The anisotropic mechanical behaviours are widely observed in the saturated and partially saturated geomaterials. This paper makes use of a anisotropic constitutive model developed by Rudnicki for geomaterials to model the anisotropic mechanical behaviors of saturated and partially saturated porous materials in axisymmetric compression test. Conditions for localization of strain into a shear band in fully and partially saturated porous media are derived based on the discontinuous bifurcation approach. The critical modulus, shear band angle and discontinuous velocity vector for localization of undrained condition in axisymmetric stress state are given in explicit forms. The effects of material parameters and pore fluid on localization are investigated in detail by numerical computations.

In classical hydrodynamics in porous media, advection-dispersion equation is employed to describe solute transport in fluids and no deformation in porous media is taken into account during the transport process. Aiming at considering the influence of deforming porous media on solute transport, a flow and transport equation for deforming porous media for two-dimensional problem has been derived by means of mass balance law. Analytical method and solution strategy are discussed.

Natural sedimentary soils are generally subjected to the effects of soil structure. The destructuration of soil structure affects significantly the mechanical behavior of structured soils. However, the destructuration of soil structure is still not well understood. In this study, oedometer tests and triaxial consolidation undrained shear tests are performed on two natural sedimentary clays to investigate the mechanical behavior of structured soils. A new concept on the destructuration of soil structure is proposed based on the strength behavior of structured soils. The effects of soil structure disappear completely when the applied stress is larger than the consolidation yield stress. This new concept can also explain well the compressive behavior of structured soils.

The stress path is a very important factor effecting soil stress-strain relationship. A new stress-strain increment model considering stress path is proposed based on triaxial compression tests of Japanese Toyoura sand. The dilatancy of sand is described by use of a hardening parameter proposed by authors. The three-dimensional stress-strain behavior of sand is described by a transformed stress tensor based on the Spatially Mobilized Plane (SMP) criterion.

The paper sets up plastic strain gradient plasticity increment constitutive model of rock based on adding rock’s internal length parameter in the yielding function.And then, analytic expressions between the strain localization band width and its inclination angle in plane strain is presented based on von Mises’ yielding criterion .Conditions of maximal value and minimal value of the strain localization band width and critical angle of rock destroy are obtained .Variation of inclination angle of the strain localization band is discussed in the difference of Poisson’s ratios and . At last, coefficient of internal friction in Coulomb-Navier criterion is explained by the strain localization band width and inclination angle.

Because of the change of water ratio, the mechanical properties of swelling rock, such as the elastic modulus, Poisson’s ratio and yield limit etc., will be changed. As of the result of water ratio effect, the swelling stress, plastic flow and yielding criteria which varied with the water ratio, etc., all of these will be coupled together. This paper proposed the elastoplastic constitutive model of swelling rock based on the humidity stress field theory and by using parametric variation principle to establish the numerical variation principle and its corresponding finite element form to solve this kind of problems.

A physical study of slope stability has been done by means of geotechnical centrifugal model test to investigate the influence of presence of soft stratum immediately over inclined bedrock on slope stability and failure mode. And the limit equilibrium method based on the failure mode of translational slide is used to predict the factor of safety against sliding simulated in the model tests. It is found from the centrifugal model tests that, in the case of a thin layer of soft soil with lower shear strength over the inclined bedrock, the slip plane is close to the bedrock, and that lateral displacement at failure is of equal value almost throughout the entire slope mass, exhibiting a typical failure mode of translational slide. It is also seen that, in the case of absence of soft soil layer over the inclined bedrock, the slip plane is away from the inclined bedrock at a distance, and that the slope mass above the slip plane is of translational slide whereas the slope mass under the slip plane is of forward tilt slide. It is shown that the stability of slope is not solely determined by the average shear strength of slope soil mass when soft stratum is present over bedrock. It is confirmed that the suggested limit equilibrium analysis is able to predict the factor of safety of a slope on inclined slope by comparison of the factor of safety measured by physical centrifugal model test and the calculated one.

Fifty four pull-out tests between geogrid and expansive soil, sand designed by orthogonal table L9(34) were performed, the variable rules of friction parameter between reinforcements and soils (FPBRS) defined by different criterion have been given, as well as the affecting degree of factors influencing on FPBRS. And in accordance with concept of ‘equivalent pull-out displacement’ presented and the performance of FPBRS, the whole process of pull-out tests were divided into two parts and three stages, with which the FPBRS could be reasonably gained in various displacements states, thus it’s possible to gain the FPBRS both in limit state and working stress conditions.

When a railway or highway tunnel runes through a carbonate area with high groundwater table, the groundwater gushing out is often drained in a long period. The drained groundwater will accelerate the course of hydro-chemical dissolution course of joints and surrounding rock, which will cause the evolution of permeability of surrounding rock mass. To illustrate the course, a hydro-chemical dynamic method is adopted: two parallel boards are adopted to simulate the joints, and PWP equation to simulate the hydro-soluble mechanism. According to the evolution of joints width, the evolution equation of permeability is obtained so as to provide referenced data for the design of tunnel drainage facilities and lining.

Based on the existing soil engineering test data of many expressways, and through a lot of nonlinear finite element method calculations, a general settlement modification formula associated with filled height of embankment and soil compressive coefficient of roadbed, is put forward. This formula can cause the unilateral e-lg p method results to consider soil lateral deformation and validated by two engineering examples. The results show that the settlements modified by this formula have less errors, it is not only more reasonable than criterion method but also more closed to the measured data. In a way, this method can be used for reference in other engineering.

Creep is an important property of geosynthetics for its application in any permanent reinforced structures. The principles and effect factors of creep, testing equipments and operating procedures, time-temperature superposition and stepped isothermal method for decreasing the lasting time of creep test and a comparison of different cords are presented. Meanwhile, dynamic creep test, creep tests of geoform and geosynthetics clay liners and combined analysis of installation damage and creep are briefly introduced. Finally, some suggestions about research on creep of geosynthetics are given.

It’s necessary to consider interaction between buried pipe and soil when analyzing its structure between pipe and soil, which comes down to the determination of contact stress distribution on the interface. Thus, on the basis of measured data of stress characteres of buried pipe, a composite model for analyzing interaction between pipe and soil and a method for determination of its related parameters are presented. For the apparent effect of relative stiffness between pipe and soil as well as that between pipe and foundation on distributed stress on interface between pipe and soil, the paper adjusts parameters of the model by taking use of measured data. So influence of pipe stiffness can be taken in consideration in this interaction model as a result.

Rainfalls and soak often lead to landslides of soil slopes. Undoubtedly the lost of part of matric suction is one of the most important factors. Through tests and numeral computationes, it is shown that the matric suction plays an important role in slope stability. But to make certain one of the key parameters in unsaturated soils needs further researches.

Using information theory, fuzzy matter-element and analytic hierarchy theory, an information entropy fuzzy analytic hierarchy process model is established based on analyzing factors of deep foundation pit retaining system. The model solves the multi-objective optimization decision making problem of deep foundation pit retaining which is influenced by many fuzzy and unstable factors; and provides a new way to select deep foundation pit retaining projects.

Dynamic compaction is one of methods for groundwork treatment. But the vibration during dynamic compaction often becomes a problem that restricts the application of dynamic compaction. Combined with dynamic compaction vibration of a harbor engineering, the law of vibration propagation and attenuation is presented. Based on the monitoring data, the influence of the vibration on environment is analyzed and measures for preventing dynamic compaction vibration are put forward. Scheme was provided according to effect of treatment on depth.

Based on governing equations of saturated porous media and Liapunov’s stability, the onset strain localizations of porous media that formularized by solid phase stress and effective stress under seepage flow state are presented here. The onset strain localization conditions are different with expressions of governing equations of porous media and the constitutive model of porous media. With the derived onset strain localization condition of Terzaghi’s effective stress, some failure modes in porous media caused by two kinds of relative movements between solid phase and fluid phase have been discussed by means of examples.

In this paper on the basis of the 3D rigid body limit equilibrium analysis with vector numeric method, the calculations of several common loads are discussed. Especially the algorithms of various assumptions in seepage load calculation are implemented, including node setting method and block height decreasing method in groundwater level definition. It has been applied to the slope stability analysis of Xiaowan Power Station water intake and some results with practical value have been obtained.

It is well known that the correct division of engineering geological strata groups of rock mass is the basis of rock mass quality evaluation. When many soil layers were revealed, especially in large projects, it is necessary to divide the engineering geological strata groups of soil mass either. The division is helpful to show the geological structure of the site more clearly, make it convenient to generalize the engineering geological model and study geotechnical parameters on the basis of the model and is helpful to capture and evaluate the primary engineering geological problems. Furthermore, it is easier for the architects to understand and to apply to. Taking the Nanjing Metro for example, the issues of the division are discussed. Through the statistics of discrete data acquired from the divided strata groups and analyses on the engineering geological models and problems, the rationality and significance of the division is noticeable.

Field pour concrete cased pile with vibrated and steel tube mould technology is a new ground improvement technology developed independently by Hohai University. This new pile style is suitable for soft areas. Load transfer is studied by means of an axisymmetric finite element elastoplastic model that includes interface elements for representing slippage , pile-soil separation and soil nonlinear behavior. Numerical results indicate that good agreement exists between the finite element prediction and the field test for the head load-settlement curve. Inner frictional resistance, outer shear stress, end bearing and effects of soil plug those can not be investigated by field test are also studied.

Time and depth were adopted to analyze excess pore water pressure (EPWP) due to driven pile in soft clay; and a 3D analytical formula was derived. Principle of EPWP dissipation process was discussed. Position and time that Mandol effect of the soil around the pile happened were analyzed. A model to calculate EPWP due to pile groups was established: during piles driving, EPWP in soil accumulates and dissipates; after that, EPWP dissipates only. And effects of pile spacing and driving order of pile group on EPWP were analyzed.

Seismic stability and permanent displacement of cover soil in a solid-waste containment system are performed using the discontinuous deformation analysis (DDA). The effects of the inclination angle, the friction coefficient of the soil-geosynthetic interface, the length and thickness of cover soil and the earthquake strength on the stability and permanent displacement are discussed. The failure mechanism of cover soil in a solid-waste containment system is also discussed. Numerical simulations are done to testify and compare the two-part wedge theory proposed in literature [1]. Parametric study indicates the applicability of the two-part wedge theory. At the same time the seismic design suggestions are proposed.

In landfills, geomembranes are commonly placed on the slopes to isolate waste from the surrounding ground. Placement of soil cover and waste layers over these geomembranes will result the shear stress on the liners and lead to developing significant linear tensions and displacements which are necessary to be studied so as to ensure the safety use. This paper took into account the essential stress-strain compatibility and used the hyperbolic curve to model the interface shear stress-displacement between the lower interface and soil, then got the governing differential equations. The equations were solved numerically using a finite difference combined with iteration method. Finally, the important factors which influence the behavior of the interface between the geomembranes and soil, are studied.

The Mohr failure envelopes for rockfill exhibit significant nonlinearity at high stresses. Nonlinear strength is described by exponential and logarithmic mode. Stability analysis of high rockfill slope indicates that safety factor of nonlinear analysis is bigger than linear analysis. Safety factor based on linear rule should be properly increased. A criterion of safety factor is suggested.

On the basis of large-scale triaxial tests for rockfills, the exponential function expressions about the relationship between deviatoric stress and axial strain or relationship between lateral strain and axial strain are proposed respectively. In addition, the failure envelopes of the rockfills in the planar coordinate system of octahedral shear stress and octahedral normal stress also can be described by the exponential function expressions. A nonlinear elastic constitute model is derived from these results which is suitable to shear strength and deformation characteristics of rockfills. Some analytical comparisons between Duncan E-B model and the new model proposed are carried out by means of simulation of an engineering instance, so as to confirm the feasibility of the new model.

The liquefaction distinguishing method of sands based on standard penetration tests is compared with the simplified procedures, and the reliability of the method is discussed. The study indicates the probability of liquefaction of sands evaluated by the method of Chinese Code varies considerably. For the 7°aseismatic zone, the liquefaction probability is between 0.17 and 0.42 and that of simplified procedures is 0.36 to 0.43. The liquefaction probability is up to 0.65 to 0.70, greater than the probability of simplified procedures for 8°and 9°aseismatic zone. Comparison with simplified procedures, the liquefaction distinguish method is unsafe. The liquefaction probability of sands with high fine contents is greater than that of simplified procedures; especially the liquefaction probability is up to 0.9. It is obvious that the safe margin can’t be satisfied. The future study on the term of fine contents of the liquefaction distinguishing equation should be motivated.

Exponential trend model is applied to forecasting the displacement values at observation point GA in Lianziya hazardous rock mass. It is a new method which forecasts the deformation and failure of the slope. At first, nonlinear exponential trend model is linearized, and undetermined parameters are determined using the least square method; and then the exponential trend model without undetermined parameters and displacement values of forecast have been obtained. The errors of the results of forecast and actual displacement values are very little. It shows that this method may be used to forecast the displacement values in the deformation of slopes (landslides); and the effect is good. Finally, the interval and interval length of forecast values are also estimated.

A method for computing ratio of pile stress to soil stress of a rigid pile composite foundation with cushion, is studied; and the conditions that the top of pile piercing into cushion and the bottom of pile piercing into underlayer, are considered. It is assumed that cushion is ideal elastic body and ideal elastoplastic body, then the formula is analyzed; and all parameters’ effects on the ratio of pile stress to soil stress are discussed.

Red sandstone landslides are widely existed in expressways. Investigation and treatment of landslides in two expressways are summarized. By the following research, we can see that the instability of slope is highly correlated not only with the along-slope of sandstone-layer, weathering and developing level of joint, but also with the surface pattern of earth and the penetrating condition of surface water. Experiences are accumulated to apply to the similar projects and reduce the landslide result from slope excavation through the summary and analysis. At the same time, it might be used as reference for the personnel who design, construct or supervise the similar projects.

This article analysis one gangue-dam’s anti-slide stability coefficient affected by dam hightening, soakage string character, running conditions of the drainage systen and lens decreaseing. The gangue-dam’s anti-slide stability coefficient decreaseing with the dam hightening, but the amplitude doesn’t as hard as the soakage string’s which is influenced by the running conditions of the drainage system. Lens decreaseing under some certain rules can simplify the section map and decrease the analysis complexity, it can also reflect the engineering geological prospecting, although the result might be a little conservatism. Imitate statics method can not fit for all the gangue-dam anti-slide stability analysis, even though more windage may appear in the result.

Based on introducing the principle of VJC-RMR method (Volumetric joint count-rock mass rating method), rock mass modulus of deformation and quality of dam foundation of Yujianhe Reservoir in Guiyang City are evaluated and compared to in-situ test, Q method (Rock mass quality) and fractional model of rock mass damage. The results show that the VJC-RMR method is a good method for evaluating rock mass quality and determining rock mass parameters. The method can reflect real condition and transform one dimension into three dimension．

According to geological conditions and engineering loads of different zones of a harbor project, a series of dynamic compaction tests with different techniques were performed. Ground deformation around ramming points , horizontal displacement in soil mass and pore water pressures were monitored; and compaction effectiveness was test. Research results show that it is feasible to treat the saturated soft soil covered with hydraulic fill sand by dynamic consolidation method, of which effective improvement depth is six to seven meters; and the depth of hydraulic fill sand influences remarkably on effective ramming power and function of gravel-soil cushion. Vertical drainage measure may not be taken because of presence of hydraulic fill sand layer and silty sand layer if improved depth to need is shallow. By analyzing the measuring data, the optimal parameters and construction techniques are obtained; and the depth of hydraulic fill sand shall be taken into account when construction techniques is chosen.

According to the natures of embankment fill of Huaiho River Waterway to sea, filtration erosion tests were performed on embankment fill. Based on the results of tests,the impervious property and the kind of filtration erosion of embankment fill are then discussed. The construction control measures, construction quality requirement and anti-seepage measures are also discussed.

Our research team had a test in situation on Net Management Center Mansion of Shaanxi Telecom Office, and got some distribution rules of settlement, reaction of soil among piles, pile’s reaction, the proportion of load carried by pile and soil among piles. The analysis results can be used in real structure design and computing theoretical research of high-rise building in loess area.

In underground space, the ground penetrating radar can be used to determine position and strike of a fault by probing in horizontal direction. Also this method may find dip, hade and throw of a fault by probing in vertical direction. However, it can not be used to describe features of fillings in fault plane in detail. That is, finding some parameters of faults accurately has geological and engineering values to excavation and maintenance of underground engineering.

The bolt-shotcrete support structure and a kind of cement-injection technology through bored pipes are applied to consolidate the soil slope of a drainage works and to reinforce the building foundation close to the slope respectively. The mechanism and design method of this technology are introduced. And furthermore, an engineering example is given and it is proved that the technology applied to reinforcing slope and foundations is successful.

On the basis of comparing the plate static loading test with dynamic penetration and dynamic rigidity, a new idea of combined measurement is put forward to test consolidated foundations and a correlation empirical formula is established. The empirical formula can be tried in practical project to quickly test the loading capacity.