency component reduces gradually，and the frequency bands with the high energy move to the low frequency. It means that the pore water in the porous coal structure not only speeds up the energy attenuation of all frequency bands，but also makes the attenuation of high frequency components greater than the low-frequency components.

Various factors influence the tunneling are simplified considering the axial symmetry of the composite lining structure. The analytical expressions for the seepage field，stress，and displacement in the surrounding rock and those for the grouting circle，permeable lining，and ordinary lining are obtained according to the principle of effective stress. The seepage discharge，plastic zone，stress，and displacement around a tunnel affected by the different permeability coefficient ratios between the permeable lining and surrounding rock are studied. The reasonable value of permeability coefficient for the permeable lining are discussed. The results show that the grouting circle controls the tunnel seepage discharge well and has a reasonable permeability coefficient and an optimal radius. The grouting circle controls the plastic zone development in the surrounding rock，i.e.，the thicker the grouting circle，the smaller the plastic zone in the surrounding rock. The tunnel seepage discharge and the effective stress in the grouting circle and lining increase gradually with the increasing of permeability coefficient ratio and tend to be stable after the ratio reaches 0.1. Comprehensive analysis on the factors such as the stability of tunnel seepage discharge，the plastic zone of the surrounding rock and the stress around the tunnel indicates that it is relatively reasonable for the permeability coefficient ratio to be greater than or equal to 0.1.

The unloading of excavation and the complexity of in-situ stress result in the variation of static stresses in the surrounding rock. The effect of static stress on stress wave propagation was investigated with the modified Hopkinson pressure bar testing system to measure the stress wave propagation through the long specimens of red sandstone. The dynamic disturbances were approximately equal and relatively small so that the damage caused by the stress wave is insignificant. The axial static stresses were divided into 13 levels. The variation of P-wave velocity，space attenuation coefficient of amplitude，time attenuation coefficient of amplitude，and amplitude attenuation coefficient with the static stress were investigated. The results show that the stress waveforms at different locations are approximately the same when the axial static stress is constant，but there are obvious differences in the wave shapes obtained at the same location under the different axial static stresses. The tensile wave appearing at the tail of stress wave increases with the increasing axial static stress. With the increase of the axial static stress，the longitudinal wave velocity of rock increases rapidly at first，then develops gently，finally decreases sharply. The stresses of 30% and 55% of uniaxial compressive strength are two critical points. Under the same axial static stress，the amplitude of stress wave varies exponentially with the propagation distance and the propagation time respectively. As the increase of axial static stress，the spatial and time response amplitudes of stress wave decrease gradually，and both the spatial attenuation coefficient and time attenuation coefficients have the tendency of rapid decrease-steady development-sharp increase. The amplitude attenuation coefficient ?σs at the same location decreases firstly and then increases with the increasing of the axial static stress，and the ?σs at the measuring points closer to the incident side are more sensitive to the static stress than the ?σs at measuring points farther from the incident side.

The existed solutions on the interaction between the seismic responses of soil and structure have focused on the tunnels of circular cross section. The dynamic analysis for the rectangular tunnel tends to increase in complexity of calculation. An analytical solution of the seismic response of deep buried rectangular tunnel under the action of far field shear waves is derived based on the pseudo static method by using the complex analysis and conformal transformation. The shear and normal stresses in the interaction between soil and tunnel are considered in the solution of the complex function. The accuracy of calculating the conformal transformation function for rectangular tunnel is improved by introducing a correction factor. The accuracy of the analytical method is verified with the numerical model. The parameters influencing the normalized displacement ratio and the variation of the soil stress field for the rectangular tunnel are analyzed as well. The study shows that the accuracy of the analytical solution is improved by introducing the correcting coefficient，which is more close to the numerical solution. The normalized displacement ratio of the rectangular tunnel decreases with the increase of the relative stiffness ratio of tunnel to soil. The normalized displacement ratio increases as the increasing of the ratio of the cross section size. When the cross section size ratio of the rectangular tunnel and the relative stiffness ratio are unchanged，the normalized displacement ratio of the rectangular tunnel increases with the decrease of the Poisson's ratio of the soil. When the cross section size ratio is 1 (Square tunnel)，the change of Poisson?s ratio of soil has little influence on the normalized displacement ratio of the tunnel. The soil stress field around the rectangular tunnel increases with the increase of the Poisson?s ratio of soil. The soil stress field decreases with the increase of the elastic modulus of soil. The soil stress field decreases with the increase of the shear modulus of the liner.

The centrifugal shaking table test with the centrifugal acceleration of 50 g was carried out to investigate the bending moments and deformation modes of the pile group installed slope with intercalated weak layer and to investigate the effect of the inner deformation of slope and the inertia force of superstructure on the pile group foundation. The results showed that the bending deformation of the pile group foundation was controlled by the inertia force of the superstructure under the seismic excitations，and the range is limited around the pile top and take up 26%–28% of overall length of the piles. The modes of bending deformation of the pile group foundation were classified as the uniform type and the non-uniform type，the types with and without the inflection point，the parallel and non-parallel types. The effect of intercalated weak layer on the amplification coefficients of acceleration within the slope is related to the peak values of input accelerations and the amplification coefficients of the weak intercalated layer increased nonlinearly with the increasing of the peak values of input acceleration. Besides，there are obvious differences in the dynamic responses of superstructure and ground surface of the slope，and the differences were increased nonlinearly with the increasing of the peak seismic acceleration and were multiple increased when the input acceleration peak is equal or greater than 0.25 g.

为探究盾构隧道管片接缝对于隧道结构及周围软土地层的动力响应的影响，采用模型试验与数值模拟相结合的方法，借助2种不同的盾构隧道模型——忽略接缝的均质圆环模型与考虑接缝效应的管片衬砌拼装模型，以频域分析为基础，模拟计算列车振动荷载全频域内隧道衬砌结构及周围软土地层的频率响应函数，分析在不同频率荷载作用下衬砌结构的内力分布规律。研究结果表明：在列车振动荷载作用的频域区间内，隧道结构和软土地层的竖向加速度响应均呈现出随频率升高而增强的趋势，在低频段(0～60 Hz)增长迅速，中高频段(60 Hz以上)则增速放缓；管片接缝的存在使隧道结构的动力响应明显降低，最高幅值可达10 dB，但影响范围主要集中于40～200 Hz的中高频率荷载区段；管片接缝对软土地层的动力响应也具有一定的影响，但影响程度远小于隧道结构本身；管片内力主要集中于施加振动荷载的拱底附近，接缝对管片环所受轴力有较为明显的影响，而对结构所受弯矩影响较小。从模型试验与数值模拟计算结果可以看出，考虑列车振动荷载作用下隧道衬砌结构的动力响应时，应充分注意管片接缝的影响。

The temperature field of high speed railway tunnel located in cold region was studied through the research on the thermal insulation design of the tunnel for high-speed railway from Moscow to Kazan in Russia. The aim of this study is to propose a new testing system of modeling to investigate the air temperature field in the tunnel influenced by the varying variables such as the temperature outside the tunnel，the temperature of rock，the speed and the running intervals of trains. The system is typically comprised of five components，i.e.，the driving device of high speed train model，the small-scale tunnel model，the temperature controlling device，and the measurement system together with the train model. Utilizing the programmable logic controller(PLC)，the servo motor driving device of the high speed train model realizes the expected speed of the train model though accelerating，maintaining and reducing the velocity. The polymethyl methacrylate casing is connected by the  flange，bolt and sealing strip and the entire test process is thus visible. The model is extendable in length. The temperature controlling system is composed of devices for outside tunnel and rock temperature and the measurement system consists of a high sensitivity temperature measurement instrument，a wind speed sensor and a data acquisition unit. Typically，the train model according to CHR 380A high-speed train，is made of polymethyl methacrylate as well，with the geometric similarity ratio of the prototype to model 50∶1. The testing results indicates that the deceasing of air temperature of 5 ℃ outside tunnel may increase 104 m of the minus temperature length from the portal and the minus temperature length for the portal reduces by 145 m if the rock temperature increases by 5 ℃. For the tunnel with the train running interval less than 15 minutes, the design of anti-freezing thermal protection has to take into account the significance of train running interval on the thermal insulation length.

The unloading tests on rock samples under different confining pressures were carried out on the system MTS815 to study the deformation and energy characteristics of quartz mica schist with horizontal and vertical foliation respectively. The volume deformation coefficient，the energy ratio，the energy change rate and the energy stress increment ratio were analyzed to investigate the mechanism of energy evolution and deformation failure characteristics of quartz mica schist under the unloading of high confining pressure. The results show that both the radial deformation capacity and the values of characteristic stresses of the sample with the horizontal foliation are higher than those with the vertical foliation. The confining pressure has the obvious influences on the energy evolution of both type of samples. The pre-peak energy stress increment ratios of both groups increase with the initial confining pressure，however the post-peak energy stress increment ratios are almost unaffected by the initial confining pressure.

The mechanical properties of tailings are affected by the silt content，but so far，studies related to the influence mechanism of silt content on the mechanical properties are not much. This paper presents the investigation on the effects of silt content on the mechanical property of tailings and its mesoscopic mechanism. The microscopic observation，the triaxial test and the discrete element simulation were performed to study the microscopic characteristics of sand and silt. The critical silt content is analyzed based on the results of the experiment. Finally，we proposed a mesoscopic mechanism of silt content effect. The silt and sand particles are different in size distribution，angularity and surface topography. The tiny particles(＜30 ?m) have the unique microscopic features. The sandy tailing is transformed into the silty tailing with the increase of silt content，and the critical content is 30%–50%. It is theoretically proved that the smaller of silt particle size and the elastic modulus are，the bigger the deformation of soil is. Mesoscopically，the increase of salt content weakens the original force chain，thus resulting in the silt content effect.

A shaking table experiment was conducted on a shield-enlarge-dig type structure in liquefiable ground subjected to the near and far field earthquakes respectively. The lateral deformation，the pore pressure ratio，the earth pressure of soil foundation，the accelerations of soil and structure and the strains of structure of subway station were analyzed. The results showed that liquefiable foundation experienced two physical process in earthquake，the loose sand compacted firstly and then moved upwardly. There were phenomena of sand erupting and water oozing in large area after the high intensity earthquake. The shear deformation occurred in the lateral side of the soil and the peak displacements swing left and right asymmetrically. The acceleration amplification factor of soil foundation increased gradually from the bottom to the surface when the small earthquake(peak acceleration was 0.1 g and 0.2 g) was input while it showed an increasing trend when a moderate or strong earthquake was input from the shaking table. A notable phenomenon of high frequency filtering and low frequency amplification appeared in the process of seismic wave propagation from the bottom to the surface of soil. The pore water pressure experienced mainly two stages，the pore water pressure increased slowly at first， rose sharply then at the second stage. The existence of the underground structure has an inhibitory effect on the growth of the pore water pressure of foundation. The earth pressure increased and the structure itself in the elastic state entered into the plastic state gradually with the increase of input vibration intensity. The difference between the upper and lower ground pressures of the underground structure was the intrinsic factor that caused the model structure to generate an upward movement. The earthquake damage of the underground subway station of shield-enlarge-dig type in liquefiable ground experienced three stages：firstly，a shear failure occurred on the column and a damage on the opening position and spandrel of the tunnel；secondly，the connection parts of the side wall and roof had the tensile damage；finally，the underground structure collapsed.

To investigate the mechanical response of soil rock mixtures(SRM) with the oversized blocks，large-scale triaxial shear consolidated undrained(CU) tests under different confining pressures were conducted on the unconventional sample of soil rock mixtures with the volumetric block proportions(VBP) of 25%，35% respectively. The results showed that the volumetric change was still observed under the condition of undrained tests for the soil rock mixtures with the oversized blocks. The volumetric strain of soil rock mixtures with the volumetric block proportion of 35% showed the characteristics of shear contraction at the initial stage，the shear dilatation，the secondary shear contraction，and the shear dilatation once again at the higher confining pressures. The curves of the deviator stress against the axial strain are smooth under the volumetric block proportion of 25%. However the curves of the deviator stress against the axial strain have the zigzag shape under the volumetric block proportion of 35%. The jump phenomena of the stress，volumetric strain and pore water pressure were exhibited.

The adjacent tunnel is influenced by pile foundation obviously due to the additional load，particularly in the area with loess layer of great thickness which is sensitive to water content. A serious of tests with the modified centrifuge testing equipment were conducted to systematically investigate the influence of the pile foundation to the adjacent tunnel. The influence factors considered in the tests are the pile foundation load，the pile-tunnel distance and the basement immersion depth. The soil around the pile was found to reduce the load-transfer effect，which led to the lining stress redistribution. The bigger the pile load，the more obvious the reduction effect. The bearing ability of the basement was reduced due to the water immersion，which increased the load-transfer between the pile and tunnel. The influence of pile to tunnel was decreased with the increasing of pile-tunnel distance. The bending moment of tunnel was evenly distributed when the pile load was small. The tunnel was distort with the pile load was bigger and was distort more as the pile load increased. The effect was obvious when the pile-tunnel distance was short. When the immersion depth in basement was small，the influence of pile to tunnel was weak due to the load-transfer effect，but the influence was more and more obvious with the increasing of immersion depth in basement. When the ratios of pile-tunnel distance to diameter of tunnel was 1，the vertical displacement reached 16.7 mm，the horizontal displacement reached 3.2 mm under the pile load increasing，and both reduced with the increasing of pile-tunnel distance. The tunnel displacement reduced with the decreasing of immersion depth in basement. The basement immersion affected mainly the vertical displacement. The effect of basement immersion to tunnel was smaller than pile-tunnel distance and pile load.

The pile-soil stress ratio is an important indicator which reflects the characteristic of composite foundation with rigid pile-net. The pile-soil stress ratio of the composite foundation with rigid pile-net under the embankment loads was studied based on the load transfer characteristics. The reinforced area was considered as a whole body according to the stress and displacement continuity condition of cushion-piles-soil. The stress and deformation of reinforced cushion were simulated with the large deflection theory of thin plate. The real boundary conditions of the reinforced cushion were considered. The pile-soil stress ratio was solved with the assumption that the four corners were simple supported and the rest were free. The method for calculating the pile-soil stress ratio under normal conditions considering the effect of pile-soil interaction was deduced through the principle of energy. The method was validated through the indoor full scale tests. The influences of the modulus of mattress layer，pile spacing，soil bed coefficient and pile diameter on pile-soil stress ratio were systematically analyzed. The analytical solutions agree with the measured data.

Static penetration experiments is an effective method for rapid measuring the compactness of soil-rock mixed subgrade. However，the testing principle need to be further studied. In this paper，a method of stress analysis suitable for the granular material of soil-rock mixed subgrade is established by assuming the stresses transmitted downward with the shape of cone in the soil-rock mixture based on the stress transmission mechanism of granular material. The deformation modulus，Poisson?s ratio and porosity varied with the deformation of subgrade is determined on the basis of the porous media mechanics. A force-settlement relationship of soil-rock mixed subgrade，i.e. the P-s curve，is established based on the layer summation method. On the basis of the P-s curves obtained with the static penetration experiments，the initial porosity is obtained with the method of back analysis using an adaptive algorithm. The method for rapid measuring the compactness of soil-rock mixed subgrade is thus established. The accuracy of this method meets the engineering requirement without the complicated calibration experiments. The results of proposed method were compared with the results from tests and existing method and proved that this method was reasonable and feasible.

Seismic damages of embankment occurred widely in strong earthquakes. It is very important to carry out the probability risk assessment and to put forward a reasonable risk management method to improve the anti-seismic capacity of highway and the capacity of regional damage prevention and mitigation. The seismic damage levels of embankment were classified and the seismic damage parameters were selected. The relationship between the seismic damage levels and seismic damage parameters was established. The embankment at K1125+470 of the expressway of Xi?an to Baoji was studied with the seismic hazard assessment to highway based on CPSHA，the seismic fragility assessment on embankment based on IDA and PSDA，and the seismic probability risk assessment on embankment based on the hazard curve. The acceptable risk and the risk management method for embankment seismic damage were put forward. The positive effect of the retaining wall on the anti-seismic performance was verified. The seismic hazard assessment results of Xi'an－Baoji segment in Lianyungang－Huoerguosi expressway is higher than that of the fourth generation seismic zoning map，which is consistent with the reality of seismic activity in Weihe fault basin. When PGA(PGA is peak ground acceleration) reaches 0.6 g，the probability exceeding the severe damage is 65.910%，when PGA reaches 0.8 g，the probability exceeding the severe damage is 99.995%，indicating that the embankment is prone to seismic damage. The risk probability of exceeding the severe damage in the next 50 years is 36.46% and the probability of mainly intact and minor damage is 28.49%. The probability risk being 40% exceeding the severe damage in the next 50 years is regarded as the acceptable. The risk management method is suitable for the anti-seismic design of new embankments and anti-seismic strengthening of existing embankments. In the next 50 years，the probability risk exceeding the severe damage of the embankment with a retaining wall is 15.29% lower than the one without a retaining wall. The probability of mainly intact and minor damage is 15.62% higher than the one without a retaining wall.