The critical bifurcation orientation and its corresponding hardening modulus for rock-like geomaterials are derived considering the effect of stiffness degradation and volumetric dilatancy under the assumption of isotropic damage. The dependency of the localized orientation on damage degree and initial Poisson’s ratio of rock is examined and the bifurcation behavior of uniaxial tension sample under plane-stress condition is compared with that under plane-strain condition. It is shown that the localization orientation angle intimately depends on both initial Poisson’s ratio and damage degree for the rock sample under uniaxial tension condition. As the initial Poisson’s ratio or damage degree increases, the orientation angle of the plane on which localization tends to be initiated gets to increase. At the same time, the localization orientation angle of rock sample under plane-stress condition is lower than that under plane-strain condition.

The shear deformation of soil can not be considered sufficiently by Cam-clay model and the actual deformation characteristic of soil material can not be reflected in engineering projects. In the paper this disadvantage of Cam-clay model is theoretically analyzed firstly; and the idea of adopting different proportional coefficients to strain components induced respectively by shear stress and volume stress is proposed; then based on the idea and using the shear test results performed by Nanjing Hydraulic Research Institute, the Cam-clay model is modified; and the concrete stress-strain formulas of modified Cam-clay model are presented also. The comparison of the computed results of correlation between shear stress and axial strain by the improved model and the Cam-clay model shows that the shear deformation can be considered effectively in improved Cam-clay model. Besides, the four material parameters in modified model are easy to be measured.

A new method was presented to evaluate the stability of a slope with strain-softening behavior through introducing a simplified strain compatibility equation of the slope and expanding the concept of Swedish slice method. The formula of the simplified method were derived and their algorithm was programmed into a software. The method was confirmed to be reliable and efficient by the practical applications. The slice number and assumed initial slide surface have little effect on the stability analysis accuracy. The stability factors and corresponding critical surfaces of slopes with different strain-softening behaviors were analyzed with the presented method. The results show that the factor of stability of a strain-softening slope depends not only on the strength parameters but also on the shear stress-strain relationship of soil, which is less than the one corresponding to peak strength and more than the one corresponding to residual strength by the limit equilibrium method.

Considering especially the influence of the thermal water diffusivity and the isothermal vapor diffusivity on the continuity of water and the energy balance, the author improves further the established control equations for analyzing coupled thermo- hydro-mechanical phenomena in saturated-unsaturated porous media; and makes the numerical simulation for the coupled thermo- hydro-mechanical processes in near field of a conceptual nuclear waste repository by using a FEM code developed by the author and the experiment data; and investigates the changes and distributions of temperature, saturation, pore pressures and principal stresses in the buffer and the rockmass. The part results obtained are compared with the computation data of foreign similar code; and it is shown that the regulations of both results have certain identity qualitatively and quantitatively. and some conclusions are drawn.

Gaussian equation suggested by professor Peck in 1969 is one of the most popular-used methods to predict the soft ground movement induced by shallow tunneling work. The application of this method in China should be carefully verified and evaluated since it was suggested based on case history studies. Because of the lack of the well-compiled measured data in China, there is no clear conclusion on the adaptability of the Gaussian equation to predict the ground movement induced by the metro tunneling until now. Based on the collection of the published case history analysis, including more than 30 sets of measured data from eight areas in China, the accuracy of the Gaussian equation applied to predict the ground settlement is discussed and evaluated in detail. some typical key parameters are also suggested to the designers.

The formation and basic characteristics of sand-sliding slope composed of granular clasts are researched based on spot investigation and model tests. First, the effect of sand source region, sliding region and accumulation region in the development and evolution of this kind of slopes are discussed respectively. Then, the structural characteristics of loose matters which form the slopes are discussed. The influential factors and their significance analysis of natural repose angle of loose matters are concerned and a linear regression equation is derived to determine the angle. The stability and its identification index are analysed at the end.

Evaporation effect on the suction in the unsaturated soils is analyzed by solving the equations of isothermal flow and coupled heat-moisture anisothermal flow with various calculated models of evaporation. The influences of various climatic parameters and soil properties on the calculation of evaporation are also discussed. It is shown that the behavior of suction in the unsaturated soil can be perfectly modeled by the equation of coupled heat-moisture anisothermal flow with the formulation of considering actual evaporation and commonly-used methods by solving isothermal flow with the boundary of potential evaporation evidently overestimate the evaporation magnitude in the soil surface and the decreasing magnitude of suction. The major governing factor for the evaporation of soil surface is outer climatic condition where solar net radiation and wind velocity are the most contribution, while the internal parameters of soil property play a less role in the estimation of evaporation.

This paper puts forward an overall new theory of the idiosyncratic verge of silt sedimentation for the Yellow River. It emphasizes on the research of the comparison of the important information recorded in the sedimentation of natural events on the idiosyncratic verge in the process of evolution of the life of the Yellow River. It can be concluded from the comparison that the development, evolution and water transmit laws of the river course, which will serve the current river training and the maintenance of the health life of the river.

Shield tunneling causes movements of the soil around the tunnel, so estimating potential soil movement is very important to control soil movement amount and protect existed construction foundation and underground pipelines. Soil displacements are induced by ground loss and are affected greatly by grouting amount. According to the regularities of distribution of ground loss and grouting amount, the paper initiates spatial analysis of soil displacements and stresses during shield tunneling by using image theory. Comparing with the observed results of Tianjin metro project, it is identified to be dependable.

The concrete wall would crack under design load, which is the fact and one of working principles in steel lined reinforced concrete penstocks. In order to release the contradiction between cracking and limiting crack width, model tests and FEM are adopted to study on some measures of crack control, and calculation method of crack width. The results show that cracking width would decrease when using more bars and thinner lining, that cracking width would decrease slowly when reducing the thickness of concrete wall, that waterproof painting has the better properties of cementation and deformation, and can be studied on improve durability of materials by long-term tests, and that the result using the calculation method in code П-780-83 to calculate crack width, is coincident with the result of model test.

There are large numbers of brine-extracted caverns which can be reconstructed as the nature gas storage in the exploited salt mine. It can availably shorten the construction time of natural gas storage and eliminate the disadvantaged effect of brine-extracted caverns to the environment. Based on the geological data of the salt mine and the mechanical behavior of salt rock, the four brine-extracted caverns which will be reconstructed to the nature gas storages are studied by the three-dimensional numerical simulation. The stress state around the caverns and the volume convergence law of the caverns are studied under the various gas recovery velocities. The better conclusion about the optimized gas recovery velocity of natural gas storage is obtained by the research.

The axial stress and axial displacement distribution curves of the concrete core mixing single pile are researched by ANSYS software; and the differences of the single pile ultimate capacity of concrete core mixing pile between different concrete core pile length and area replacing ratio are analyzed; then the single pile ultimate capacity of concrete core mixing pile is compared with that of concrete pile. The different seismic response analyses in time domain is performed with 3-D finite element method, taking into account of the interaction among pile-soil-superstructure. The differences between composite foundation of concrete core mixing pile and pile foundation in seismic response are analyzed. Some parameters influencing the aseismic behavior of composite foundation of concrete core mixing pile are studied. The results show that the core pile shaft friction undertakes the mass of vertical load of the pile; and it is found that there are an optimum core pile length and area replacing ratio for the concrete core mixing pile. The maximum bending moment and shear force of concrete core mixing pile are greater than pile foundation’s under the same seismic response. The maximum moment of concrete core mixing pile lies in the (0.2-0.4) L; the effect degree of area replacing ratio on bending moment and shear is greater than concrete core pile length’s effect; the effect of elastic module of cement-soil is slight.

Based on the test results of sand, mechanics of internal parameters (plastic volumetric strain and plastic deviator strain) depending on stress path is explained. General equation expressing hardening parameter independent of stress path is proposed. The plastic work and the unified hardening parameters for clay and sand proposed by authors are all special examples as general equation. The combination of the unified hardening parameters and Cam-clay model, and the comparison with the test results, show that this parameter can be used to constitutive model simply and effectively.

The aseismic behavior of rigid pile composite foundation was investigated by shaking table tests with a scaling factor of 1/10. In order to better simulate the vibration of the subgrade under earthquake; and flexible wall container, a new technique, was used. In addition, vertical force was applied to the foundation and a damper was installed on the structure in order to have a better similarity in the foundation pressure and in the damping ratio. Through a number of shaking table tests, the aseismic behavior of rigid pile composite foundation and the effect of the flexible wall container were investigated. The results of the tests show that the rigid pile composite foundation has good aseismic performance; the boundary effect of model test could be reduced by the flexible wall container; the strains of the piles did not reach critical value even under quite large seismic wave input; the influence of superstructure on the deformation of piles was not negligible; and the shaking could weaken the constraint of soils to the foundation but increase the constraint to the pile heads.

Soil stress measured on buried pipe is not distributed with the figure assumed by present calculation method. Its figure has close relation with relative stiffness between pipe and soil as well as construction method. Therefore, on the basis of stress characters obtained by field measurement and model test, under condition of plain strain, through simulating interaction between pipe and soil with Vlazov Model for interaction analysis, the new method with regard to different buried conditions, different fill-in material around pipe and soil stress status caused by interaction between pipe and soil, etc. is established. A visual computer software is designed on the new method; and calculating buried pipe tool innovation is realized. By using the software, the buried pipe in Shanghai was analyzed and the validity of the method was proved by compared with site measured result.

On some occasions, multiple physical or chemical interactions between the fluids and solid skeleton in porous media may take place. Adsorption of fluids is a kind of phenomenon of these interactions. During these interactions, conversion or transfer among kinds of forms of energy take place concomitantly. In this paper, swelling of media caused by fluids in the pore is supposed to be the result of energy inversions from fluids to the media skeleton. Based on this cognition, Miao’s humidity stress field theory is proved theoretically using the first law of thermodynamics and the general method of constitutive theory. Then the applicable conditions and physical meaning of the humidity stress field theory are analyzed. It can be concluded that humidity stress field theory builds a mathematical material which is the idealization of real matter in the manner of the classic elastic theory does.

On the base of macroscopic and meso-scopic testing on cemented soil in the situation of saturated with water, a damage evolving variable is proposed corresponding with a meso-damage constitutive model established. Not only initial density of water but also initial damage of cemented soil has influence on damage evolving variable. Compared with experimental curves of cemented-soil, it is shown that the damage constitutive model has in good coincidence with the testing results. And the constitutive model can describe the damage characteristic of cemented soil saturated with water.

Strength reduction finite element method is used in road tunnel. Based on latent slip surface and safety factor, the rationality of the designed parameters of support and excavations can be judged. The result shows that the distribution of plastic zone is effected greatly by Poisson’s ratios; however, safety factor varies little with it. The higher quality of rock, the more distribution of plastic zone under limit state is got. But the failure zone is lower. Additionally, the more thickness of upper rock layer, the more distribution of plastic zone under limit state is found. Meanwhile, the safety factor decreases. The example also shows that the plastic zone of good rock quality is larger than that of poor rock quality at failure condition. So it is deserved to study about judging safety of tunnel only by its plastic zone.

During construction of the middle drift of a multi-arch tunnel, collapse accident occurred. According to the field geological and construction conditions, the numerical model is set up; and the commercial software FLAC is adopted to simulate the behaviors of the tunnel and surrounding rock. Based on the results of plastic zones in surround rocks, deformations in rock and lining, and the inner forces within rock bolts and reinforced concrete lining, the deformation of the tunnel and the causes of tunnel collapse are analyzed. The corresponding effective remedy measures are proposed; and good results are achieved.

Based on strain control consolidated undrained triaxial tests, stress-strain relationship and strength characteristic of expansive mud-stone are investigated and analyzed. The results show that the stress-strain relationship appears strain softening, and joints in mud-stone are important factor that influences strength characteristic. Different failure modes have different stress-strain relationships. Furthermore, the results also show that the peak strength, residual strength and residual strength ratio change with variation of confining stress, and development of pore pressure has three stages. By controlling shear speed ratio of triaxial test, influences of shear speed ratio on the stress-strain relationships and strength characteristic are discussed.

The excavation, the creep of soft rock and rainfall are the main reasons for the failure of the soft rock slope. The deformation and stability of soft rock slope under excavation and rainfall, as well as the effect of the supporting system on slope deformation are analyzed by physical modeling. It is suggested that the immediate supports are necessary to decrease the deformation of slope under excavation. Meanwhile, the supporting system can effectively restrict the creep deformation of soft rock slope, especially for the areas of the middle and bottom of the slope.

The consolidation problem of double-layered ground with impeded boundaries using vertical drains for soil improvement is studied based on the existing consolidation theory of double-layered ground with vertical drains. The corresponding solutions are presented and it is coded into a program. An engineering case is analyzed using the program and parametric studies are conducted to study the consolidation characteristics of the double-layered ground with impeded boundaries improved by vertical drains. The results lead to the following conclusions: The greater the values of impeded parameters (Rt and Rb) are, the faster the pore pressure of the system dissipate. Impeded parameters have greater influence on the stratum close to the impeded boundaries than that stratum far away from the impeded boundaries. The difference between the average consolidation defined by pore pressure and that defined by settlement is influenced by impeded parameters.

Based on the theory of fracture dynamics, the analysis of the interaction of longitudinal wave and crack, and the dynamic fracture toughness of concrete, the deep or the perfoliate crack propagation of mass concrete under blasting longitudinal wave was studied; the safe peak particle velocity (PPV) for concrete with crack was obtained; and the effect of the frequency and the incidence angle of longitude wave was studied. The result indicated that the lower frequency and the higher incidence angle of longitudinal wave will easily lead to the crack propagation. On condition of frequency at 10 Hz and incidence angle at 90 degree, the safe PPV of concrete with crack is 0.95 cm/s; it is lower than the value on the handbook of construction planning of hydraulic and hydroelectric projects, which is 5 cm/s for concrete gravity dam and concrete sluice board, the concrete with crack is easily been destroyed.

The paper performs meso analysis of disturbed state concept theory(DSC) which based on hardening model. DSC permits obtaining softening response by using hardening model. In meso analysis, the comparison between softening clay and hardening clay, through antitheses of experimental results under shear loading in macro vision along with synchronous outcomes of computerized tomography real-time test in micro vision, and the relationship between clay hardening or softening and their corresponding CT value changing, explains the logical rationality of disturbed state concept theory problem analyzing and solving. The rationality lies in the correspondence of CT value changing to whether or not superpose the disturbance factor D according to hardening or softening. A new disturbance factor evolution function is put forward. In the evolution function the mean of CT value variance of each scanning stratum is the independent variable. Examples show effectiveness of the evolution function.

Forecasting the mining subsidence is a prerequisite for reducing or preventing the mining subsidence tragedy. But it is hard to apply the traditional probability integral to forecasting the complex solution mining subsidence. So sufficiently considering the anisotropic overburden under complex geological conditions and the irregular rock salt cavern, a new probability integral 3D forecast model is created. And the parameters of 3D forecast model are studied from mechanics angle; and the relation between the model parameters and overburden mechanical parameters is got. The model can exactly forecast the mining subsidence that is caused by complex geological conditions and the irregular working out area.

Based on the dynamic governing equations of elastic waves, a hybrid finite-infinite element method is proposed for analyzing axisymmetrically vertical vibration of saturated media. Using the compiled program, the surface vertical displacements of the air-saturated ground (dry soil) are calculated under a surface point excitation, which are agree well with the theoretical solutions of the Lamb’s problem. The velocity admittance curves of block on single-piled composite foundations in saturated soil with varied permeability are calculated with the conclusions that the soil permeability will have few effects on the velocity admittances of block at low frequencies and on the resonant frequency, while the velocity admittances of block at high frequencies will increase with increasing permeability coefficient of soil. The conclusion will be of guide significance on further research of dynamic test method for engineering parameters of composite foundations in saturated soil.

Based on model test and numerical simulation, the research on displacement of a gravity anchorage of a suspension bridge has been carried out. The model test is carried out with geometrical scale 1:100 and soil mass force scale 1:1.325. Numerical simulation adopts the same conditions of the model test. The Mohr-Coulomb yield criterion is used for soil. Anchorage and pit-supporting structure are regarded as elastic mass. Parameters are chosen according to the similar material of the model test. The research gives the displacements of anchorage under different load conditions. For the designing load, it is shown that the anchorage itself has horizontal displacement and rigid rotation with forepart sinking and back-end heaving. Displacement increase with the designing load added. In addition, the soil improvement, pit-supporting structure and surrounding soil mass contribute greatly to the stability of the bridge anchorage.

A method of back analysis of initial stress fields from displacement is presented based on a kind of modified support vector machine named ?-SVR and a kind of modified genetic algorithms. By using orthogonal experiment method, only several positive analysis are done. ?-SVR used the measuring points’ displacement and parameters of positive analysis as samples to build the nonlinear implicit equations between them. Then modified genetic algorithms are used to find the optimal parameters on deterministic or stochastic optimal object function. The equations built by ?-SVR can fit and forecast the measuring points’ displacements under different parameters with high precision. So these equations can substitute positive analysis, and the amount of computation will reduce greatly. With modified genetic algorithms, the optimal parameters can be found accurately. Example shows the method presented is an effective back analysis method for initial stress fields from displacements. It can be widely used in deterministic or stochastic back analysis of initial stress fields from displacements.

A new method of stability analysis of slopes is presented based on Panjiazheng extremum principle and harmony search method. The harmony memory search method is used to locate the distribution of inner-forces acting on the sliding mass above the given slip surface, which endows the given slip surface the maximum factor of safety. The harmony memory search method is adopted to search the critical slip surface, which has the global minimum factor of safety. And also the new method is applied to stability analysis of two soil slopes. The comparisons of the computed results with that by conventional analysis method have shown that the new method is feasible and applicable to the slope stability analysis.

The Ruins of Jiaohe is a national major preservation unit of cultural relic. As an ancient earthen city site, it is more intact and biggest in the world currently. The Observation Platform is a major and typical building in the Ruins of Jiaohe. The primary damages of the Observation Platform include surface weathering, unstable roof of cave and many crannies. Based on analysis of the damages forming, some key techniques of protection and reinforcement of earthen site have been studied. It is suggested that when the depth of base recess is less than 30 % the width of the block and is very smaller than thickness of cantilever block, it should not be repaired and only used the method for preventing surface weathering. With bamboo-wood anchor and PS-C grouting, the anchoring unit power of wood can be adopted 5 kN/ m by test. NATW, the technique for reinforcing the roof of cave, can acquire effective result for preserving its appearance. In the arid region of western China, when applying PS material to reinforce ancient earth-structure sites and prevent the surface weathering, we should adopt low density (smaller 5 %) of the PS, and the method of many times penetrating. The number of permeating should not be less than 3 times in windward side, and should amount to 4-5 times in leeward side. The reasonable working-time needs choice. By the examination of engineering practices, ideal result has been obtained after applying these protective techniques.