The water inrush hazards have become one of the bottleneck problems that constrain the construction of underground engineering such as tunnels. The advanced detection of the water-bearing geological structures especially estimation of the water volume in tunnel construction period has become an important scientific and engineering problem to be studied and solved urgently. For the above problems，the solving method with the induced polarization(IP) method as the guide is proposed. The advanced geological prediction with IP method in tunnel faces with a lot of new problems to be studied and solved urgently in contrast with shallow exploration. The special IP instrument for tunnel advanced detection is developed. The thought for solving the problem of water-body location with apparent resistivity is presented；and the three-dimensional(3D) tomography method of water-bearing structures advanced detection based on 3D resistivity inversion method and its computation scheme is proposed. The basic problems of tunnel advanced detection are solved(e.g. solution of point source field in 3D whole space，3D measurement mode，recognition and removal of the measurement disturbance，inversion target region). The feasibility and effectiveness of 3D tomography for water-bearing structures has been proved by massive inversion examples. For the problem of water volume estimation，the method based on half-decay time difference of two-current induced polarization is put forward. It is found that the relation between difference of half-decay time and water volume is linear positive correlation by physical model test. And this linear positive correlation lays a solid foundation for water volume prediction of water-bearing structures in practical engineering. In the end，advanced detection technical system with IP method for tunnel water-bearing geological structures is formed. And this technical system is introduced into geological forecast work in tunnel engineering. The prediction results are basically identical with the practical excavation results. Practical application demonstrates that the problem of advanced detection for tunnel water-bearing structures especially the water volume estimation is solved effectively with prediction technique of IP method；and it has good application prospect and popularization value which extends the function of advanced geological prediction technique.

In the southwest of China，many large-scale underground power stations were built in the high mountain zone with high in-situ stress. If the rock mass behaved brittle，splitting cracks would happen on the high side wall of underground caverns. The authors tried to study this kind of phenomena adopting laboratory tests，in-situ monitoring and theoretical analysis. Firstly，laboratory tests were carried out based on brittle rock-like samples，in which loading was applied in three directions at the beginning and was removed in one direction to simulate the excavation process. The splitting phenomena appeared in the tests. Then，a criterion presented before was applied to predicting the splitting failure depth of rock mass. In-situ monitoring aiming at abserving the splitting zone and displacement of rock mass was conducted，in which sliding micrometer and electric resistivity method were adopted. Afterwards，feedback analysis was carried out combining the excavation process of caverns. The latest established splitting analysis method considering energy dissipation was adopted to predict the displacement and splitting zone of rock mass caused by the following excavation and achieved some good results.

It is of significance to research the thermo-hydro-mechanical characteristics of rock mass under the condition of low temperature and freeze-thaw cycles for engineering construction in cold regions. The four aspects：physico-mechanical properties of rock，temperatures，seepage characteristics and thermo-hydro- mechanical coupling characteristics under the condition of low temperature and freeze-thaw cycles were reviewed；and combining with the characteristics of tunnel in cold regions，a new idea to research the frost heave of surrounding rock and its insulation measure were put forward；firstly，based on field monitoring，a large number of freeze-thaw tests，uniaxial compression tests and triaxial compression tests，the thermo-hydro-mechanical parameters，such as coefficient of thermal conductivity should be obtained exactly；and then a proper coupled thermo-hydraulic model for low temperature rock including phase change should be established；after this，a damage factor is proposed to consider the freeze-thaw effect in rock and the thermo-hydro-mechano-damage coupled model considering the effect of volumetric strain on temperature and seepage field of surrounding rock and the effect of temperature gradient，seepage pressure and frost heave pressure on mechanical field for tunnel in cold region can be established to study the frost heave of surrounding rock；meanwhile，a high-performance foamed concrete is designed as an insulation material used in tunnel，which has the characteristics of lightweight，insulation，cold-proof，crack resistance and aseismic.

The generation and evolution of zonal disintegration are analyzed by means of numerical simulation. Based on maximum tensile stress criterion and strain energy density theory，the element failure criteria have been developed in terms of mesoscopic level. Then the elastic damage mechanics is considered to simulate the failure behavior of rock. In the specific numerical modeling process，the released energy caused by the excavation of underground workings must be large enough to bring about dynamic phenomenon of the surrounding rock. In other words，the excavation process can be considered as dynamic process. Based on the above concepts，the zonal disintegration code has been developed by the FISH of FLAC3D. Then it was used to determine the failure pattern of the rock mass around the deep roadways and the quantity and width of the zonal disintegration also have been obtained. The results of numerical simulation are in good agreement with the in-situ monitoring results.

Water inrush and mud gushing are the typical common geologic hazards for the karst tunnel construction. Based on risk evaluation model of water inrush，management system of construction permission mechanism can be established to reduce the economic loss and water inrush risk. The major factors are summed up and selected as the impact factor of fuzzy analytic hierarchy process(FAHP) by collecting and collating information of water inrush examples of karst tunnels in recent 50 years，the membership function is proposed between the factors and the probability of occurrence of water inrush and its volume，and a FAHP model of risk evaluation for water inrush is established by a comprehensive assigning method which is adopted to determine the weight of evaluation indices；and water inrush risk can be evaluated for the three different stages of tunnel construction. Firstly，based on the preliminary evaluation for environment of dangerous source at the prospecting stage，the risk factors effect and construction of risk reduction can be determinated. Secondly，pre-evaluation of water inrush for environment of dangerous and risk factors can be done in order to prove the effectiveness of construction organization at the design stage. At last，based on distribution of the pre-evaluation results，risk grade can be modified by tracing the hydrogeology，mechanical and geophysical information of exposed rock during the excavation process；and risk control criterion and countermeasures for different excavated sections can be determined by identifying the environment of dangerous source and risk factors for next excavated section；and management system of construction risk can be established in order to get the accurate，effective and real-time risk control of water inrush. The risk management system of water inrush has been proved that the evaluation result is accurate and reliable by its application to three typical karst tunnel of Sanxia highway，which can be further used for other underground projects.

The theory of thermal diffusion in surrounding rocks affected by mining around the water-bearing structure is studied. The new style advanced model test device and similar material of typical hydro-mechanical coupling is used and the monitoring system of grating temperature and displacement is improved. The coal mining around the water-bearing structure is simulated by tests. The variation laws of seepage and temperature fields induced by deformation of overburden rock during mining are analyzed. There is obvious abnormal temperature feature in the intact rock mass around the water-hearing structure before mining. The temperature of rock mass reduces gradually with the mining. Temperature response feature of water inrush is obvious in layered rock mass upper the gob. The temperature fitting curve of rock mass is concluded with the data of the model test. It provides the theoretical foundation for the forecasting water with rock mass temperature method.

The creep behaviour is an important parameter to estimate the feasibility and safety of underground gas storage in rock salt caverns. The paper mainly presents an experimental study about the creep behaviour of Jintan rock salt by means of the digital image correlation(DIC) techniques，which not only can give a full-field strain，but also can follow the evolution of the microstructure of the material. The two symmetrical surfaces of the cubic samples have been investigated during the creep test by two digital cameras. The results show that the strain rate in stable creep is about 10－9 s－1 at the axial stress of 11 MPa. The dependence of the strain rate upon the stress，time-dependent damage and the relation between this dependence and the microstructure are discussed. 

In order to study the process of construction mechanics under different excavation methods，a large-scale model test system is developed. Its maximum external dimensions is 5.2 m wide，4.5 m high，and 2.7 m thick. It has the features of stressing definite，reasonable structure. It can be disassembled and combined at will. Automatic hydraulic control system has the features of high pressure，long pressure holding time，steady loading and loading in gradient，etc. Various 3D and 2D geomechanical model tests of underground engineering can be satisfied. On the basis of the existing geomechanics similar material，a material ratio was attained for soft rock by a large number of different material ratios with their mechanical parameters being tested. Large scale 3D geomechanical model test about construction process of railway tunnel was developed. The changing mechanical process was simulated truthfully. Test results show that the test system is stable and reliable，and can be widely used for geomechanical model test in other underground engineering；research methods，techniques and the results make certain guiding significance to the practical engineering.

The moving least square meshless method and the couple stress theory were combined together. Discrete model of moving least square meshless method was derived based on couple stress theory. First，stress concentration of the circular hole was studied under couple stress theory. The basic parameters of the method were determined；and the key technology of the algorithm application was also solved. On this basis，as for the plane stress problems，stress intensity factor and normal stress near crack tip of the central crack-I，stress intensity factor and the maximum shear stress of single and two boundary crack-I，and initial rupture of oblique central crack were studied with different characteristic lengths. Meanwhile，influence of shear force and fracture pressure on scale effect were presented. The results show that the couple stress has a significant influence on shear stress at crack-I tip，little influence on normal stress at crack-I tip. The couple stress has a significant influence on oblique crack bending propagation for plane stress problem. For oblique crack，the crack propagation angles，steps and loads show remarkable scale effect. The horizontal shear may intensify the scale effect. The fracture pressure has little influence on scale effect.

Grouting pressure-grouting flow-grouting time(P-Q-t) control method in grouting entire process，geophysical method，check drilling method and digital camera method from macro to micro had been applied in testing in grouting effect of water filling fault F4–4 in Qingdao Kiaochow Bay subsea tunnel. P-Q-t control method in grouting entire process in which the entire process of grouting P-Q-t control act，grouting pressure in order to limit within 3–4 MPa，when the speed is less than 5 L/min grouting over 20 min，the grouting was ended；the TSP is used to check the surrounding rock after grouting. The results indicate that the integrity of surrounding rock has improved；and its deformation modulus has improved 19.1%；and its density has improved 3.6%；and its Poisson?s ratio has reduced 7.1%；and the VP has improved 0.8%；and the ratio of longitudinal wave velocity of transverse wave velocity VP/VS has reduced 7.1%. The drilling inspection holes amount was 5%–10% of grouting holes. When the single-hole out of water was less than 0.15 L/min，it reached grouting requirements，then it meets the excavation allowed out of water standard. The digital camera method generated three- dimensional virtual cores，then calculated the fracture gap filling paste filling pulse width and the occurrence. It is indicated that the water-filled fissure filling compact. All of above four kinds of test methods determined that the surrounding rock level of water filling fault after grouting has improved from grade V to grade IV. The results show that the grouting effect is good；and it achieved the purpose of reinforcement of the grouting sealing. The comprehensive check method is an effective method of grouting. The above method has some referential and guidance significance to similar projects.

The design of reasonable flat ratios for flat and large span shallow tunnel has very important effect on cost saving and expense reduction for ventilation and lighting. Therefore，optimizing the flat ratios of shallow large-span tunnel is the key problem faced by the tunnel design and construction. Firstly，program with the standard design language Python of general-purpose finite element software ABAQUS to achieve parametric design for the different flat ratios of large-span Panlong tunnel in shallow broken rock mass planned to be constructed in Qingyuan City. Then，the stability and deformation failure of tunnel structure under 5 kinds of flat ratios are researched. Target values of excavation area，horizontal convergence，ground surface settlement，vault subsidence，etc. which affect the stability of flat tunnels，are optimized using the analytic hierarchy process(AHP) and determining their weight vectors. Finally，the optimal flat ratio under supported project is put forward. The results and method of this paper provide reference for the section optimization design of tunnel engineering in equivalent conditions.

By analyzing the project example of Jijiapo tunnel?s lining fracturing，studies were done on the karst developing characteristics of the tunnel district，and a kind of water bearing structures，steeply inclined and filling type of karst fissure，was probed. Its configuration，filling?s characteristics and disaster-causing mechanisms were studied. Measurements，as fissure-blocking，perinous grouting，discharge of water and release of pressure，substitution of structures，as well as information grouting assessment methods，were taken to govern water inrush-lining fracturing in tunnels. Steeply inclined and filling type of karst fissure-water bearing structure occurred in a steeply inclined angle of fissure，easily accumulate water and form a high water pressure in its fissure space. In addition，sediments easily accumulate at the bottom for its slow migration in a fissure. Because of dead weight stress and high water pressure compaction，the filling medium changes to poorly permeable，hard or semi-hard sedimentation and cementation. It is often neglected when excavated and revealed for there is no or a litter of water inflow. However，after a period of time?s excavation，the filling medium of the fissure is washed out gradually by water and will finally lead to piping，soil flow or entirely extrusion out；and then import underground，cavern or surface water into the tunnel，causing disasters of lining fracturing，water inrush and so on. Research results are not only used for the controlling of water inrush in Jijiapo Tunnel，but also have strong reference value for avoiding and controlling similar disasters.

Single specimen is used for rheological test method under multistep loading，which avoids the discrete affection of specimen for rheological deformation. But the deformation of the later loading contains the creep deformation induced by the former loading of all levels by this method，which always makes people confused. The memory effect of loading history for the rheological media is analyzed detailedly；and the concrete steps and mathematical basis of the data processing are proposed. Based on the triaxial rheological test results of diabase in dam foundation of Dagangshan hydropower station，the typical character of rheological curves is analyzed. According to loading creep test curves under different stress levels，by connecting the instantaneous elasticity Hooke body，visco-elastoplastic Schiffman body and nonlinear viscoplastic body in series，a new nonlinear visco-elastoplastic rheological model of rock is proposed. Through introducing the nonlinear viscoplastic component，this rheological model can describe the transient creep stage，steady-state creep stage and tertiary creep stage. Three-dimensional rheological and creep equations under constant stress are deduced. On the basis of complete creep curves gained by rheology equipment，the rheological parameters are inversed. The comparison between nonlinear rheological model and experimental curves shows that two curves accord well with each other，and the proposed nonlinear visco-elastoplastic rheological model is available and reasonable.

In the construction of underground engineering， the key-hole grouting method is first proposed in the treatment of high pressure water gushing problems of fractured rock mass. A key-hole optimization method of multilevel factors has been studied by analytic hierarchy process(AHP). In practical engineering applications，grouting holes have been optimal designed by conclusions of geological analysis and physical exploration. Then the key-hole optimization method is used to select holes. The grouting parameters have been designed referencing conclusions of interconnection test. Finally，a good plugging effect has been achieved by grouting. The key-hole grouting method has good popularized value to similar projects.

Tight gas refers to natural gas produced from reservoirs that have very low porosities(＜10%) and permeabilities(＜0.1 mD). Physical fracturing of these formations could enhance the overall formation permeability and improve tight gas extraction. One of the outstanding issues in rock fracturing is to determine the magnitude of applied effective stress. The general effective stress law is defined as： ，where   and   are total confining stress and fluid pore pressures，respectively，and  is Biot?s coefficient. For soils，the Biot?s coefficient equals one，but for rocks，especially fluid-saturated rocks，the Biot?s coefficient is not one. It is concluded that the Biot?s coefficient   is not only a particular material property，but also markedly sensitive to the magnitude of applied confining stress and pore pressure. The main objective of this study is to experimentally determine the Biot?s coefficient for permeability of Nikanassin sandstone. A series of permeability measurements were conducted on Nikanassin sandstone core samples from the Lick Creek region in British Columbia under various combinations of confining stress and pore pressures. The results show：(1) Tight gas reservoir sandstone has a very low permeability with an order of magnitude of 0.01–0.001 mD and there is an exponentional relation between permeability and pore pressure under the same confining pressure；(2) Biot?s coefficient is increasing with the permeability；(3) the average values of the two sandstone samples are 0.509 and 0.612，respectively.

Compared to the normal road or railway tunnels，metro passed through the stratum over the road，so that the metro advanced prediction(mainly geophysical class prediction) implementation can be divided into two parts：prediction inside and outside the tunnel. However，due to shallow depth of the metro and many factors of interference，it?s need to use the comprehensive advanced prediction. By analyzing the metro characters under the karst geological conditions，using the advantages of ground penetrating radar(GPR) and resistivity tomography，a comprehensive prediction method is proposed to carry out GPR forecasts inside and carry out the forecasts of the combination of resistivity tomography and GPR method outside；then through an engineering application，a detailed analysis of the implementation of comprehensive and comprehensive forecasting methods is made to prove that the comprehensive prediction method is effective for metro advanced prediction under the conditions of karst geology.

It is a technical difficulty to control the deformation and the stress condition of the structure of large-scale shield shaft in over-river shield tunnel project. This case study how to deal with the excavation of Jiangbei shield shaft of Weisan Road over-river tunnel at Nanjing City. Use four-factor at three-level orthogonal array experimental design method to proceed multifactor system analysis，studying the  effect rule of deformation and stress of the whole support structure caused by the change of the thickness of ring beams，retaining wall，lining wall and bracings. The interaction relationships between each support component are obtained and analyzed；and through the quantification analysis of the total cost，a design scheme of the minimum total material cost is proposed which has been conditional on the security of the whole structure. This study indicates that：using orthogonal experimental design method to decide the reasonable support parameters of the shield shaft can minimize the calculation，obtain the optimal combination of the support parameters with the confirmation of stability，and achieve the best technical and economical result.

Splitting failure happened frequently in the brittle surrounding rock mass of underground powerhouse cavern groups in southwest of China while excavation was performed. This kind of special engineering phenomenon has obtained become more and more attentions now. Adopting the linear slippage crack groups splitting model and applying fracture mechanics，energy analysis and crack propagation，the splitting criterion of cavern rock mass and displacement forecasting method reflecting splitting opening displacement was derived. Meanwhile，the effect of intrinsic cracks propagating into macroscopical splitting cracks parallel to the side wall of caverns approximately was considered. Moreover，the forecasting method was applied to the Jinping I hydropower station underground caverns engineering in China；the splitting failure zone and forecasting displacement were coincide with the monitoring data. The new forecasting displacement method could benefit the construction of similar underground caverns.

By the laboratory experiments，main performance parameters and characteristics under dynamic water condition of a new type grouting material are studied. The initial/final setting time of the grouting material under different water-cement ratios，different volume ratios of slurry to admixture and different temperatures are tested. The stone rate(3 h) of material is tested. Based on the material and process requirements of dynamic water grouting engineering，slurry retention rate with different water velocities and the pumpability after initial setting time are tested. According to the performance parameters of grouting material and the field condition，the optimum mixture ratio of the new grouting material is determined. The operation technology of dynamic water grouting material is studied.

The stress-strain curves of rocks are composed of two parts，which are pre-peak region and post-peak region. In the pre-peak region of stress-strain curve，rocks are usually regarded as elastomer. At this stage，the constitutive relationship is linearly elastic. However，in the post-peak region，the curve could not be determined by classical theory because the fracture morphology and the stress drop of the rocks are hard to describe. Thus，the post-peak modulus is the key of the mechanical behavior research. Based on Mohr-Coulomb criterion，the paper uses internal friction angle as intermediate variable to propose post-peak elastic modulus. The nonlinear post-peak stress-strain relationship of rock is established. In numerical cases，the stress-strain curves under different confining pressures are obtained and they agree well with the test data. It is concluded that the fitting curve model proposed by this paper is reasonable and the model could describe the post-peak mechanical behavior of marbles under various confining pressures preferably.

Recently，underwater tunnels have progressed vigorously in China. Therefore it is necessary to research this type of tunnel using the analogous material test. The test bench composed of high-strength PVC board and structural steel was manufactured. Optical fiber monitoring system and collection device of water seepage were exploited. The new type of solid-fluid coupling analogous material was improved. Then the fluid-solid coupling model test was performed for the Kiaochow Bay Subsea Tunnel. Water inflow and multiple information like the displacement，stress and seepage pressure of key points were recorded in the test process. In order to verify each other，numerical simulation which was similar to the physical test was made using fast Lagrangian analysis of continua in 3 dimensions(FLAC3D). The test results are credible because that the spatial distributions of multiple information got from the representative working condition accord with the general rule. Compared with the numerical simulation，physical test can take influence factors such as the excavation disturbances，water level fluctuations and wall-rock weakness due to seawater immersion into account；so that the results obtained from physical test approach the actual engineering conditions more.

Laboratory tests on the large post-liquefaction deformation of saturated Nanjing fine sand were performed by using a hollow cylinder apparatus. The stress-strain relationship and the characteristics of excess pore water pressure after liquefaction were studied. It is found that the relationship between deviatoric stress and axial strain presented a sigmoid curve；and there is a good linearity relationship between normalized pore water pressure and deviatoric stress. On this basis，a constitutive model of stress-strain relationship and a dissipation model of excess pore water pressure are established. It is found that the results predicted by the two models are in good agreement with the experimental data. The influence of relative densities and confining pressure on the characteristics of liquefied soil are studied. The results show that the relative densities and initial effective confining pressure all have an important influence on the stress-strain relationship of liquefied saturated sand. However，the dissipation model of excess pore water pressure after liquefaction is only affected by the confining pressure.

According to the characteristics of installation about the seismic piezocone penetration tests(SCPTU) penetrometer and the pile，a theoretical relationship between time-effect of shaft bearing capacity of single pile and the data measured from SCPTU is developed，which can be used to predict the variation of shaft bearing capacity of a jacked-in pile with time in saturated soft clay. Different from the traditional way，the effect of different stiffness index and consolidation coefficient on the consolidation process in varied clays and highly stratified deposits are considered in the new theoretical solution. Besides，the ration of the solution is verified by the single pile loading tests in different time period after installation.

By conducting dynamic centrifuge model tests on the clay-pile-raft system，this paper investigated that a kind of dynamic interaction non-coincidence between soil and pile-raft foundation. This suggested that soil motion can not be representative of foundation motion，and that adopting free field soil seismic parameters directly as foundation parameters in traditional building aseismic design is unreasonable；differences on the acceleration time histories，response spectra，as well as resonance period between soil and pile-raft foundation are very obvious and can not be neglected in engineering aseismic design. The effects of modulus reduction and stiffness degradation are manifested as an increase in the resonance periods of the clay layers with the level of shaking and with successive earthquakes，while this is not the case for the pile-raft foundation since its resonance period is hardly affected by earthquake loadings. Furthermore，raft period is always lower than corresponding clay period and period of far field clay is lower than that of near field clay because of remolding softening effect under the same condition，and pile-raft dynamic behavior is hardly affected by the stiffness degradation of surrounding clay.

Through 7 clayey sand consolidation tests of suction and net mean stress both changing，the variation laws of 7 stress paths were studied in the p-s-v，p-s- ，p-s- and p-s-w spaces with the variation between suction and net mean stress included angle ?. Where p is net mean stress；s is suction；v is specific volume；  is volume deformation；  is volume deformation in water phase；w is moisture content；? is angle. The test results indicate that net mean stress is a very important factors to the volume deformation；the suction is the first conditions to the moisture changing. The yielding point locus is studied and given a unifying parabola expression in the p-s plane. Finally，using the predecessor test data forecasted yielding point locus laws in the p-s plane that proved the unifying parabola expression is credible.

Two slope models with the geometric scale of 1∶8 were designed and two large-scale shaking table model tests were performed to study the seismic displacement modes，its characteristics and aseismic behavior of four retaining structures including gravity retaining wall，sheet-pile retaing wall，anchor lattice frame structure and prestressing anchor lattice frame under seismic loading and in three excitation directions including X-，Z-，and XZ- direction respectively. The results show that：(1) In X direction or XZ-direction excitation，the seismic permanent displacements of gravity retaining wall and sheet-pile retaining wall are negligible at the peak excitaion acceleration AXmax≤0.4 g. In Z-direction excitation，the seismic permanent displacements of sheet-pile retaining wall and prestressing anchor lattice frame are also negligible. (2) In X-direction excitation and at AXmax＞0.4 g，the seismic displacement mode of gravity retaining wall is the slide-based coupling of the sliding to filling soil mass and the rotating inward about base，and the seismic displacement mode of sheet-pile retaining wall is the sliding to filling soil mass. In Z-direction excitation and at the peak excitation acceleration AZmax＞0.267 g，the seismic displacement mode of gravity retaining wall is the coupling of the sliding to filling soil mass and the rotating inward about base. In XZ- direction excitation and at AXmax＞0.4 g，and AZmax＞0.267 g，the seismic displacement mode of gravity retaining wall is the rotation-based coupling of the sliding to filling soil mass and the rotating outward about base，and the seismic displacement mode of sheet-pile retaining wall is the slide-based coupling of the sliding from filling soil mass and the rotating outward about base. (3) In X- or XZ- direction excitation，the seismic displacement mode of prestressing anchor lattice frame is the translation of outward and lower of the slope and same as that of anchor lattice frame structure. In Z- direction excitation and at AZmax＞0.267 g，the seismic displacement mode of the translation of outward and upper of the slope of anchor lattice frame structure is gradually transformed into the translation of inward and upper of the slope. (4) The aseismic performance of sheet-pile retaining wall is better than that of gravity retaining wall at X- or Z- direction excitation，but poor than that of gravity retaining wall in XZ- direction excitation. The aseismic performance of prestressing anchor lattice frame is better than that of anchor lattice frame structure at X-，Z-，and XZ- directions excitation.