According to Shanghai harbor ground treatment project, considering the engineering properties of fine sands and disturbed soft soils underlying it, method of PVD-improved subsoil with two technologies of vibroflotation compaction without additional stone aggregates for improving fine sands as well as well dewatering combining with dynamic consolidation for strengthening the disturbed soft soils underlying the hydraulic fine sands is introduced. Based on results of field tests, large-area vibroflotation compaction construction parameters are determined; and the increasing and dissipation regularity of excess pore water pressure in different soil layers and its influencing factors are analysed. Finally, some useful conclusions are drawn.

Numerical simulations of two-dimensional circular and ellipsoid particulate arrays are carried out based on granular discrete element method. The microscale deformations are measured based on void cells and the deformations occur in them. Deformations within individual voids are computed from the relative motions of surrounding particles. Based on the deformation mechanism, a more physical theory of critical state is developed in terms of valence (number of edges per void cell). Two ultimate cases with large and small friction coefficients are analyzed to define the maximum critical valence. The effects of particle shape, interparticle friction and consolidation stress of the granular assembly on the microscopic fabrics are investigated. The simulation results show that the microscopic critical state can not be characterized by a unique parameter, but depends on the shape and surface characteristic of the individual particles and consolidation stress of the particulate assembly.

According to imbalance thrust model, calculation format of stability coefficient was studied and the corresponding procedure of nubbly rock mass slope can be derived. It is very difficult to establish limit state equation under the condition of the format. An approximate method can resolve the problem. It is suggested that the sample data can be provided according to imbalance thrust analysis model which is used as a means of calculation and realized the smoothing function which takes rock mass mechanical parameters as independent variable as an approximate analytic expression. The limit state equation can be given according to the function and with the design point method slope stability reliability can be given easily. Finally, the stability probability of a project was analyzed by the above-mentioned method and the traditional mean deviations method respectively. Compared with the traditional mean deviations method, the approximate method can meet engineering requirement on accuracy and its calculation workload was decreased greatly. It is indicated that the approximate way is available.

According to the fuzzy probability theory in fuzzy mathematics, a comprehensive fuzzy probability evaluation model of sand soil liquefaction is presented. In order to consider the fuzziness of weight factor, the fuzzy weighted value is suggested to avoid the uncertainties while determining the weight factor. The following factors such as earthquake intensity, standard penetration number, mean diameter and effective over burden pressure are selected as the evaluating indices; and liquefaction grades are classified as the non-liquefaction, slight liquefaction, medium liquefaction and serious liquefaction in the evaluating model; so the evaluation results can be more precise. The theoretical model is successful applied to evaluating liquefaction of sand soils in practical engineering; and the rationality and effectiveness of the method proposed is demonstrated through 22 examples.

Firstly, the results of in-situ testing of Zhoushan National Oil Reserve Base improved by preloading combined with plastic drains is introduced. Base on the in-situ measured data, the change rules of settlement, settlement in layers, deep soil displacement, and excess pore water pressure on soft clay foundation under preloading is analyzed; and further study on consolidation effects according to the analysis of stress and strain, including the empirical coefficient m applicable for the base is gained by the strain analysis. Finally, the result shows that the good effect can be gained on the soft clay foundation treated by preloading combined with plastic drains.

Based on mesoscopic damage mechanics, numerical code RFPA2D is developed to simulate the failure process of rock specimen subjected to dynamic loading; and the failure characteristics of rock specimen under different continued times and different amplitudes of stress wave and different confining pressures are studied; in the meantime the failure properties of rock specimen under static and dynamic loadings are compared. Numerical results indicate that the shorter continued time of stress wave, the narrower high stress area after wave front, the faster stress wave attenuates; On the contrary the longer the continued time of stress wave, the larger high stress area after wave front, the longer time is lasted for rock failure, the more cracks initiates and propagates. Furthermore, appropriate continued time is necessary for cracks of rock specimen to initiate and propagate, and on the contrary excessively long continued time goes against cracks growth. The more amplitude of stress wave, the more the fragmentation degree of rock specimen, and to certain amplitude, comminution mode appears at the top of rock specimen; and the breakage degree wears off from top to bottom of rock specimen. Rock is more difficult to break up when confining pressure increases under high speed impact loading, and rock failure occurs suddenly when confining pressure increases to certain value; By contrast to static loading condition, more cracks initiate and propagate under dynamic loading, which cause the damage and fracture of whole rock specimen.

Based on the results of the field static load test of the screw pile group, some influencing factors of the bearing capacity of screw-pile group is analyzed, and the influences of geometric parameters of pile group on end bearing and friction resistance of pile group under ultimate loading are discussed. From the analysis of testing results, the bearing capacity of screw pile group is obviously influenced by the distance of lamina between screw piles and the length of pile from the first layer of lamina to the base of pile cap. When the ratio of pile spacing of lamina, which is the ratio of the pile spacing to the diameter of lamina, is less than 2, there are not the obvious inflexions and presented the slow change for the load-displacement curve of the static load test of screw-pile group; for these failures of pile group belonged to the general failure. At the same time, the lamina of screw pile is able to promote the reciprocity among pile, soils and pile cap by limiting height of the active zone of deformation of soils under pile cap, and the displacement of pile group is decreased.

The deformation date of 3D geo-mechanics model are composed of the internal deformation of rock mass and convergence deformation of boundaries. Searching the method of measuring the convergence deformation with high precision has been major direction of research in the area of data acquisition for 3D geo-mechanics model. In this paper, the calculation method based on the coordinates transformation of images in the traditional digital camera photogrammetry was revised the small template operation method of 5 ? 5 was improved. Instead, the big templates with the layout of standard points was used and a method of selection for coordinate data of neighboring marked nods was designed, thus, the influence of lens distortion was reduced effectively. The direct linear transformation mechanism based on the BP neural network was used for coordinates recognition of images and comparison of coordinates of marked nods during experiment period. The measurement of convergence deformation for 3D geo-mechanics model was thus achieved. A 3D geo-mechanics model applying the close shot photographic technique of digital camera was set up for a large scale forked tunnels, the results of measurements were satisfactory.

Taking a long sequence test data of physics and mechanics of cohesive surrounding rock as a base, the indices selection of surrounding rock classification was analyzed in a quantitative angle through mathematical statistics theory and grey-relation method. The research results show that the influential factors of mechanical indices are feasible to be basic classification indices. All preelection indices can be divided into three groups. On the ground of the results of grouping analysis and relation degree degree analysis, integration correlation coefficient of indices were calculated. Plastic index, natural density and liquid index have an important influence on cohesion and inner friction angle based on the value of integration correlation coefficient. The analysis results reveal liquid index, natural density and plastic index are the estimation indices of surrounding rock classification in cohensive soil tunnel.

The classical Poulos’s elastic theory is only suitable for the behavior analysis of piles subjected to lateral soil movement in homogenous soil. But it cannot take the layered soil into account. Therefore, to satisfy the characteristics of layer soil, Poulos’s method is modified by using the Mindin’s solution considering a horizontal concentrated force, and also considering the stress &displacement solution under the ground vertical load in sandwich ground, which can be used to study the movement and internal force response of passive pile due to surcharge loading. A calculation case indicates that the modified method is more strict and reasonable than that of Poulos, with a higher calculation precision. The approach proposed can be used extensively.

The bearing capacity properties and the influencing factors to building settlement control factors of the composite foundation disposed with deep-mixing pile are both analysed. In allusion to an actual project which is designed with the settlement-control criterion, the load stress distribution characteristic of composite foundation between pile and soil is also studied by the in situ tests with the pressure sensors set on pile top and nearby soil stress and the pile top stress with the settlement-control criterion. The results of the settlement monitoring show that the value of the building settlement is consistent with the predicted one, so as to prove that the settlement control design of the composite foundation is feasible in thick soft clay area or even with the area that existing the soft substratum.

The formula of square root of time methods play important effect in engineering since Terzaghi gave the relation formula between degree of consolidation and time factor. However the theoretical proving isn’t reported in the journals since then. The theoretical proving of square root of time methods is given; and computed result shows that the conclusion is fit well with series formula.

Based on remote sensing synthetic analysis, the distribution regularities of strip collapsing and arc collapsing along middle-lower Yangtze River are explored. The mechanisms of the two types of bank collapsing, especially the plane eddy mechanism of arc collapsing are discussed. It is considered that the occurrence of arc collapsing is resulted from the forming of whirlpools near some special shores. Using the eddy theory of hydrodynamics, the principles and the method by means of critical negative pressure to evaluate the occurrence of arc collapsing are suggested.

Because of the complicated reinforced mechanism and experimental measure, combining with the reinforced steep slope of embankment engineering, the field test of deformation monitoring has been carried out. In light of the properties of geogrids, numerical calculation is done by nonlinear finite element method. The results from experiment and calculation show that the settlement and horizontal displacement of the embankment laid by geogrids can be reduced and limited at large extent. Therefore, the embankment stability is pledged. The calculated results are consistent with the field measured data. Some factors influencing upon the deformation, including the length, elastic modulus and interval of geogrids, are analyzed. The larger the modulus is, the better the results is. The geogrids with length of 6.5 m and interval of 0.6 m are economical and effective.

New method for handling roof of emptied areas based successive mining is proposed, which is induction caving roof. The effect of induction caving roof is relative to the construct path, the mining method and the order of the induction caving. At the same time, the physical properties of mine and rock are nonlinear material properties (elastoplastic material). The system of induction caving roof is the nonlinear and the time-varying system, The FEM basic equations are built according to the theory of the time-varying mechanics. Then based the geology and the ore characteristic, the 2D FEM time-varying mechanical model is built in the testing stope of the Tongkeng Mine, the technology of the many steps is used to simulate the time-varying mechanical behavior, special the expanding of the plastic zone, the displacement and the safety factor in the tunnel to the two kinds mode of the induction caving roof. The effects are analyzed to the safety of the stope and the influences on the mine technology. The results show that it is advantage to induction caving roof, for which it is the technology the first pre-splitting blasting and the last forced caving. According to the results, it is proposed that the millisecond blasting between the first pre-splitting blasting bolts and the last bolts in the same time.

Composite foundation with rigid-flexible piles under strip foundation is analyzed by means of finite element method on the basis of field test．The influential factors including cushion, cap, rigid pile and flexible pile on deformation characteristics of composite foundation with rigid-flexible piles are studied systematically. The results indicate composite foundation settlement reduction along with cushion thickness reduction and module increment, cap thickness increment is advantageous to differential settlement reduction, rigid pile is main component to control settlement; flexible pile increment can reduce differential settlement. These conclusions are helpful for optimum design.

Rockburst is one of the most important geologic hazards. To solve the problem of classification and prediction of rockburst, the main factors of rockburst occurred and the effective classification methods should be considered., A new method is proposed based on combination of artificial neural networks (ANN) classifiers as weak classifiers by using AdaBoost algorithm in data mining. The AdaBoost-ANN models are established. Overcoming the instability of single classifier, the models can give more accurate and stable classification for the novel conditions. The results show that this method is reliable, constrictive and promising.

A calculation formula of limit to growth length when grout body cracked is deduced from the hoop stress of wholly bonded prestressed cable grout body, which is concurred between the hoop tension stress is created by pretension and the uniformly corrosion expansion force by cable body. An estimation expression of the service life when grout body of prestressed cable cracked is solved based on predecessors’ research production, which is used in high slope of water resources and hydropower engineering. At last, four factors related to service life and their relative importance are discussed, which is combined with the prestressed cable of 2 000kN. It is concluded that: the pretension is the most insensitive factor. With the increase of the pretension, the service life decreases, in which the curve is linear. The influence of the cable body diameter is relatively much stronger than the pretension. With the increase of the cable body diameter, the service life increases, in which the curve’s gradient is slightly steepening. The influence of bond thickness is a little stronger than the cable body diameter. With the increase of bond thickness, the service life also increases, in which the curve’s gradient is slightly steepening. Whereas, the compression strength of grout body is the most sensitive factor that affected the service life. With the increase of the compression strength, the service life increases, in which the curve’s gradient is also slightly steepening.

The conservation of the historical sites is one of the most complicated issues of cultural heritage conservation; and earthen cultural heritage is the most difficult; so the conservation of the historical earthen sites has been listed as the special conservation item. As for the historical earthen sites in moisture circumstances, the task of the conservation and exhibit is more urgent. The Liangzhu Culture of Neolithic period is the most important prehistory culture in the Yangtze River valley and Tangshan Site is located northwest of the Liangzhu Sites. Four protective materials are chosen to implement on Tangshan Site in situ, i.e. PS, WD-10, WD-S, and RTV. The results of experiments in lab and in situ (after 2 months, 6 months, and 9 months) indicated that the waterproof character of RTV and WD-10 are better than WD-S, and WD-10 and WD-S could only be used as waterproof materials, PS could only be used as consolidant but RTV was of favorable waterproof and consolidation effect.

To discuss the influence by the constraint of surrounding soil on the buckling stability of cast-in-situ rock-socketed piles with highrise pile cap, the most general exponential distribution of subgrade reaction modulus was assumed and the total potential energy equation of the pile-soil system was set up based on the simplified elastic beam model. Then, analytical solutions for the buckling length and buckling load of the pile shaft were deduced by applying the principle of minimum potential energy. And based on the obtained solutions, influencing rules by the distribution mode of subgrade reaction modulus, deadweight and side resistance along the pile shaft on the buckling behavior of cast-in-situ rock-socketed piles with highrise pile cap were discussed and obtained respectively in detail. Application of the present method to an engineering example shows that, more reasonable buckling analysis results of the pile shaft may be obtained when the distribution of subgrade reaction modulus is characterized by an exponential function.

The contribution of matric suction and stabilizing piles to the global stability of unsaturated soil slope should be properly evaluated in practice. Methods of design and analysis for slope reinforced with piles are firstly discussed and reviewed. Then, by making use of the strength reduction finite element codes, the global stability of unsaturated soil slope are analyzed. Four cases are combined according to the conditions of stabilizing piles and matric suction. The comparison of results can evaluate quantitatively the effect of matric suction on slope.

For the Yellow River dikes which are reinforced by desilting, the longitudinal cracks appeared in the standardized dikes in Henan and Shandong provinces in Lower Yellow River; it would effect quality and schedule of project badly. Through in-situ search, indoor experiments and theoretical studies such as saturated-unsaturated seepage-stress coupling, soak deformation, the cracking causes are analyzed; and relevant methods of prevention and curing are carried out. The results show that the construction in high speed is the basic cause of cracks of dikes; and soak deformation of dike, bad drainage of desilting section, stacking load at the tip of dike, impact of vehicle lead to form and develop of cracks. Therefore, the cracks of dikes can be prevented by controlling construction speed of desilting, draining quickly at desilting section, avoiding to stacking load at the tip of dike and so on. Moreover, cracks can be settled with core grouting, cutting and backfilling and so on.

The two-dimensional consolidation in saturated soil around sunk pile is studied. Considered the initial distribution and boundary condition of excess pore water pressure caused by setting pile, the series solution can be found by using methods of mathematical physics. The comparison between the calculation values and the consolidation degree values which are deduced from the practical bearing capacity shows that the series solution is reasonable. On the other hand, the consolidation degree results from the series solution can also be used to predict the capacity of the pile.

Under the condition of plane strain, a 2D elastoplastic FEM is used to analyze the behavior of a soil nailing support for deep foundation pit; and stability method based on slip surface FE stress is applied to evaluate the stability of the soil-nailed wall. The variations of tensile force of soil nails and deformation of foundation pit are studied. The influence of different lengths and layouts of soil nails on stability and deformation of foundation pit is also analyzed. The result indicates that the potential slip surface of foundation pit is consistent with the position of maximal tensile force when the soil nails are long enough.

Theory equations and norm equations are primary methods to calculate loose load of tunnel. They are established based on the statistic and analysis of loose load from finished tunnels in general. With the development of road tunnel construction, the two-way and large-span road tunnel with eight-lane in either way become a new shape in recent years. The eight-lane tunnel has an increase in excavation area and a decrease in excavation height relatively for the aim of curtailing the cost of construction and has a smaller ratio of height to width. For this reason, current calculation method of loose load whether or not apply to barge-span tunnel has been significant for tunnel design. In this paper, firstly, various calculation methods are summarized and applied to Longtoushan Road Tunnel with eight-lane and barge-span. And then, calculation results are analyzed and compared. Secondly, rationality of calculation methods for Longtoushan Tunnel is analyzed based on numerical calculation and measured data. Finally, the paper presents and discusses applicability of various methods, especially for the eight-lane and barge-span tunnel, based on its own background and above study course. The purpose of the article is to provide reference for the design of extra-large cross-section and barge-span road tunnel.

Due to the nonlinearity and complexity of deformation evolution of geotechnical engineering , it is difficult to describe it with simple mechanical and mathematical model. A method for forecasting the stress and displacement nonlinear time series is proposed based on constructing radial basis function neural network using particle swarm optimization algorithm .After determination of units’ number in RBF layer using k-means, all parameters such as central position, shape parameter and weights of RBFNN are estimated dynamically in global with particle swarm optimization. The engineering case studies reveal that this model has high accuracy and a good prospect for nonlinear time series forecasting of geotechnical engineering.

Scholars at home and abroad calculate the gravity function separately to perform the un-strip shallow footings bearing capacity. The geometry of failure mechanisms is three-dimensional. Cohesion force, overloading and gravity are coupled to calculate the bearing capacity with limit equilibrium theory. Several parameters influencing the calculation result of bearing capacity are discussed. The factors calculated are typically larger than earlier empirical proposals in the literatures. The comparison of results with existing solution is given to validate the method.

Jacking force and average friction both are important parameters in pipe-jacking construction, the former can affect construction scheme greatly; the latter can embody whether the construction crafts are good. In the construction of a long distance and large diameter pipe-jacking tunnel with small curvature in Shanghai, jacking forces along jacking path are measured for two pipes. Based on the on-site observation, relationship of jacking force and average friction with jacking path and its influence factors are analyzed. Due to complexity of the influence factors, jacking force increases with violent vibration along jacking path，average friction also vibrates initially at high level. As a result of construction stabilization such as formation of slurry-cover, stabilization of axis-control, and dilution of influence factor along jacking path, average friction decreases quickly and tends to stabilize after initial stage. If construction measures are sound, average friction for long distance pipe-jacking with small curvature can be controlled at a low level. At last, some suggestions about construction are put forward.

The slag cementitious material is used as a new kind of binding agent for solidification/stabilization with lake sludge. The mechanism and strength characteristics of treated sludge are studied. The slag cementitious material can greatly improve the unconfined compressive strength of sludge at various curing periods with the 5 % content, while 12.5 % content is optimal for strength development (1.55 MPa at 28th day). The treated sludge strength is high in early period; and the long-term strength is increasing with a good ability of water resistance. SEM analysis shows that pozzolanic reaction occurred in the slag cementitious material and sludge particles, and formed high strength and insoluble mineral cement to decrease the macropores in treated sludge. The binding performance is obviously improved. All those show that the slag cementitious material is a preferable solidifying agent for lake sludge.

According to the specific geological and topographical conditions at dam site of Xiaowan Hydropower Station, fundamental influencing factors and spatial distribution of initial geostress are analyzed. The 3D FEM model and the parameters spatial distribution regression model are built. For each factor, a corresponding calculation is executed with MSC.Marc program. Taking the regression precision as the objective function, the boundary extrusion loads are optimized to simulate the field caused by horizontal compressed tectonic movements. Finally, all parameters of the regression model are estimated. The result of back regression analysis shows that the improved method is available with higher precision, and can simulate 3D initial geostress field more practically. So sa to provide a basis for further exeavating simulation of similar projeets

By regarding the soil portion below the pile as a soil-pile and using the existed results of the soil resistance to horizontally vibrating pile, the dynamical behavior of the composite pile composed of the pile and virtual soil-pile, is analyzed; and the semi-analytical solutions for the dynamical stiffness of viscoelastic floating pile in a viscoelastic soil layer are obtained in the frequency domain. The variations of the stiffnesses with various physical parameters are shown in figures. Then, the influences of the material parameters on the stiffness are discussed; and the behavior differences between more slender and less slender piles are examined. It is shown that the dynamical stiffnesses of the floating piles depend on the pile length, soil property and excitation frequency. The results presented here are helpful for pile design.

How to decide the parameters of bolted rock mass is an important and complicated problem in geotechnical engineering. Taking unloading into account, the variation regularity of compression strength, Poisson′s ratio, elastic modulus, c and friction angle ? values were studied and simulated by computer; and different loading-unloading paths, anchoring angle, strength of rock mass were taken into account. The computed results show that the influence of unloading process before reinforcement should not be neglected. Finally, some experimental data were used to testify the above-mentioned analysis.

In terms of continuity equation, movement equation of transient flow and water head loss theory in open channel in hydrodynamics, the decay process of landslide surge is divided into two stages, respectively, sharp-decay stage and slow-decay stage. And it is assumed that the sharp-decay stage is a kind of exponential decay and the slow-decay stage is a kind of water head loss with propagation distance in open channel. According to both decay rules, the propagation height and climb height of landslide surge along bank are evaluated on basis of initial surge height. Taking Xintan landslide for example, the propagation height and climb height of landslide surge are evaluated. It is concluded that landslide surge increases quickly decays first and then slowly decays; and when the propagation distance is 3 km. the surge height accounts for only 30% of the initial surge height, and accounts for 13% with the propagation distance of 10 km.

The coupling analysis of slope runoff and infiltration under rainfall is one of the important key problems for the research of rainfall-induced landslides and the soil conservation. The subsurface and surface flow coupling equation is established; and the solution can be achieved directly by the method of FEM. Using the method, it is not necessary to calculate the moisture flux that passes the slope surface; and then the computational precision and the computational speed can be improved. The simulation results show that the method is feasible, efficient and stable in calculation.

Based on the stress-control triaxial apparatus, the CU triaxial creep tests of subgrade soft clay under different confining pressures were carried out by using multi-grade loading mode. The full-process creep curves under different confining pressures were obtained. Furthermore, the creep curves of multi-step constant load，the equal-time stress-strain curves were gained by using “Chen method”. Taking the confining pressure 100 kPa for example, a power&hyperbolic creep equation was proposed. In the equation, the power and hyperbolic equation are to model stress-strain and strain-time relationship respectively. Compared with Singh-Mitchell’s model and Mesri’ model, the creep equation suggested is thought to be more suitable to reflect the creep characteristics.

Basing on construction monitoring of the supporting system for a deep foundation pit, a study on the displacement, settlement, inner force and water level are carried out. It is indicated that the horizontal displacements of timbering stakes as well as observation spots outside increase step by step along with the increase of the excavation depth and construction time. Meanwhile its increasing velocity tends to steady gradually. In addition, the displacements are also related to the location of building nearby and the supporting condition. The settlement of building nearby increases with time, and is greater near to the pit. The settlement of standing column and the apophysis of earth are related to the bearing weight and the form of pits. The axial force of support is related to earth condition, support rigidity as well as order and velocity of construction, etc.The partiality value of stake body is small; the bottom can be calculated according to axial forces. The early-warning value is taken into account in this paper.

On the basis of the fundamental principle of rigorous Janbu method,formulas are re-derived.Through modifying the flow of the method, the differential operation can be transformed to integral operation so as to avoid the derivative’s error. The example analysis indicates that the inherent cause of non-convergence is the assumption of rigorous Janbu method; the assumption about the line of thrust is unreasonable.

The problems that the horizontal static equilibrium of the slice with the sliding surface of soil arching effect is not possible in calculating the distribution of the unit earth pressure on retaining wall are presented. And according to the static equilibrium of horizontal-stratum soil in the sliding wedge, the equation of calculating the angle of failure line to horizontal are formed. Equations of calculating the unit earth pressure, the resultant earth pressure and the points of application of resultant earth pressure on retaining wall are set up. Comparison among the results calculated by formula presented here and the other methods and the experimental observations is made. It is demonstrated that the calculating results by this paper’s method have better safety and agreement with those of the experimental observations than those by the other methods.

Rainstorm could induce a mass of landslides occurrence. There was a different critical rainfall value in different regions, while the rainfall intension was larger than the value, a lot of landslide would occur, thus had been proved by many happened facts. In general, the theory of rainfall infiltration was the recharge rate was a constant when the rainfall intension was larger than the certain critical value, the more redundant rainfalls become the flow on the earth surface, it couldn’t infiltrate into the earth, as was not consonant with the fact that the more precipitation could induce the more landslide. There were a lot of fissures in the slope which had enormously contributed to the rainfall infiltration. It was simulated by finite element method that changes of transient seepage field in the slope with fissures and without fissure, and the slope stability was calculated in different depths potential slip surface via the Bishop method. It was shown that the calculation result, considering the fissures, was more consistent with the macroscopically observed facts. The fissures existing in the slope should be considered enough when the slope stability about rainfall infiltration was evaluated. Only the rainfall intensity was larger than the certain critical value, the enough rainfallfall could infiltrate into slope body along the fissures, the effect of fissures on stability would be obvious.

Based on the upper-bound approach of limit analysis and the strength reduction technique, the equation for expressing the critical state of slope stabilized by a row of piles is formulated and is employed to determine the lateral limit effective earth pressure and its corresponding critical failure surface for a given slope subjected to pore water pressure. The presence of pore water can be embodied through work terms in the energy balance equation, and water pressure is considered as an external force similar to gravity and surface tractions. Furthermore, the governing equation of deflection for stabilizing pile is built based on the obtained dimensionless lateral limit effective earth pressure, and the numerical algorithm using finite-difference method is developed to numerically solve the partial differential equation. Finally, numerical computations are made to examine the effect of pore water pressure on optimum location of pile placement and the reinforced force supplied by piles with a typical example slope.

The seismic coefficient suggested in the present Specifications for Seismic Design of Hydraulic Structures (DL5073-1997) is suitable for earth-rock dams lower than 150 meters. While at the present time, many earth-rock dams to be constructed are higher than 150 meters. Compared with low dams, high dams get less constraint from stiffness of foundation, and its natural vibrating period becomes prolonged. During the seismic response, high order naturalvibrating period gets more opportunities to coincide with the seismic predominant period, and the vibrations of high orders are easily to be activated and amplified, which result in the seismic acceleration distribution is somewhat different from low dams. With the finite element method, the seismic acceleration distribution of high earth-rock dams is analyzed. The figure of the seismic coefficient of earth-rock dams higher than 150 meters is put forward. Based on the above analysis, further research of the slope seismic stability of earth-rock dams higher than 150m is made. The conclusion is, with the decrease of the seismic coefficient in the dam body, the critical value of safety factor of the dam slope increases.

It has become a common understanding that freeze-thaw cycling is a kind of weathering process which considerably changes geotechnical properties of soils due to cryogenic actions. Therefore, the influence of freeze-thaw must be taken into account when selecting soil parameters for stability and deformation analysis of many geotechnical engineering problems in cold regions where newly exposed soil layers are bound to be submitted to freeze-thaw cycling. The changes in strength parameters (c, φ) and pre-consolidation pressure (Pc) due to freeze-thaw are investigated through testing on a frost-susceptible soil, Lanzhou loess within a wide range of dry density and temperature. The soil samples have all experienced one freeze-thaw cycle. Direct shear and 1-D compression tests are carried out on the samples before and after freeze-thaw. Testing results before and after freeze-thaw are then comparatively analyzed. It is shown that the pre-consolidation pressures and strength parameters are influenced by freeze-thaw.

The vertical earth pressure on the top of rectangular trench-buried culverts is analyzed experimentally and theoretically under the condition of non-cohesive soil. Taking account of effect of the soil masses beside culverts, a new model and formulation for calculating the earth pressure is proposed. The calculated results agreed with the experimental results. The results show that the coefficient of earth pressure decreases monotonously with the increases of the depth of soil overlying culverts if trench width equals to the outer diameter of the culverts; and the coefficient increases first and decreases afterwards if trench width exceeds the outer diameter of the culverts; the coefficient is the maximum as the depth of burial becomes the height of the initial plane of equal settlement. The coefficient and the height of the plane of equal settlement increase in hyperbola with increasing ratio of trench width to culvert width. The trench width that is 7 times the diameter of the culverts is approximately the critical width between trench-buried culverts and positive-buried culverts. The coefficient increases with the increasing angle of internal friction of the soil. The height of plane of equal settlement decreases as the depth of soil overlying culverts increases. The height of plane of equal settlement decreases as the depth of soil overlying culverts increases.

The successful key, the prediction of displacement time series of landslide based on support vector machines (SVM), is designing or choosing a appropriate kernel function. The characters of classical displacement time series of landslide are analyzed; and some general properties of Mercer kernels are discussed. And we use a number of closure properties to create optimal kernels for the SVM prediction of landslide displacement data. The efficiencies of designed kernels are tested by predicting three groups of displacement time series. All experimental results show LPG and MPG kernels outperform the standard kernels, and the LPG kernel is of efficient about the regression and prediction of complex displacement time series. The MPG kernel is appropriate for simple deformation datasets with obvious laws. Furthermore, some good experiences are obtained about kernel parameters choice by investigating interconnection between different parameters and models learn performance.

Vacuum preloading may endanger the surrounding buildings and buried pipes. From the variation of water table, lateral displacement and settlement out of the reinforcing area, the influence range of vacuum-surcharge preloading is 12.5 m outside the edge of treated area. To reduce the deformation of surrounding soil, three different control methods such as cement mixed piles wall, stress release trench and underpinned root piles are studied experimentally. Inward lateral displacements chiefly occur at 6 m below the ground. The maximum lateral displacements outside the cement mixed piles wall are 1/3 of the inside one and after loading the outside deformation is far less than the inside one. The maximum lateral displacements inside the stress release trench are 3/10 of those inside the piles; and the maximum lateral displacements outside the trench are 3/8 of those outside the piles. As far as reducing the lateral displacements at vacuum preloading stage in this experiment, the stress release trench is much better than the cement mixed piles wall; but at the vacuum-surcharge preloading stage, outward displacement of the deep subsoil near the trench is much more obvious. The settlement of underpinned foundation of iron tower by root piles is very small.

The in-situ test on negative skin friction of piles in high-piled wharf is one part of Shanghai Yangshan Deep Water Port Engineering. For piles in link-banked structure of high-piled wharf, rubble-mound may cause negative skin friction on piles. Based on data from in-situ tests on piles (two supporting piles and one free-headed pile), basic laws of pile internal force have been obtained. During rubble-mounting negative skin friction mainly comes from the pile segment which is surrounded by dumped rubble. Meanwhile, rubble-mount as surcharge load induces consolidation of soft sub-soils. Negative skin friction on piles also exists under dumped rubble layer because of the relative displacement between the pile and the sub-soil. The negative friction is also greatly influenced by the load on base slab. The distribution character of negative skin friction and the formula for calculating negative skin friction in layered soils proposed in this paper provide some useful data for pile design; especially, for dumping rubble construction in one side underwater, and for selecting measures to reduce negative skin friction.

When using numerical simulation methods to solve the stability of slope, the strength reduction method is in common use. But this method is not validated and generalized because there are many factors which affect the precision of results. Using the fast Lagrangian analysis of continua (FLAC) according to the comparison of results we can find out the influences of boundary range and density of the grid in the analysis of slope stability. Especially we get rid of the bondage that is the boundary range should be large enough which is the modeling principle. The results prove the reliability of the conclusions.

Some problems that conceptions of two types of parameters including modulus in tension and compression with corresponding viscosity coefficient and shear modulus with corresponding viscosity coefficient are unclear or these two types of parameters are translated irrationally，are occured in the application of back and positive analysis for viscoelastic model. Due to solve these problems，the conceptual difference of these two types of parameters is analysed firstly. Then，translated relations between these two types of parameters (generalized Kelvin model for hypothesis of constant volume modulus) are established theoretically. Using these translated relations in viscoelastic model for rock and soil，the numerical experiment，discussing these problems mentioned above for back and positive analysis，indicates the internal reason occurring these problems mentioned above and presents the feasibility method solving these problems. At the same time, the thinking solving these problems mentioned above is adopted to the condition of other hypothesis for viscoelastic model.

1158 landslides induced by rainfall during the period of 1973 to 2002 in Jiangxi Province are analyzed from the terms of lithology and slope aspect. And the relationship between probability of the rainfall-induced landslides and rainfall is analyzed statistically. It is concluded that: (1) Landslides in Jiangxi Province occurred mostly in 1998 and 2002, or in May to October, especially in June; (2) About 64 % landslides occurred on the slope face to South, but the rainfall influence to the landslide with different slope aspect is almost the same. And the only difference is that the landslides face to North need about 3 % more excitation or effective rainfall than the landslides face to South; (3) 6 days accumulative rainfall ,14 days effective rainfall(the coefficient of the effective rainfall =0.82), 3 days accumulative rainfall and 9 days accumulative rainfall is the most relative kind of rainfall respectively to the landslides in metamorphite, magmatite, carbonatite and fragmentary rock;(4)The lagged time of landslides is discussed based on the classification of different lithology . (4) About 80 % landslide occurred just on the storm day ,and 12 %－14 % landslides occurred in metamorphite, magmatite and fragmental rock after the storm, about 22 % landslides occurred in carbonatite after the storm. And the lagged time is almost 1 to 3 days; the landslides in carbonatite have relative shorter lagged time than the others, which is due to the penetrability of the slides, degree and speed of rock and soil strength weakening.

model comparison tests of SMW engineering method and shaped steel exterior-protected construction are proceeded by loading on active side to simulate unloading on excavation side. Test results show that: shaped steel and cement soil of SMW engineering method can be a whole body and perform jointly compared with single shaped steel exterior-protected construction because of cement soil enclosing of shaped steel, so that stiffness of shaped steel is increased; and horizontal displacement can be decreased effectively. Internal force of SMW is less than that of single shaped steel exterior-protected construction obviously because of cement soil; this is accordant with actual measurement of engineering. Performance character and interacting mechanism of SMW are discussed from various angles.

The toe-shooting method has been widely used to build nearshore groynes in China. The proper method for analyzing the slope stability of this kind of groyne is however not found at present. Based on the limit equilibrium method a typical groyne located in a deep silt and soft soil mass aside is first analyzed. A new method calculating the factor of safety is then proposed for the slope stability of these groynes. Finally, the method presented and other four common methods are used to analyze the slope stability of a practical groyne. It is shown that the proposed method for slope stability of this groyne can give the more realistic factor of safety than the other four common methods.

The water level falling of the reservoir produces saturated-unsaturated unsteady seepage in the slope. The unsteady seepage is one of the important reasons of slope instability. To know the influences of unsteady seepage on the slope stability, consolidation equation of solid and liquid phase porous media is derived, which takes the coupling role of seepage and deformation into consideration. On this basis, slope stability factor is calculated by finite element shear strength reduction method; and a set of unified finite element method is adopted for seepage, deformation and stability analysis. The influences of permeability of soil and falling of water level of the slope on stability factor of landslide in case of sharp falling of reservoir level are analyzed through case dies. The calculation results indicate that the theory and method proposed are feasible and effective. An efficient tool to analyze the slope stability problem under saturated-unsaturated unsteady seepage is given.

The engineering geological drilling exploration for the Jinduicheng tailings dam area is carried out to serve the heightening design of enlarging its volume. According to the permeability, physico-mechanical parameters of the two zones, the tailing sand and the rockfill of initial dam and the distribution of saturation surface under the heightening design plan are determined by the inverse analysis based on the drilling exploration result. Combined with the heightening design plan, the applied numerical method is the finite element method; and the software is EFES-3D based on the effective stress. It can numerical simulate both the stress-strain field and safety factor of the slope under the heightening design plan, and be concluded that the dam slope up rush and the safety factor of slope reducing under the upstream heightening design plan, which is not profitable for dam stability and management. Also the measures of drain pipes in the design of enlarging the volume are proposed.

Recently, many countries have highlighted the single-column offshore-wind structures; and Germany has formulated the plan to research huge single-column offshore-wind energy structures. Based on the plan, Germany sets up new type lab model and uses Fe program to simulate single-column offshore-wind energy structures. All of them are introduced in the paper. The pore water pressure in sandy soil is researched when the single-column is under cyclic load. And then the pore water pressure in different permeabileties of soil and under cyclic load with different frequencies are analyzed. It is concluded that the existence and size of the pore water pressure is influenced by itself and circumstance situation. The research results can be used to research huge single-column offshore-wind energy structures in Germany.