The interaction between the two kinds of internal length scales is analyzed when the gradient-dependent plasticity is introduced to a multiphase material model to study the dynamic strain localization phenomenon of saturated and partially saturated porous media. The stability analysis demonstrates that the resulting enhanced porous media model preserves the well-posedness of the initial value problem for both axial and shear waves because an internal length scale dependent on the gradient parameter is introduced. On the other hand, the seepage process of the water also provides an internal length scale for strain localization analysis via the Darcy’s law but only in the case of compression wave propagation (and not in the shear wave case). It is thus that the length scale introduced by the gradient dependent model and that naturally contained in the governing equations of fully and partially saturated model can interact with each other in a finite element analysis. A basic method is presented to investigate the internal length scale of the porous media under the interaction of these two kinds of length scale parameters. Material stability analysis is carried out for a certain permeability from which the results of wave number domain with real wave speed are distinguished.

The proportional model test of seismic response of bridge of pile foundation in liquefaction ground is done by a large-scale shaking table, which can commendably recurrence the main phenomenon of ground liquefaction and structure breakage arisen from natural earthquake. In input of 0.15gEl Centro wave, the upside of the saturation sand stratum is partly liquefied; the low-frequency response of acceleration appears on pile and pillar frusta; and the peak value of pile dynamical strain fastly aggrandizes from bottom to top; and moreover, largely minishes up to toft surface. In input of 0.5gEl Centro wave, the saturation sand stratum is entirely liquefied; the low-frequency response of acceleration also appears on pile and pile is broken; and the peak value of pile dynamical strain fastly aggrandizes from bottom to top, and moreover, largely minishes up to toft surface. It has importantly influence upon dynamic response of pile and pillar frusta that the saturation sand stratum is liquefied or not.

Based on different classes of surrounding rocks, the numerical simulation of construction process is studied for three roadway tunnels with small spacing, adopting the typical method of double side excavation. The damage characteristic and the deformation law of surrounding rocks are given in the construction process for the different classes of surrounding rocks of three driveway tunnels. The comparability of the distributive law of deformation along the tunnel boundary is indicated for different classes of surrounding rocks; and the relative ratio of maximum displacement is obtained. By comparing the deformation and the plastic damage law in the interval wall between tunnels, the minimum spacing is selected for engineering design reference in three roadway tunnels. It is shown from analysis that the reasonable spacing is more than 0.45B for surrounding rock class II and between 0.35B and 0.45B for surrounding rock class III and between 0.20B and 0.35B for surrounding rock classification IV and V. The key locations of measurement and control are given for the feedback information construction, and these provide the reference data and the theoretical basis for the development and construction design of highway tunnels with small spacing.

Historic breach at the dyke is the most important position for flood-control. Taking historic breach at the dyke of Jinglonggong in the lower Yellow River for a representative example, the measures to control seepage are analyzed by formula method and the finite element method .The results show that the relief well is an effective measure to control seepage in historic breach at the dyke of Jinglonggong in the lower Yellow River.

The double yield surface elastic-plasticity constitutive model and the loading-unloading criterion are considered in this paper. The deformation of soil skeleton and the pore water pressure are also analyzed as the coupling variable. The procedure of single-point and single-time impacting is simulated by using the finite dynamic element program DCFEM which is suited to stratified soft soil foundation. The results of calculation show that the peak stress, peak pore water pressure and peak deformation are delay with the increasing of depth and radial distance to center of the hammer bottom. The stress wave transmits in ground according to erect elliptical spherical surface; and its attenuation is very quick. The consistency between the computation results and the data measured in-situ is obtained. The effective means simulating in-situ project of soft clay foundation which was treated by dynamic consolidation and drainage method is provided.

A new means with digital image processing technique for deformation measuring of soil specimen in triaxial test is provided. Using this technique, the error of the deformation measurement, which occurs in traditional triaxial test, can be eliminated. The local deformation of any part of the soil specimen can be measured at will. The coming into being and development of shear bands of the specimen can also be determined. The influence of membrane penetration in the test can be analyzed quantitatively. Meanwhile, the deformation process of the soil specimen can also be tracked and recorded. Comparison of the results by digital image processing technique and by traditional method shows that the former is more accurate. It is indicated that for standard small specimen, measuring the middle 40mm part’s deformation can get rid of the influence of the end on the deformation.

Through the dynamic triaxial tests and the resonant column apparatus tests of the tailings material taken from a copper mine, the dynamic deformation properties are studied. From the experiment results, a practical strain pore-water pressure model is given and a formula to forecast the dynamic pore-water pressure is presented. Compared with Seed’s forecast formula, the formula can forecast the dynamic pore-water pressure of saturated tailings material more precisely. Based on the effect of different relative density on liquefaction property of tailings material, a conclusion is drawn that the liquefaction strength will obviously increase with the increase of relative density before the relative density is less than 70%. From the dynamic triaxial tests with different confining pressures, it is found that the dynamic shear stress ratio is less while the confining pressure is more in the condition of the same vibration times. Through the resonant column apparatus tests, it can be found that the damping ratio will increase with the dynamic shear strain increases, while dynamic shear modulus will decrease at the same time. And another conclusion that the relationship between dynamic shear modulus and damping ratio with dynamic shear strain is not sensitive to the confining pressure can be drawn.

Firstly, the definition of damage for rock was improved according to some insufficiency or disadvantages of the definition of damage in geometric damage theory. On basis of it, rock material under stress was abstracted into two parts for failed and un-failed material; and then a new damage model had been created according to differences of two parts under force. Secondly, a statistical damage evolution equation was established by making use of statistical damage theory; and furthermore a statistical damage constitutive model of rock under a specific confining pressure has been set up. Thirdly, the model has been modified rationally by discussing the empirical relation between parameters of the model and confining pressure of rock; and then a statistical damage constitutive model applying to the condition of different confining pressures has been founded. At last, with studying physical signification of the parameters of the model, a way to find critical physical and mechanical parameters reflecting conversion between hardening and softening mutually is initially developed. It could also reflect characteristic about conversion between hardening and softening mutually; and its rationality has been shown compared with its test.

Normally, it is difficult to get the satisfied integration result of the half-space. If it is bonded with the numerical method, the continuum may be gotten. In the paper, the equiareal isometric transformation of the domain area is made. Furthermore, it is applied to the consolidation settlement in the three-phase soil, which is studied based on the Зарецкий Ю. К. Solution. Moreover, the sensitivity of the parameters, such as seepage coefficient, modular ratio and the Poisson’s ratio, are analyzed. Some worthy solutions are presented.

A series of tests were performed to investigate the monotonic and cyclic behavior of the interface between geotextile and soil. A functional module for geotextile drawing test was appended to a large scale cyclic test apparatus for soil-structure interface. The monotonic and cyclic shear tests of the interface between geotextile and gravel as well as geotextile drawing tests were conducted with the apparatus. The interface was found to exhibit strain-softening and obvious aeolotropic normal displacement which was affected by the normal stress. The drawing test results show that the shear strength of the interface is not proportional to the normal stress because of its dilatancy behavior due to shear application. The combination of the shear test and geotextile drawing test is recommended as a rational test approach for a comprehensive understanding of the behavior of soil-geotextile interface.

For the multiformity, complexity of the slide zone clay and unequal of the shear strength parameters in the Three Gorges Reservoir area, the main factors affecting the shear strength parameters including geological representation, specimen size, test number, stress level are reseached, especially for the unequally shattered clay and silty clay, those factors may bring out much more influence. The characters of the slide zone are changed with the different places. The two groups test between the different places and the same characters of the slide zone show that the shear area should be no less than 2 500 cm2, otherwise the shear strength parameters (c, ?) are much unequal. The three groups tests in the same place, 5 or 6 points a group, show that the shear strength parameters (c, ?) have 0.5-1.0 time difference, and show that the test number in a group should be no less than 5 points; the contrast test under the different moisture content shows that the moisture content is more, and the parameters (c, ?) is littler. For the unequal characters of the shattered clay and silty clay, the granules diameters and content of the crushed stone also affect the shear strength. So, tester must sechedule reasonable test scheme according to code, project character, and environment of the slide zone, analyze the parameters according to macroscopical characters of slide zone and actual conditon of test point, then put forward proposition parameters.

The Nakai's sub-loading constitutive model are used to investigate shear band localization in plane strain model tests. Boundary condition and loading speed effects on the overconsolidated Fujinomori clay are investigated using the finite deformation theory for shear band localization. Two obvious shear band patterns are obtained. It is indicated that the dilatancy of the overconsolidated clay, migration of the pore water and boundary constraint control the initiation and propagation of the shear bands.

By the dynamic test, the dynamic properties of the silty sand of Hangzhou Qiangtang River flood protection levee are studied. The possibility of liquefaction is judged by the in-situ and laboratory tests. The liquefaction and dynamic stability are studied by adopting the Biot’s dynamic consolidation equation to do finite element analysis, which can consider the increasing as well as dissipating of pore water pressure during the earthquake. By the inverse analysis method, the acceleration at the basement rock obtained from free surface is inputted as seismic loading. The result will help us to understand the levee behavior during the earthquake intensity of 7 degree.

Chaos is a kind of universal phenomenon of nonlinear system. On the basis of chaotic theory, chaotic characteristics of soft soil foundation deformation of the Pearl River Delta are discussed. Based on engineering characteristics and microstructure of soft soil, radical reasons of chaotic characteristics of soft soil deformation are analyzed; the qualitative analysis and quantitative analysis according to Lyapunov exponents of chaotic characteristic of soft soil deformation are discussed as well. The research results show that all of the maximal Lyapunov exponent ( ) of natural soft soil foundation and all kinds of composite foundation in Pearl River Delta are more than 0; therefore the deformation of soft soil foundation is chaotic. The chaotic theory offers a new effective way for study of soft soil and has broad application foreground in engineering fields.

Based on field testing and numerical simulation results on prestressed anchor cable of suspension bridge with tunnel style anchorage system, the ultimate anti-pulling capacity of prestressed anchor cable affected by anchor length, free length，grouting pressure and the level of combination between grout-cable and rock mass were analyzed. The load and displacement distribution characteristic of anchor cable and host rock medium were compared single anchor with anchor cable group. Due to enhanced toughness and anti-crack of root effect, which were affected by embedded depth(free length),spacing, initial prestress, load history, etc., anchor cables restrained the rock mass deforming toward surface. Anchor length determines the ultimate anti-pulling capacity, but free length has key effect to transfer and disperse stress to wall rock and determines contribution value and occasion while they participated the load applied on tunnel anchorage system. Domino effect occured while the anchor cable group was destroyed.

In light of the existing problem in researching the mechanism of prestressed anchor rope foundation beam system, and based on the loading and deformation compatibility relation of foundation and foundation beam of prestressed anchor rope foundation beam system, through decomposition and discretization of prestressed anchor rope foundation beam system, a new theoretical calculation method that can consider the interaction of prestressed anchor rope foundation beam system, is proposed. A case comparative calculation with testing data shows that the proposed method is feasible.

The special properties of high liquid limit soil and red clay of Zhucheng highway are revealed through laboratory test. Based on the characters of high liquid limit soil, the modified experiments are completed by adding lime to the high liquid limit soil; and the change laws of the physical and mechanical properties and strength are studied. The results show that, after being improved by lime, the high liquid limit soil can be used as subgrade filling of expressway as its liquid limit and plastic index being reduced, the dilatability decreased and the value of CBR increased remarkably. In addition, the corresponding contents on the high liquid limit soil and the red clay that are not rigorous in “Specifications for Design of Highway Subgrades”, are discussed so as to contribute to the rational use of high liquid limit soil and the red clay and the renewal or amendment of the corresponding technical specification.

In order to explain the failure and breakage mechanisms of structural geological materials, the plane strain compression tests of the samples of prismatic structural bodies assembled in two different patterns are conducted under different confining stresses. During the breaking process of structural bodies, it is found experimentally that the main failure modes of structural bodies are splitting, shear failure and crushing, but finally the breakage bands form; while the confining stress increases, strain softening gradually turns to be strain hardening; when the lateral stress is low, strain softening and volume expansion and lateral extrusion can be observed; however, when the lateral stress is high, strain hardening, volume contraction and lateral contraction become prevalent; whatever the confining stress is and which pattern the structural bodies are assembled by, the rotation of the structural bodies is hardly observed.

In view of the structural characteristics of natural soft soil, a damage parameter for reflecting structural disruption is proposed in order to consider a continuous structure damage process of soft soil. Damage function is introduced in elastic and plastic modulus expression of the bounding surface formulation directly; then a bounding surface damage model for structural soft soil is developed; the complication induced by introducing damage parameter into the bounding surface equation is avoided and its numerical implementation is easy for the analysis of earth structures. The theoretical predictions are compared with triaxial drained and undrained compression test results of a marine soft soil; it is shown that the model is reasonable.

The identification of slip surface for a landslide is mainly based on drilling holes combining with experience of engineers. A brief method to identify weak layer or slip surface existing in a slope is presented by analyzing vibrating signals induced by blasting. The vibrating signals is collected from earth surface in the vicinity of blasting center. At first, the theoretical base of the method is briefly described. By analyzing the signals from in-situ testings, we conclude that the number of drilling holes can be reduced; and the precision for identification of slip surface of a slope can be improved by using this method.

The principle of 3D elasto-viscoplastic block element method is introduced. This method exclusively takes deformation and strength property of the discontinuities into consideration, with the assumption that the rock blocks are rigid. The governing equation is deduced on the base of the equilibrium equation of block system, the compatible equation of displacement between the discontinuities and blocks and the elasto-viscoplastic constitutive equation of discontinuities. In right abutment slope of Longtan Hydropower Station, the geology is complicated, and the stability of blocks is a serious question. The 3D elasto-viscoplastic block element method is adopted to analyse the stability of the given blocks limited by the typical discontinuities, a series of safety factors of strength reservation under various work conditions are obtained. In the same time, the sensitivity analysis is performed aimed at such important factors influencing the stability of blocks as geometrical and mechanical parameters of discontinuities to provide proposals for engineering design. The application indicates that, as a new numerical method for hydraulic engineering, the elasto-viscoplastic block element method has the merits of validity, practicability and convenience for the stability and deformation analysis of block slope with complicated geology.

During construction of Hepingdong Bridge – Sun Palace thermal power pipeline in Northern third loop road of Beijing City, the pipeline tunnel would go through beneath a couple of single-floor houses, whose area is 23.4 m×24.5 m. Due to the shallow overburden and the saturated microfine sandy clay, which is plastic and soft plastic, the strata is very weak in resisting interruption. The traditional dewatering is limited to improve the nature of the strata. Based on calculation, it is believed that the common construction method would necessarily cause much settlement and endanger the houses. Meanwhile, as the strata are hard to stand up, safety problems may be triggered in construction. In view of these, the level long steel pipes are adopted to support soil mass and grouting in the upper half face of the tunnel is operated to prevent ground water and strengthen soil without dewatering. These two methods effectively control the settlement of ground surface and ensure the perforation of the tunnel in time and running of the houses in security.

GIS (geographical information system), with its capacities range from conventional data storage to complex spatial analysis and graphical presentation, is becoming a powerful tool for geotechnical engineers. In this study, combining the GIS grid-based data with four proposed column-based 3D slope stability analysis models, a GIS extension, 3DSlopeGIS, has been developed to implement the algorithm in which all the input data are in the same form of GIS dataset. Some widely addressed examples have been evaluated and an actual 3D slope problem has been analyzed. The results show the correction and usability of this GIS-based tool for assessing the 3D stability of a slope.

Further analyses are performed on the statistical penetration meso-model proposed by authors in part one. Firstly, method for calculating the macroscopic permeability using statistical penetration meso-model is discussed. Then in order to analyze the evolution of permeability in the process of rock failure, anisotropic damage model is introduced to perform the mechanical analysis, and the coupling analysis method using statistical penetration meso-model and anisotropic damage model is also discussed. Finally, permeability variation of Lac du Bonnet granite is analyzed using the methods above, and the theoretical results by statistical penetration meso-model perfectly agree with that measured in situ before rock cracks fully linking up.

The 3-yield surface model developed by Shen (1984), is one of the most widely used model in civil engineering in China, which has three surfaces, compression yield surface, shear yield surface and dilatancy yield surface. The SMP criterion (Matsuoka and Nakai, 1974；Matsuoka, 1976) is one of the best criterions for the soil in the world. By using the transformed stresses, the 3-yield surface model is combined with the SMP criterion. The revised 3-yield surface model is the same as the original model in form. Comparisons with the experimental data show that not only it can well describe the stress-strain behaviors of the soil, but also can well describe the bifurcate behavior between the strains and stress. The transformed stress method is simple and effective.

Assuming that the failure surface to be an inclined plane through the slope toe, and based on the classical plasticity theory and the generalized plasticity theory respectively, the computation formulas of the reinforced slope’s critical height are deduced. Comparing to the previous experimental values of the reinforced slopes, although the critical height with the generalized plasticity theory limit analysis method is slightly higher than the critical height with the classical plasticity theory limit analysis method, and it is more close to the experimental values; both of them are reliable in the engineering; and they can be used as reference for reinforced slope design .

The prediction of rock mass displacement and their surface effects is an important problem of the rock mass mechanics in the excavation activities especially the metal and nonmetal mining in mountain areas. Based on results of the statistical analysis of a large amount of measured data in mining engineering, the fundamental theoretical model of ground surface movements due to underground mining is established by using the theory of probability. The formulas of rock mass displacements and deformations are developed and applied to the prediction of the ground surface movements due to underground mining in Yi-chang mining areas. The agreement of the theoretical results with the field measurements shows that our model is satisfactory and the formulae obtained are valid and thus can be effectively used for predicting the movements and the natural slope failure due to underground mining of phosphorus ore-deposit in mountain areas.

Based on the laboratory tests to test the relative density of medium-course sand in bridge and culvert backfill, a three-dimensional numerical calculation is made. During calculation, P.V. Lade model and rigid-flexible attachment model are applied to simulate the whole test process. After that, the stresses, strains and displacements around the test cone are disclosed; and the laboratory results are well proved; the mechanism of static penetration in backfill sand is well obtained. It shows that the static penetration can be applied to test the density of medium-coarse-grained sand in bridge-culvert backfill.

In probabilistic slope stability analysis, the correction factor for the safety factor from Spencer's procedure and the theory of the soil properties random field have not been investigated fully. First, since the value of the correction factor is uncertain; it was modeled by the probability distribution shown in this paper. On the other hand, the theory of local average random field is applied to calculate the reliability index. Based on the above, an improved method is proposed to search for the reliability index of slope stability.

In light of the complexity of damage behaviour of the steel fiber reinforced concrete(SFRC) uniaxial compression, Weibull distribution phenomenological method and equivalent strain hypothesis theory were used to found the constitutive model of damage of SFRC. Based on experimental data, parameters of a constitutive model were established. The analytical results show that the given model can describe the mechanical capability of SFRC under uniaxial compression.