Based on previous study, the authors deduced the three-dimensional relationship between micro-contact force and the macro-stress on convex polyhedron. Meanwhile the authors proposed the way dealt with the structured soils through investigating the properties of soil fabric and bonding between soil granulae. Following the conception of binary medium of structured soils presented by SHEN Zhu-jiang, this paper presents three models of failure of bonding under macro-stress and provides the equation for iterative calculation to derive the macro-compliance tensor. As an example, the structured soil behavior with the isotropic bonding and isotropic fabric under the isotropic loading has been studied and the closed-form solution of the failure development and the stress relationship has been derived. The investigations show that the failure of structured soils is caused by both of micro-shearing and micro-tension, which is corresponding with the real experimental study.

To study the nonlinear fracture mechanical characters of undisturbed frozen soils, the fracture TestⅠand TestⅡ based on the method of undisturbed frozen soils’ field test before have been done. According to the variational rules of heave quantities, the frozen depths and time at different depths, the temperatures were controlled strictly when the specimens were being made and tested. Then the relationship between the specimen displacement of force point and the force has been measured by using the dynamic data acquisition system; and the corresponding nonlinear parameters have been calculated. A new method, which can use nonlinear revision factor to predict fracture toughness of undisturbed frozen soils, has been proposed. Moreover, using present method, nonlinear fracture toughness of TestⅠ and Test Ⅱstraight crack loading and unloading specimens has been also computed. Numerical comparison shows that present results agree well with those computed from rock fracture mechanics. Therefore, this new method could be used to test and revise nonlinear fracture toughness of undisturbed frozen soils.

Shallow biogenetic gassy sand is one of special unsaturated soil. Because of containing closed biogenetic gas, whose existence has great influence on the engineering property of sand, the sandy soil has special engineering characteristic from other common ones. In this paper, the initial judgment is drawn on whether sand contains biogenetic gas, and then the in-situ and laboratory tests are done to compare the bearing capacities of sand before and after gas release. It is found that with avoiding seepage failure happening, the slow release of biogenetic gas can increase the bearing capacity of sand, which will be good for the stability of upper buildings.

Because of the complicities in the detailed structures and the mechanical behaviours, it is difficult to completely simulate the bolted discontinuous rock with the conventional numerical model. Based on the former works of the authors, the composite element method (CEM) is further developed to study bolted discontinuous rock. The mesh can be generated without taking account of the existence of bolts and discontinuities in this study. The composite elements of bolted rock, discontinuous rock and bolted discontinuous rock can be defined and their CEM model can be formulated respectively. Some sub-elements covering the different materials are also defined to simulate the detailed structures in bolted discontinuous rock. The algorithm of bolted discontinuous rock by composite element method is illustrated and the way to implement this algorithm is introduced. The comparison of the numerical examples between FEM and CEM shows the robustness of the proposed method, and the advantage of CEM over, i.e. very convenient for the pre-process.

Some dynamic characteristics such as shear modulus, damping, strength, pore water pressure and liquefaction are studies by dynamic triaxial tests on saturated compacted loess under different consolidation stress conditions. It is indicated that from test results ,the relation between dynamic stress and strain can be fitted with hyperbola, power correlations between its two parameters containing the maximum dynamic shear modulus and the maximum dynamic shear stress and consolidation axial stress are obtained and normalized under different consolidation stress conditions. Damping ratio is almost independent of consolidation confining stress and consolidation ratio. Dynamic shear stress ratio increases with the increase of consolidation ratio, it decreases with the increase of consolidation confining stress. Relation between dynamic pore water pressure ratio and cyclic number ratio is dependent on consolidation confining pressure and consolidation ratio as well as dynamic stress. Relation between ratio of dynamic pore water pressure and cyclic number ratio at vibrating process and failure is only dependent on consolidation confining stress ,which is independent on consolidation confining stress and dynamic stress ,and can be fitted by power function. The saturated compacted loess can produce liquefaction when failure cyclic number is larger than 30 under isotropic consolidation stress condition and can not produce liquefaction under anisotropic consolidation stress condition.

The displacements of two selected international landslide cases are calculated by two-dimensional program of UDEC and Newmark method, respectively. Comparison between the calculating results and the field values of earthquake induced displacements shows that the displacements calculated by Newmark method are lower than the field values and the displacements simulated by UDEC are close to the field values. Then, the influences of height and angle of bedding slope and angle of interface on displacement characteristics of bedding slopes under earthquake are analyzed. It is reported that the displacement doesn’t monotonously increase with the increasing of H (height of bedding slope). It reaches max when H is about 100 m and then decreases with the increasing of H. And when H is above 200m, its decreasing rate is small. It is also suggested that the displacement increases with the increasing of the angle of bedding slope. As well, the displacement increases with the increasing of β (angle of interface), and its increasing rate tended to obviously increase with the increasing of β at the condition of β larger than the friction angle of rock joint.

The diversion tunnel outlet slope at the left bank of the Jinping-I Hydropower Project is naturally steep, with deep fractures, compressive fracture zones between layered strata, and release fractures oriented parallel to slope surface heavily developed. After excavation of the rock mass near the slope toe that maintains the stability of the slope, negative effects will occur on the stability of the cut slope and the upper rock mass developed with deep fractures. Based on an elastoplastic constitutive model of rock mass reinforced with rock bolts and cables, numerical simulations are performed by elastoplastic FEM to evaluate the stability of the slope during slope excavation, reinforcement and under seismic loading, and to evaluate the effectiveness of a suggested construction procedure of “anchoring before excavation and anchoring immediately after excavation”. Finally, several suggestions that may be helpful to construction of the slope, are presented.

Shear beam model for interface failure was used for analyzing the fault rockburst occurrence. To analyze fault rockburst without considering the elasticity of the fault, the law of shear beam displacement and stress distributions, tearing crack length and critical load when fault rockburst occurred were obtained. The relation among tearing crack length, critical load and various kinds of mechanical parameters was analyzed. The results obtained show that if mining depth is large, and if the shear elastic modulus of the shear beam is low and thickness of the shear beam is large, and if shear softening ratio of faulted zone is large and thickness, coefficient of sliding friction, shear stress peak strength of faulted zone is low, then fault rockburst is easy to occur. These parameters of mining depth and the shear elastic modulus of the shear beam and shear softening ratio, shear stress peak strength, thickness of faulted zone have a more large influence on the fault rockburst occurrence. The theoretical foundation for fault rockburst prediction and prevention was proposed.

Characters of surface subsidence have been researched by means of large solid experiment frame in mining horizontal section top coal caving in steep seams. It is discovered that the subsidence of steep seams is different from subsidence of gently inclined seams. The holes which appear initially will be transfixed and form surface collapse pit in process of mining steep seams. Collapse degree of rocks near roof is larger than rocks near bottom. The surface subsidence has repeating characters; and collapse rock is a declined step distribution as mining inferior sections. Collapse pit with deep groove will be formed at last.

The two different methods for estimating the correlation distance of soil layers are compared and studied based on the random field theory. The reason why difference correlation distances may be estimated by different methods is explained. The results obtained by using both methods respectively are proved to be approximately the same if the number of samples is large enough. The correlation function method is improved in order to make the curve fitting and parameters determination easily. The conclusion is validated through calculation of some investigation data of practical engineering.

Thrust force is an important construction parameter during tunnel excavation with shield machine. It not only determines the advance rate but also influences other working parameters, such as cutter torque and rotation speed, etc. But so far, the research on thrust force, especially on frictional force between soil and shield tube, still does not go into enough depth. Therefore, a special model test scheme on tunnel excavation with earth pressure balance(EPB) shield machine is designed by the authors; while the silt sandy ground in Shanghai area is taken as prototype, then different parameters of shield machine and ground properties can be combined for testing. Based on the test results, studies are carried out to discover the variation law of thrust force, the mechanism of friction between soil and shield tube and its influence factors. Furthermore, a calculation formula of thrust force is deduced.

Reflection of inclined incident elastic waves at a fliud/fliud saturated poroelastic solid interface is studied. Attention is focused on the influence of the sealed-pore boundary on the reflection coefficient predicted by BISQ model. The results are also compared with those based on Biot theory. The study shows that the effect of boundary condition on the reflection coefficient is noticeable based on BISQ model.

The working mechanism of reinforced soil-cement mixing diaphragm wall has been analyzed. It is pointed out that the strength of soil-cement must be enough in the reinforced soil-cement mixing diaphragm wall. The strength of soil-cement between the shaped steels must be enough not only to load the shear stress, but also to load inclined section stress along the level. Although the contribution of soil-cement to vertical bending rigidity of the wall is too little to neglect, the compression strength of soil-cement must be enough to be kept integrity and water stop. On the other hand, the side restriction of soil-cement to shaped steels must be strong enough and be kept integrity to keep integral stability of shaped steels.

The digging resistance of soil can be reduced greatly if the bucket is vibrating when the hydraulic excavator is working. The resistance-reducing mechanism of vibratory excavation is researched theoretically. The soil cutting experiment indicates that the interior friction angle and the shear intensity of soil is reduced; and the maximum principal stress is decreased due to the vibration load; it induces the decrease of digging resistance. The comparison simulation experiment research on the failure process of soil under static load and vibratory load has been carried out. The result shows that soil intensity is obviously decreased under vibratory load and destroyed earlier than that of static load. The digging resistance reduced 50 % under vibratory excavation when tracking the load in X-direction.

Wetting deformation of coarse grained soil is an important problem in earth dam design; but it is not solved well so far. The wetting deformation tests under various stress levels are carried out on a coarse grained soil; and the wetting deformations and curves of stress-axial strain-volume strain are obtained. The test results and analyses indicate that; the wetting deformation of the coarse grained soil is varied with cell pressure and wetting stress level; the ratio of wetting volume strain versus wetting axial strain is decreasing with the wetting stress level increasing; the wetted sample behaviour may be elacstic first elastoplastic after, while new load is forced on the sample; the method of single line for calculating wetting deformation is better than double lines. At the same time, a new method of improved double lines for calculating wetting deformation is proposed; the maximum wetting stress level is defined and used to explain the test results. The results may be significant to farther research on wetting deformation.

In order to achieve intelligent blasting and reduce the blast-induced adverse influences, the prediction of rock damage and its distribution scope through numerical simulation is of importance in engineering. Thereinto, the reasonable damage constitutive model for rock is crucial. By assuming that the rock mass is an isotropic and continuous material with pre-existing random initial microcracks, an available rock tensile damage evolution equation considering time effect is coupled with the bi-linear elastoplastic constitutive model. Then they are succinctly incorporated into the transient dynamic code, LS-DYNA, via its user defined subroutine. In addition, the erosion algorithm in LS-DYNA is employed. The tensile damage and blasting crater near the free-surface of semi-infinite rock mass is numerically simulated; and the numerical results are satisfactory. This method presented herein has some reference value in rock blasting.

FLAC3D is applied to analyze the stability and the ultimate bearing capacity of upper plate of karst cave under the loading of rectangular spread foundation; and two typical types of rock mass are studied. The ultimate bearing capacity of upper plate of karst cave in various engineering conditions are presented by analyzing the characteristics of rock stress and displacement and the whole evolvement process of plastic zones in the upper plate. The results show that the ultimate bearing capacity increases with the increasing of the thickness of upper plate and decreases with the increasing of the width of karst cave. In the same conditions, the ultimate bearing capacity of rock IV is only one third of rock III.

Initial stress is one of the important factors affecting the stability of geotechnical engineering. How to reasonably simulate the initial stress field is always an urgent problem in rock mass mechanics. Based on the 3-D stress measurements of a certain large-scale hydropower station construction site, the initial stress field of rock masses is analyzed by finite element method, The numerical model is established according to the topographical characters and real geometry of large structures and faults located at the site. The stress field at any point is thought to be composed of gravitational and tectonic stress components, while the gravitational stress component is assumed to be known as the results calculated by finite element method. When fitting the total tectonic stress component at the measurement points, unit normal displacement is applied to the model boundaries and the response is computed at the location of the measurement points in the model. In order to reproduce the measured stress at the measurement point, a linear regression expression is used to calculate the proportions of each unit response tensor. In addition, infinite element is also attempted to be introduced into the model of initial stress field analysis to meet the requirement of zeros displacement values on the boundaries; the preferable results obtained demonstrate that this method is powerful and feasible.

The structure of the seabed silty soil in the Yellow River delta is understood by its properties and piping phenomena under cyclic loads. Applying breakage mechanics, a double-medium model composed of structural lumps and structural bands is established. During the process of increase loads, decrease loads and liquefaction seepage, deformation and breakage in the structural bands and exchange of effective stress and pore water pressure are qualitatively researched. Qualitative analysis indicates that the strength of consolidation should be increased within the depth of liquefaction, which accords with the result of test. Experiment shows that the different phenomena of liquefaction seepage are regarded as cause of existing piping in structural bands and water discharge in structural lumps with the double-medium modeling.

A series of tests were conducted for the unsaturated expansive soil using three-dimensional swell-shrinking device. The three-dimensional swell-shrinking characteristics of remolded expansive soils was studied. According to the test results, three-dimensional swelling pressures are unequal. The lateral swelling pressure is smaller than vertical swelling pressure. The swelling pressure of remolded expansive soil is decreasing with wet-dry cycles. And a small strain could bring obvious decreasing of swelling pressure. The logarithmic relation between lateral pressure and strain is proposed. A formula of vertical swelling pressure with initial water content and dry density is given.

Based on elastic theory and reasonable assumption, the control differential equations have been put forward by adopting the load-transfer function method in order to research the load transfer mechanism of composite foundation of rigid piles with cap, including relations among pile settlement and its axial stress, vertical displacement of soil under pile cap and vertical stress of it, vertical displacement of soil besides pile cap and vertical stress of it, the friction force of pile-side, the soil friction force of the edge of pile cap and load level, depth in rigid pile with cap composite foundation. The corresponding analytical formulas have also been derived by using approximate solution method of differential equation. The calculation results can image basically the mechanical behavior rules of the load transfer for rigid pile with cap composite foundation according to the method proposed, using directly the relation of load-settlement of pile tests as known condition.

Solidifying saline soil in inshore with different quantities of salt using lime, which causes the microstructure indices and strength of saline soil change obviously and increase greatly. It has been proved that strength has good correlation with microstructure indices with the help of multivariate stepwise regression method; and the five indices, including particle granularity fractal, particle orientation fractal, particle diameter, particle oblate degree, and particle area ratio, are the significant indices effected on the strength of solidified saline soil in inshore with lime. According to calculation results of microstructure indices, its fractal, and strength, solidifying mechanism of lime-saline soil can be certified from another aspect.

A scattering wave function satisfying zero-stress condition on horizontal surface is constructed by using the functions of complex variable and multi-polar coordinate system. The scattering of SH-wave with arbitrary incident angle by a subsurface cavity of arbitrary shape in half space is studied together with its influence on ground motion. Numerical results of the ground motion on subsurface cavity are provided. The effects of incident wavelength, incident angle, shape of cavity and buried depth on ground motion are analyzed quantitatively. The research indicates that great interaction exists between the subsurface cavity and the horizontal surface, which will bring about great influence on ground motion. Therefore enough importance must be attached to the existing of subsurface cavity while finishing seismic design for building.

The calculated value of safety factor of a slope directly determines the design of slope engineering. However, the limit equilibrium method can not yield a single value of safety factor; thus the study of multiple solution of safety factor helps in justifying the reasonableness of the computation results and selecting the range of possible values of safety factor. The initial distribution of normal stresses over the slip surface is assumed, which is then modified by a Lagrangian function involving three parameters to satisfy the complete equilibrium conditions of the sliding body. Solving the equilibrium equations yields values of the three parameters associated with a series of prescribed safety factors, and the reasonable range of safety factor of a slope is justified according the reasonableness of the normal stress distribution over the slip surface. Example studies show that the reasonable range of safety factor for a circular slip surface is within 5 %; however, for non-circular slip surfaces, this range would be as large as 15 %.

The reinforcement principle and some properties of soilbags are introduced. Some practical application cases of soilbags in Japan, such as the reinforcement of building and road foundations, the construction of retaining wall and debris-diversion embankment, are presented. The reinforcement of soilbags is contributed by a tensile force, which thereafter induced an apparent cohesion. The tensile force is produced due to the extension of the perimeter of soilbag under the application of external force.

Electric current flows through clayey soils by the conduction of void water, electric double layer and clay minerals. The electrical characteristics of clay are discussed at first. Based on the hypothesis that there are three conductance pathways in unsaturated clay, and aiming at the deficiency of the existing models of unsaturated clayey soil, the electrical resistivity model of unsaturated clayey soil is studied. The main factors which affect the electrical resistivity of soils are summarized and analyzed. Through the laboratory tests, the characteristics of the influences of water content, the resistivity of pore fluid, temperature and porosity on the electrical resistivity of Hefei expansive soil are studied.

In contrast with the symmetry that is seen beneath footings on level ground, results from theoretical analyses and physical models near an excavation or on slope show that the failure zones are asymmetric. This paper studies on the failure zones of c-φ soils near excavations under vertical ultimate load, and the numerical simulating results obtained by using FLAC-3D approximate to J.Graham's failure zones using the method of stress characteristics in cohesionless slope. Finally, Nγq from numerical simulating technique are compared with large-scale experimental and theoretical values of Nγq in cohesionless slope under various construction conditions; and a brief assessment using numerical simulating method of superposition assumption indicated that the assumption is conservative.

The stability of boundary pillar can be found across in open pit and underground mine shifting. In this paper, based on the conditions of Dabaoshan Mine which is a open pit and underground mine, the stabilities of boundary pillar are calculated and analysed by using the method of numerical simulation. It is found that the tensile stress of the roof of mine-out areas is the main factor of the stabilities of boundary pillar. The boundary pillar’s safety thickness is calculated by the method of numerical simulation and have compared and analysed with other results which are calculated by five representative ways. Through summing up the calculation results by summation normalization method and approximating the result by polynomial numerical approximation method, the relationship between the span of mine-out areas and the boundary pillar’s safety thickness has been established. It can be used to prove , supplement for the stability of boundary pillar of open pit and underground mine and can guide the design of the boundary pillar’s safety thickness. This will be of great significances to instruct the safety production of open pit and underground mine.

The analysis of reinforced soil is regarded as two stages: viscoelastic stage and visco-elastoplastic stage. The creep performance of geosynthetics is considered. Elastic strain of reinforced soil, stress of geosynthetics and horizontal microstress of soil in viscoelastic stage are given. Stress relaxation appears weakening by negative index as the time increasing. At the same time strain of geosynthetics is increasing. The time and deformation corresponding to initiation of the plastic stage are given. Stress in the reinforcement remains constant in visco-elastoplastic stage. But the deformation remains increasing due to creep. Therefore the stress and strain in reinforced soil can be analyzed in different cases history. Then severe consequence due of strength and stability weakening and deformation increasing, can be reduced.

During double-o-tube DOT tunnel construction, rolling will inevitably occur due to the following reasons: different subsoil condition; manufacturing errors of machine; different pull forces at the two sides; effect of assembled segments; loss of grouts; and operation problems. Several countermeasures to correct rolling have been proposed. Loading using lead block at the elevated side is the most easy and economic method. In engineering practice, the weight of loading is determined by the experience of operating workers and/or through the observation of returned rolling angle. There is no prediction method before loading applying. Moreover, loading correction will also cause additional movement of surrounding ground. This paper analyzes the weight-correcting angle relation and deformation around DOT shield by employing FEM. For the allowable angle of 0.6 degree, the applied load should be 350 kN. Correcting 0.6 degree causes about 85 mm of additional surface settlement. These results can give a guide to the construction management.

Based on the successful experience of Jinmao Building of 88-storey in Shanghai, this paper attempts to predict the behavior of piled raft foundation for Shanghai World Financial Center of 101-storey, such as， the bearing capacity of pile and its increase with time, load-sharing between piles and raft, thickness of raft, settlement and theory of design of piled raft foundation. Finally, some comments on these two buildings have been made for helping the study of theory of super-long pile foundation design for super-tall building in Shanghai.

The relation between wedge body and the model of cutting slope is shown. Then analytical method of relaxation zone for cutting homogeneous slope by elastic theory is given. The stress field of cutting slope can be analyzed by elastic wedge body theory. On the basis of elastic plane-strain theory, the relaxation zone related to one safety factor can be calculated according to Mohr-Coulomb law and single tension intensity principle that are both related to the same safety factor after three-dimensional stress field of the cutting slope is got. After every cutting step is completed during excavating the whole slope, its corresponding relaxation zone can be calculated. The main calculation procedure of relaxation zone for cutting slope is given. After every cutting step is completed during excavating a slope step by step, the corresponding relaxation zone for the whole slope can be calculated by main discussing stress field of the slope after last step, additional value of stress field of the cutting slope on current step and local relaxation zone for the slope related to current step. Finally, explicit calculation procedure of analyzing relaxation zone for cutting slope by elastic wedge body theory and strength criteria of slope material is given in detail by an example.

It is evident that the rainfall has a remarkable effect on slope stability. When the highly weathered soft rock is used for high-filled embankment slope ,compacting factor directly effects on permeability and intensity of embankment soil . Transient seepage due to the rainstorm infiltration is computed using the finite element method. The computed transient pore water pressures are then used for limit equilibrium analyses of landslides. And effects of matrix suction on shear strength of unsaturated soils are considered. Effects of the compacting factor and intensity and duration of rainfall events are discussed. The results show that when rainfall intensity reaches 200 mm/d, the slope is instable. And the compacting factor of strong weathered soft rock used for high-filled embankment should not be less than 90 %; which is provided scientific basis for the treatment of high-filled embankment slopes.

The stability of a twin-tube highway tunnel is analyzed using improved discontinuous deformation analysis (DDA) method. By employing advancing front method, the triangular DDA blocks are automatically generated in the computational area. In this process, numerous artificial joints whose strength is higher than that of real joints come into being. In addition，the reinforcing effect of prestressed bolt on the surrounding rock is also taken into account. The numerical results are compared with the measured data, and they show pretty good agreement; therefore, it is shown that the improved DDA method is capable of analyzing stability of underground tunnels.

Based on deeply analyzing the closure effect and stress dispersion of crust, a critical edge pressure formula of soft clay foundation considering the two effects is derived. At the same time, through the analysis about the generation of the closure effect, it is pointed out that the traditional method in elastic mechanics couldn’t consider the closure effect of the curst .

Direct shear test is an effective approach for studying rock masses containing discontinuous joints; through the test, both failure models of joints and of rock bridge, when one of the principal stresses is tensile, can be simulated. Based on this test, failure mechanism has been widely researched; and shear strength criteria have been put forward, such as Jennings method, Lajtai rock theory, shear theory in fracture mechanics, combined failure theory of tensile and shear. However, the failure mechanism is not fully clear, and some parameters in shear strength criteria, for examples, compression transferring coefficient and shear transferring coefficient of rock joints, fundamental shear strength and angle of internal friction of rock bridges, etc. are still uncertain. Closing constitutive relation and shearing constitutive relation of rock masses containing coplanar discontinuous joints, as well as maximum failure strength of rock masses containing noncoplanar discontinuous joints need deeper research. Direct shear testing machine with servo system, static strain tester, acoustic emission technique, nondestructive testing technique, etc. will be greatly helpful to further research on rock masses containing discontinuous joints.

The landslide forecasting study is one of the hot problems in landslide research. Based on the actual observation data, the exponential smoothing and nonlinear regression analysis are integrated. According to the criterions of displacement and displacement velocity, the dynamic track prediction about the slippage time of landslide is introduced. In light of the pratical landslide conditions, a model was established for the special displacement of some observation points; and the prediction based on this model was obtained with high accuracy. Therefore, the method can be used in practical engineering.

Pore-scale network model represents the genuine pores and throats with simplified geometry objects, to analyze the flow in which is of great importance. Firstly the finite element method is used to solve the velocity field which is then used to calculate hydraulic conductance. The relation between hydraulic conductance and shape factor is researched. As for the single phase flow, the result shows that the hydraulic conductance is nearly linear to shape factor. While with respect to two phase flow, it also changes with half corner angle and oil-water contact angle.

Adopting the field piling test, laboratory test of model pile and engineering examples of field piling, the principle of distribution of tensile stress in pile body is discussed by the introduction and analysis of dynamic measurement of sixteen piles. The results show that the maximum tensile stress always occurs at the top of pile, especially when pile end is embedded into the soft soil; the maximum tensile stress is located at 1/4l (l is pile length) to the top during the beginning of piling, which leads to occur transverse cracks which are perpendicular to axis of pile and the rupture of pile body. The results also show that the disk-spring pile cap can decrease hammer tensile stress, diminish the phenomenon of over-tensile stress when piling aided by conventional pile cap and make measured stress below allowable one (below 5 MPa which is considering effective method to prevent pile body from rupture).

Three representative attributes about strata to affect the vertical bearing capacity of piles are selected and transformed between their quantitative and qualitative description. A new fuzzy method of calculating similarity degree of strata along piles, derived from fuzzy theory, is then proposed and validated in practice. Its applications prove that the calculation model is rational and effective.

Based on the summarization that design theory of reliability is based on bearing capacity wholly, a new concept of reliability design based on settlement aiming at great super-long pile group is presented. Compression of pile body and stab deformation is considered in the settlement calculating model. After discussion about distribution regularity of calculating parameters, index of reliability is calculated by Monte Carlo method. An example shows that index of reliability would decrease with load level increasing; and it would increase with acceptable settlement increasing. But increase trend becomes slower.

Considering spatial mutual interaction and deformations among ring beam, middle beams, row of piles, braces and foundation soil in the deep excavation structure, the 3-D finite element analysis model is set up based on the mutual deformation theory; and specific method is settled to calculate the equivalent foundation stiffness and earth pressure. By analyzing an excavation case, the distribution rules of the inner forces, the deformations and earth pressures in the row of piles structure with ring beam are analyzed; and the results calculated with 3-D model and 2-D model are compared. Therefore, the reasonableness of calculating model and the necessity of 3-D analysis are verified.

In light of the randomness and fuzzy characteristic of EPBS ‘constructing risk, a fuzzy synthetic evaluation model is brought forward to study it; in the model, the risk’s weight is calculated by the analytic hierarchy process; and the membership degree to the risk level is calculated by trapezoidal membership function; then the total risk can be calculated by fuzzy calculating the weight and the membership degree; at last, a case study is done on Metro 8 in Shanghai which is constructed by EPBS; the consequence is coincidence with the reality.

The construction sequences of a diaphragm wall panel are simulated by the three-dimensional finite difference method. Ground responses including stress state and deformation of the surrounding ground adjacent to the excavated trench, are studied. Furthermore, the comparison between computed results and field measurements shows that the variation law is quite similar; while the variation of numerical data is a little greater than that of the measurements, especially around the toe of the trench. It can be concluded that this method can simulate the construction process of diaphragm wall well.

Taking settlement data of 69m high embankment of an expressway as research sample, using GM (1,1) grey model which has been amended by heterogeneous fill and non-equal step settlement prediction time, and compared with the prediction results of growth curve model, it is demonstrated that these two models can predict the final settlement of high embankment better; and the grey prediction model is better predictable the non-homogeneous deformation of high embankment than the growth curve prediction model. Simultaneously, it is recognized that the prediction results of this grey model are better tallied with the settlement deformation tendency of high embankment, and can do the next work of researching, popularizing and utilization.