Based on the equations of coupled heat-moisture anisothermal flow and the behaviors of stress-strain of unsaturated soil, an interaction model of atmosphere-unsaturated soil is established with the boundaries of actual evaporation and vegetation transpiration. The influence of climatic evaporation and vegetation transpiration on the suction and deformation of soil surface are analyzed by the interaction model. It is shown that the major governing factor for the suction and deformation of soil surface is outer climatic condition where solar net radiation and wind velocity are the most contribution, while the internal hydraulic and thermal parameters of soil property play a less role in the estimation of evaporation. With the cover of vegetation, the behavior of suction depends on the leaf area index (LAI), while the magnitude of total evaporation and transpiration determines the deformation of soil surface.

Lightweight sand-EPS beads soil (LSES) is a novel lightweight geomaterial to improve soft ground by reducing vertical pressure on ground and improving the bearing capacity of ground. Because LSES is mainly used as subsoil, its deformation characteristics under dynamic load is worth to study. Based on laboratory cyclic triaxial test data, the effects of confining pressure, cement content, EPS content and number of loading cycles on the dynamic deformation characteristics of LSES are discussed. Under low confining pressure(?c＝50 kPa), LSES shows linear dynamic stress-strain relationship similar with that of EPS block; while under relatively high confining pressure (σc＝100,150 kPa), its fitting dynamic stress-strain curve is hyperbolic type. Under given strain, the dynamic secant elastic modulus (Esec) of LSES increases with increasing confining pressure and cement content while decreases with increasing number of loading cycles; and Esec? εd curve is more smooth when EPS content increases.

Suction caissons have been widely used in offshore structures. Method of installation analysis is very important research subject. This paper provides the characteristic of the seepage field of the foundation during suction installation, and gives relationship between the ratio of the suction descending on the inside wall to the overall suction versus penetration depth-diameter ratio (?1).The pump effect on ?1 is also analyzed and evaluated. A simple and convenient calculating method of both suction caisson penetration resistance and ultimate suction in sand ground is proposed. An equation of ultimate penetration depth-diameter ratio (UPDR) calculating of suction caisson in sand is proposed. The UPDR in sand with density from loose to extremely dense is analyzed; and it is about 2.1 to 2.5 while the effort to UPDR of the deadweight of the structure and the pumping effort to UPDR are not included in it.

The dynamic response of porous elastic medium due to a harmonic load, is investigated theoretically by developing the coupling thermo-hydro-mechanical governing equations. The material of foundation, obeying Biot’s dynamic poroelastic theory, is idealized as a uniform, fully saturated poroelastic half-space stratum. The analytical solutions of stress, displacement and pore pressure are derived using the Fourier transform and Fourier inverse transform. Numerical results are obtained and used to analyze the distribution of temperature increment, stress, displacement and pore pressure under the condition of thermo-hydro-mechanical coupling. Furthermore, the influence of heat source acted on the surface of foundation on dynamic response is discussed. The stress, displacement and pore pressure is slightly decreased with the increase of temperature increment .

Based on the relations between coefficient of coulomb’s active earth pressure and internal friction angle, grading angle, slope angle, the rules between coefficient of coulomb’s active earth pressure and different parameters were analyzed. On the basis of algebraic method, a simplified solution of coefficient of Coulumb’s active earth pressure was deduced. Then the coulomb’s method and the simplified method were compared . The results show that for Coulomb solution, the maximum error of the simplified solution is less than 14 percent on the condition of 95 percent probability.

For the purpose of improving the strength and stability of soft soil, studying the effects and mechanical properties of fibre reinforced soil; the polypropylene fibre has been chosen as the reinforcement material of soft soil. Therefore, in the present investigation, fibre was randomly included in to the raw soil, lime soil (with 5 % and 8 % lime content) and cement soil (with 5% and 8% cement content) at three different mass percentages of fibre content, i.e.0.05,0.15 and 0.25 %.Twenty groups of samples were prepared at different percentages of fibre, lime and cement and were subjected to the unconfined compression test; the main objective of this investigation had been focused on the effect and strength mechanism of the soil reinforced with randomly included fibre. The test results have clearly shown that increasing the fibre content resulted in a small increase in the unconfined compressive strength of raw soil; while the inclusion of little fibre dramatically enhanced the unconfined compressive strength of lime soil and cement soil, the brittle characteristic was weakened and the stability in water was improved with the addition of fibre in lime and cement soil.

A new type of constitutive theory for granular soil, hypoplastic constitutive theory which was originated in recent 30 years, is introduced in detail. Comparing with the elastoplatic theory, the hypoplastic constitutive expression has automatically implied some basic concepts and factitious assumptions, e.g. decomposition of elastic strain and plastic strain, yield function, hardening law, plastic potential, flow rule and so on. The critical state of Gudehus-Bauer hypoplastic model is analyzed. Besides, the numerical simulation of triaxial test and cyclic shear test were illustrated and the results show that the model can grasp the main mechanical properties of granular soil, e.g. anelasticity, nonlinearity, dilatancy and so on.

Shear strength parameters have important effect on the slope stability of earth-rock dam. The Mohr failure envelope for rockfill material is obvious nonlinear particularly under the high stress linear and nonlinear shear strength theroies, value of the parameters, analysis method and safety factor criterion of nonlinear shear strength are discussed. The results of 171 sets of triaxial tests of rockfill reveal that the Duncan nonlinear strength theory is better than other models. The slope stability of 261.5 m high Nuozhadu rockfill dam is analyzed with three different shear strength criterions; the safety factors are almost equal and the positions of potential failure surfaces are also similar to each other. So the allowable safety factor base on linear criterion can be applied without any change when using nonlinear shear strength rules.

The modified Cam-Clay model is only applicable for isotropically consolidated soft clay; and it cannot describe the anisotropic stress-strain behavior of anisotropically consolidated clay. A new model, which can be adopted for anisotropically consolidated soft clay, was developed here based on the modified Cam-Clay model. An anisotropic tensor and a shape parameter were introduced in the yield surface of the model. Initial value of the anisotropic tensor was determined by the initial consolidation stress state, and its evolution was described by a rotational hardening law both depending on plastic volumetric and deviatoric strain. The shape parameter enhanced the flexibility of the yield surface. Effectiveness of the model was verified by the triaxial experimental data of kaolin clay, boston Blue clay and Otaniemi clay.

Qin-Shen Railway is the first special passenger traffic line in China. In 2002, the Ministry of Railways organized the second homologation test. The authors performed the field vibration measurements at various distances from the track. Firstly, the field measured vertical accelerations are analyzed. The attention is paid on the effect of train organization and train speed on the ground vibration. Secondly, the track is modeled as a beam on an elastic foundation; the vibration model of moving train-track-ground is constructed. Based on the theory of thin layered method (TLM), the quadratic shape function TLM is derived. The Green function of a layered half-space is obtained. At last, the ground vibration from the track is analyzed and the result is validated by means of in-situ vibration measurements. The results show that the acceleration spectrum has a maximum at the fundamental axle passage frequency. Vibration amplification is not appeared because the trains speed far less than the Ralyeigh wave velocity of the ground. The vibration acceleration is proportion to the wheel load.

Much marine soft soil lying in Tianjin inshore area, which can not be used in engineering construction. When we commonly used cement solidification agent to consolidate soil with high water content to get high consolidation strength ,we must improve the content of solidification agent, as a result the cost of engineering is higher. We use cement as main agent, and adding NaOH as assistant agent; at the same time give deeply theoretical probe and micro-structure analysis as well as verified test in foundation treatment; the results indicate that cemented soil adding NaOH has better effect on solidifying marine soft soil in Tianjin inshore area; so good to use widely.

The conception of “randomness” is so fuzzy that there are three reasonable probability models between the trace length and the diameter of discontinuities under the presupposition that the discontinuities is thin disc and the chord is the trace. The three probability models are based on the three specific but different definitions of “randomicity”: the end points of trace lines distribute evenly on the cycle; the midpoints of trace lines distribute evenly on the diameter; and the midpoints of trace lines distribute evenly within the disc. The following analysis is performed and found that the three models are all correct exactly under their corresponding presuppositions and they fit different conditions. The field condition is between the model 2 and model 3, and so a reasonable study should give consideration to these two models at the same time. A good research should firstly study the distribution of the occurrences of those outcrops, and then give the model 2 and model 3 certain weights according to the relationship of the outcrops in order to get a more reliable probability model between the trace length and the diameter of discontinuities. The results make up the defect of present theories in which only the model 2 is considered.

The split Hopkinson pressure bar test equipment was improved through adopting multi-measures. A number of dynamic compression tests and dynamic split tests were conducted with the improved apparatus for the Three Gorges granite under high strain rate. It is found that strain rate effect is obvious and dynamic compression failure of the test simples can be divided into three patterns; i.e. edge fall apart, core no damage and completely failure. The failure mechanism of the rock is discussed; and the effects of strain rate on dynamic elastic modulus and dynamic compression strength are analyzed. Finally, a dynamic failure criterion of rock based on the Hoek-Brown failure criterion is proposed.

The stationing situation's effect on error in the single domain of influence in element-free method (EFM) is studied. The idea of radius's weight has been presented. After completely numerical computing, the magnitude of influence on the accuracy of the EFM's interpolation result can be presented. The study can optimize the stationing situation of EFM, minimize the simulation errors; and the effect that the domain of influence does not depend on the number of the nodes can avoid the disadvantages of the oversize domain of influence and extra numbers of the whole interpolation nodes which is resulted from maintaining the enough interpolation nodes in single domain of influence. Then the paper also apply this theory of the stage of health in single domain for the work that take the distributing point effect on the simulation precision of MLSM which is the function EFM. The genetic algorithm is used to optimize the interpolating points; and the optimizing values are given. With an example, the relation between the optimizing value of interpolating points that have a general significance are obtained; and the density of interpolating points following with the universal principle of distribution point in element-free method.

A simple analytical solution is outlined for computing the lateral dynamic pile-pile interaction of floating pile groups in layered soil media. A dynamic Winkler model utilizing the finite-element based spring and dashpots is adopted for the effect of pile-soil interaction, combining with a transfer-matrix formulation in the case of multi-layered soils. Pile-soil-pile interaction is considered by assuming interaction between the receiving pile and the surrounding soil. It is demonstrated that the prediction of simplified method is in good agreement with rigorous numerical solutions. Attention is then given to the effect of several factors, such as pile length, tip constraint, angle between piles and soil media; and some interesting features such as “influencing pile length” are also shown.

Based on the comparison of the long-term settlement measurement data of driven pile foundation of twenty-five high rise buildings, the effects of composite of pile toe compressible layer and soil property surrounding the pile shaft on long-term settlement characteristics of driven pile foundation are studied and the results show the effects on settlement behaviors of driven pile foundation induced by thick sand layer existing in the shallow of pile shaft are very relevant to the compressive soil layers underlying the pile tip. The function of thick sand layer of pile shaft to decrease the pile foundation settlements and improve the settlement behaviors is remarkable when the compressive soil layers are mainly composed by quasi-sand layers; namely the quasi-sand ratio β more than 75 percent whereas the function is disappeared when the quasi-sand ratio β is less than 50 percent. The concept of component of compressive layers mainly functioned on the pile foundation settlement behaviors is ordinary existed in the case of the existed of thick sand layer surrounding the pile shaft. The results above mentioned are strictly related to the complex construction action induced by the construction of displacement pile.

In the whole expansive soil embankment, there exist different strength zones due to different water content and dry densitiy caused by the construction course, atmosphere and rainfall. Soil strength in the surface zones usually be strongly attenuated by the alternately wetting and drying, expanding and shrinking. But this condition usually is ignored in the embankment stability analysis. Strength zoning method takes the climate and weather into consideration. Based on the strength zoning method, expansive soil embankment stability and geogrid treatment effect analysis results show that the expansive soil embankment will easily slide in superficial layer if the embankment is constructed by full expansive soils. Stability will increase if the embankment be constructed by lime modified expansive soil, but the emergency capecity is insufficient and the incipient fault is also existence. Superficial stability will increase evidently while the resistance to overturning only increase a little if embankment being treated by geogrid, incipient fault has been effectually reduced or eradicated. All of these show the superiority of the strength zoning method for expansive soil embankment stability analysis.

A series of tests have been conducted to simulate post-liquefaction behavior of silt in a new universal triaxial torsional shear apparatus of Hohai University. Such effects on post-liquefaction of silt as soil dry density, severity of liquefaction, pre-vibration, non-regular vibration are discussed. It is found that post-liquefaction strain is composed of and . The bigger dry density is the larger and the larger shear modulus are during the stage of The more serious of liquefaction is, the larger is. But there is no difference of shear modulus during the stage of , when severity of liquefaction change. The pre-vibration and non-regular vibration affects slightly on post-liquefaction stress-strain relationship. A new post-liquefaction model of liquefied silt is proposed based on test results. And how to obtain parameters of the model is also introduced. The results predicted by the proposed method are consistent well with the experiment observation.

Determination of the blasting attenuation characteristics is of most importance for blasting design. The linear and nonlinear regression analysis methods to evaluate the parameters in the S formula and revised S formula are investigated. Based on the investigation, the concept for the residual sum of squares and nonlinear residual sum of squares (standard residual sum of squares) are proposed. The algorithm of nonlinear residual sum of squares is also introduced in detail. In accordance with the engineering case, the standard residual sum of squares is used to evaluate the deviation of vibration velocity acquired by the site monitoring and the regression analysis results by S and revised formula. It is shown that the accuracy of the nonlinear regression analysis method is significantly better than the linear regression analysis method. It is also reported the residual sum of squares and the standard residual sum of squares obtain by S formulas and revised S formula are almost similar; for this case, the two blasting attenuation formulas are available.

On the basis of analyzing and summarizing the method to calculate the ground surface settlement around the soft soil foundation pit and in the light of the deformation law of the soft soil foundation pit, the circumferencial ground surface settlement deformation of the pit is fitted in terms of exponential curves and the method is deduced to calculate the settlement deformation of the ccrcumferential ground surface of a deep foundation pit in soft soil regions that is caused by the deflection of the supporting system during excavation. Prediction is made for surface settlement through analysis and comparison of practical cases. A reliable method is put forword for the calculation of the settlement of the foundation pit projects having serious requirement on surrounding environments, which is of signifcance to enviromental protection.

Applying 2D elastoplastic numerical calculation method and under the conditions of surrounding rocks of grades Ⅲ, Ⅳand Ⅴ, the characteristics of stress and deformation of middle rock wall in parallelly laid twin tunnel are studied. The findings show that the stress and deformation of middle rock wall are adverse due to the parallel tunnel with smaller interval; and these locations are very critical for design, construction and monitoring measurements. At the same time, the effects of different buried depths and different reinforcing measures of rock wall on stress and deformation of the tunnels with small interval, are also studied, so as to provide guidance for design of support, selection of excavation method, reinforcing method of rock wall and monitoring plans.

Laboratory tests on compaction behavior for middle expansive soil and flyash-treated soil have been carried out. And the dry density and degree of compaction changing specificity experiment after immersion , the varying character of unconfined compressive strength and modulus of compressibility in different soak periods and different wetting and drying cycles have been carried out in the state of optimal water content and different degrees of compaction. so as to study the water stability specificity of middle expansive soil and flyash-treated expansion soil. Test results show that: the range of compaction water content for flyash-treated soil is larger than middle expansive soil; this has brought great convenience for flyash-treated soil roadbed’s execution. And after absorbent, the fly ash-treated soil’s dry density and degree of compaction changes is smaller than middle expansive soil; less full water capacity, the variation of strength is small also. After different soak periods and different wetting and drying cycles, the strength of modified soil generate dramatic decay in the initial, and drive to stability of status in the last. But the property of strength decay have great improvement than the without modified soil; the water stability of flyash-treated soil is good.

The adjustment of nonlinear stress is not taken into account in the limit equilibrium analysis of rigid body; and it is difficult to judge the convergence of the shear strength reduction method with FEM. To solve these problems, based on multi-grid method, structure grid for nonlinear FEM and sliding surface grid for calculating safety factor were established separately. So the sliding safety factor of arbitrary sliding surface or sliding blocks can be obtained. Thus limit equilibrium analysis can be integrated with nonlinear FEM. To increase calculating scale and speed, a 3-D parallel finite element code based on element-by-element method, TFINE.Pfem, is developed and used. The influence on result precision by grid were analyzed. Then it is applied to the stability analysis of Jinping high slope. The contrast analysis show that the safety factor obtained from the method proposed is larger than that of limit equilibrium analysis of rigid body because of considering of adjustment of nonlinear stress. The method porposed is accord with real conditions.

The conception of the groundwater level is described; and the characters of the groundwater under the normal atmosphere pressure and vacuum pressure are analyzed; thus coming to the conclusion that the groundwater level is the top surface of the gravity water or the interface between the gravity and capillary water; and the zero pressure line is the ground water level when under the normal atmospheric pressure but not when under the vacuum pressure. Based on the force equilibrium equation and gas state equation, the existing problem for the conventional technique is analyzed. It is concluded that the conventional technique can’t measure the true groundwater level. The water height measured is really the zero pressure line and the water-level fluctuation essentially reflect the average dissipation of pore water pressure in filter zone when the mouth of pipe is always open; the big error will occur due to the difference of the vacuity between in the sighting pipe and under the sealed film when the mouth of pipe is always sealed and it will become bigger and bigger as the reading times increase. So a new measuring technique that the true groundwater level can be calculated according to the force equilibrium equation by using the readings of the pore pressure gauge and vacuum meter in the sighting pipe is presented. The new measurement device can continually measure the variation of the groundwater level but not influence the results.

In light of the Guomao Metro Station of Beijing Metro line 10, and using ABAQUS software, the construction process and construction effect on the adjacent pile foundation19-1 of Guomao Bridge are simulated; and the deformation and force character of pile foundation as well as the interaction mechanism of pile-soil are studied. The partial results acquired by simulation and measurement are compared; and a mass of harvest is achieved. The conclusions are reached that pile foundation19-1 of Guomao Bridge is safe during construction; and existing construction; project is reliable. The basis and guidance are provided for succedent Guomao Metro Station and similar engineering construction.

The slope stability analysis is studied with the nonlinear failure criterion based on the plastic upper limit theorem. The tangent method is assumed to analyse the upper limit solution along the different brusted surface of slope in order to infere the stability coefficient formulas with the nonlinear failure criterion. The initial-tangent method is proposed for the complex slope with logarithmic spiral crack surface; and it can calculate the plastic analysis upper limit solution well. A classical slope calculation case shows that the presented method is of correctness and high precision which agrees well with previous achievements. The new method can be used to guide the slope stability analysis with the nonlinear failure criterion based on the plastic upper limit theorem.

The influence factors of the stability of karst cave under highway roadbed contain fuzzy information and the influence grade is not same. Based on the exploration data of a practical engineering, combined with the analytic hierarchy process (AHP) and fuzzy multiple attribute decision making (FMADM), a model of fuzzy multiple hierarchy multiple attribute making for stability evaluation of karst cave under roadbed is set up. Then the advise of the weight matrix elements of analytic hierarchy process fuzzy conversion which proposed by Laagoven & Buckley is adopted and the formulas of vectors calculation is educed when the weight matrix elements is triangle fuzzy number. The fuzzy utilities of every comment are gained by using fuzzy swing average weight (FSAW). Finally, appraisement of karst cave fuzzy sets is gained by ordering the fuzzy sets. The results of engineering application demonstrate the feasibility and validity of the method, which provide a new idea and method for stability evaluation of the roadbed in karst region.

The shear strength of unsaturated soil will be increased due to matric suction, which is effective stress. According to Fredlund’s shear strength theory of unsaturated soil, the matric suction on the inter-slice and the base surface of slice is considered in the limit equilibrium analysis of slope at the same time. An objective function based on limit equilibrium analysis is created and is applied to seeking most hazard failure plane with the sequence of linear programming (SLP) optimization method. An example of engineering is given, it is shown that the analytical idea in this paper exerts an influence on the stability evaluation of slope.

Based on the previous studies of others, the incremental calculation method is applied to the composite retaining system of cement-soil piles and soil nailing(CRSCSPSN). According to the unloading effect of excavation and the forming mechanism of soil-nail forces, the establishment method for the proportional coefficients of soil-nail forces is presented and the method makes it possible to calculate the soil-nail forces by increments. The incremental calculation method can effectively explain the influence of construction on soil-nail forces; and the calculation results of this method are more consistent with those of the measured. According to the deformation compatibility between the cement-soil piles and soil nails, and the relations between force and deformation both for soil nails and cement-soil piles, the simplified deformation calculation method for CRSCSPSN is presented. The deformation calculation method proposed is also based on the incremental theory. At last, there is an engineering case of which the calculated horizontal-displacement results and measured results are compared; and the comparison conclusions show that the simplified calculation method of horizontal displacements for CRSCSPSN is acceptable and effective.

Based on the triaxial tests of middle-liquidity limit silty clay and fly ash soils (1:2) of roadbed fillings, the dynamical characteristics of middle-liquidity limit silty clay and fly ash soils(1:2) are analyzed. Compared the characteristics of the two materials, the variation law between the dynamic shear strength and the number of circular load is educed. Then the relationship formula of the dynamical elastic modulus and elastic strain is set up. It is found that the fly ash soils (1:2) is better than middle-liquidity limit silty clay in dynamic shear strength. It has superiority as roadbed fillings.

It is evident that unsaturated soils are usually encountered in nature and engineering practice. Hence, the understanding of unsaturated shear strength behavior is necessary. The shear strength behavior of unsaturated soils is investigated on the basis of pressure plate test and direct shear test. The results show that the angle of internal friction decreases with increasing degree of saturation and the cohesion attains its peak value at degree of saturation 40 % ? 60 %. According to these results, the unsaturated shear strength behaviors of non-cohesive and cohesive soils are demonstrated. The internal friction angle of non-cohesive soils increases with increasing matric suction; and the pseudo-cohesion attains its peak value in primary transition zone and then decreases. The cohesion of unsaturated cohesive soils increases with increasing matric suction until threshold suction reaches. The threshold suction is the minimum suction at the residual zone of unsaturation. The cohesion of unsaturated cohesive soils can be predicted before the threshold suction, because value is approximately constant. Moreover, the state paths influence cohesion in excess of the threshold suction.

Based on the nonlinear model for unsaturated soils , a thermo-nonlinear model for unsaturated expansive soils is presented through modifying the parameters and taking account of thermal effects on deformation of soils. The model consists of two aspects, i.e. the deformation of soil skeleton and the water volume change of unsaturated soils. Total of 18 parameters are involved in this model. All the parameters can be determined using laboratory tests. A series of controlled temperature triaxial tests have been conducted; test results of reconstituted unsaturated bentonite clay are presented. The controlled temperatures are 15℃, 30℃, 45℃ and 60℃ and the thermal effects on shear strength and Young’s tangent modulus are discussed. The research results show that the specimens with higher temperatures show higher shear strengths and Young’s tangent modulus. The formulas of shear strength and Young’s tangent modulus taking account of temperature are proposed.

The triaxial creep experiment of artificial frozen soil in deep alluvium is performed by using self-developed a W3Z-200 apparatus of triaxial creep frozen soil. Analyzing the experiment results, applying parabolic yield criterion for improved viscoplasticity in the Nishihara model and coupling degree of temperature, a new creep constitutive model is established for describing frozen-soil's creep characteristics under the complicated stress state. The model is embedded in nonlinear ADINA finite element program in order to numerically analyze easily. Numerical simulation of the shaft well excavation process and field measurements of deformation of deep soil frozen wall are performed in Huainan Mine; and the results show that the established parabolic yield-surface constitutive model is correct and reasonable for FEM numerical simulation of deep soil frozen wall.

Based on the idea of virtual reality，A triaxial test computer simulation courseware is developed. The triaxial test courseware used Authorware software and a closed-form formula of excess pore water pressure of soils during consolidating are introduced. Based on the modified Cam clay model, the deductions of excess pore water pressure, the curve of stress-strain, the path of effective stress path（ESP）and total stress path（TSP）during undrained triaxial test are discussed. Finally, this deductions are programmed in the triaxial test courseware. Using the courseware, the students can not only do operation Training before lab test, but also grasp of the basic soil mechanic principles profoundly.

The methods of 3D stratum modeling by multi-DEMs and triangular prisms can cause many redundant triangular-facets and slim triangular-prism meshes, so they aren’t propitious to fast scan the 3D stratum model, or used for the numerical simulation meshes. The TIN model can adjust the area and amount of the triangular-facets, so it can avoid redundant data, when it is used to represented the stratum interface. The TIN model can be built by the incremental insertion algorithm with the discrete points, and converted from grid (generated by Kriging interpolation) by greedy insertion; and it also can be built by the topographic contours. The cutting method between TIN models is presented to implement Boolean operations for stratum interfaces and faults 3D modeling. The multi representation methods are developed with the Visualization ToolKit; and the stratum body can be vividly represented by controlling the layer’s color, texture and material. At last the 3D stratum model of Longtan Hydropower Station is built to validate the theories and programs.

Visualization and analytical techniques for the solid models of geological entities are the intuitionistic, convenient approaches to express complicated geological structures and property parameters inside the geological body. In 3D geological modeling, it is one of the most important research fields that focus on visualization representation and analysis of the complicated geological data, interactive revelation and analysis for 3D geological models. This paper introduces the general operations for 3D-interaction of the solid models of geological entities. It expounds the interactive and analytical technique for the 3D geological model. It realizes several visual operations on 3D geological model including geometric transformation, spotting and the measurement of property value in any spatial position, slice up, virtual drilling, virtual roam, the excavation of foundation pit and tunnel. Those operations, which are based on software-oriented techniques, use 2D devices such as keyboard and mouse to the simulation of 3D spatial data, and will increase the comprehension of 3D geological model.

A simplified analytical method is presented for nonlinear analysis of the behavior of composite foundation with rigid piles. An elastoplastic relationship between the shaft shear stress and the relative shaft displacementsis adopted. The development of settlement, skin friction, stress and neutral plane on piles is investigated through the proposed approach. Comparisons of the load-settlement responses the finite element and difference calculation methods are given to demonstrate the effectiveness and accuracy of the proposed analytical method.

Taking the cross-sectional area of a gravity retaining wall as the objective function, and regarding the stability of gravity retaining wall and the bearing capacity of groundwork as restraint conditions, and then the problem of best cross-section selection of gravity retaining wall can be transformed to a question to solve a nonlinear optimal design under some specifical restrictions; and then to solve it by the PHR method. Base on the theory interpreted above, a corresponding program is compiled to solve the question; and the relationship between soil parameters and the optimum cross-sectional area is analyzed. At last, an example is given; it is shown that the optimum design is better than the original one.

The three states of saline soil are different from the common soil, the salt liquor and salt in soil granule have a homeostasis with the changing of the outside environment (such as temperature, humidity and artificialness), there may be easy to have engineering disasters when the saline soil is used in roadbed, such as the frost boil, the expansion of saline soil, the dissolve falling, the roadbed soil pickled and so on. Aiming at analyzing the saline soil characteristics and the improving mechanism, the treated method is brought forward. The results of study indicate that adding the improving stabilizer into saline soil can improve the CBR property greatly and can meliorate the stability of sucking water clearly, make the soil melioration, finally, gain the solution of the problem of the disasters in roadbed.

On the basis of rock failure process analysis（RFPA）code, together with the time-dependence of the rock progressive damage and the creep constitutive relation of the characteristic elements at a mesoscopic scale, the rheological model of rock in the failure process under loading is further developed. Using the further developed RFPA code, the progressive creep failure of rock specimens under constant loading was numerically simulated and the typical time-dependent deformations: the transient creep, the steady-state creep and the accelerating creep were also represented. The fact that the simulations are well tallied with the observations in laboratory shows that the rheological model is appropriate to investigate the nonlinear complicated creep failure of rocks. The numerical simulations indicate that the macroscopic creep failure is induced by clusters of microfracturing at a meso scale. The above numerical results offer us some important theoretical indications and practical instructions to further investigate the instability failure mechanisms of engineering rockmass and take some precautions to prevent their occurrences of rock hazards in rock engineering.

Soft soil is a material with the characteristics of viscosity, elasticity and plasticity. Till now, we have not yet seen researches on the creep laws of soft soil by using the models of fractional calculus. A number of one-dimensional consolidation tests for the Pearl River Delta typical soft soil have been carried out; and the creep laws of the soft soil are simulated by using fractional Kelvin model. The creep compliance and relaxation modulus of fractional Kelvin model and its application are discussed. It is shown by comparison with the traditional Kelvin model that fractional Kelvin model can simulate the creep compliance curves accurately. It has a simple and uniform form, only a few of the parameters should be adjusted in the calculation processes. It is predictable that fractional Kelvin body will have wide applications to the field of rheological constitution of soft soil and its calculation.

soft soil is stabilized by slag cementitious materials, which can not only reuse industrial wastes, but also reduce amount of cement. Sandy soil and clay soil are stabilized by slag cementitious materials. Result shows that the stabilization effect of alkali-slag cementitious materials is better than cement and lime. The unconfined compressive strength of soils added 9 % slag cementitious materials after curing 28 days reaches 2.0 MPa, which are higher than soils added 15 % cement; softening coefficient of stabilized soils after curing 28 days are almost higher than 90 %; the CBR of stabilized clay soil outclasses that of the lime-clay soil with the same mixing ratio. XRD analysis shows that the high-strength, insoluble mineral produced due to hydration of slag cementitous materials is the main cause for better effect of soil. All those show that alkali-slag cementitious material is an ideal solidifying agent for soil stabilization.

Breakout blasting often responds 40 %－60 % fracturing soil quantitative during the course of the whole frozen soil blasting tunneling in shaft. Wide pitch-row breakout blasting can increase the effective application of free face and consolidated reflection and tensile affection of free face stress wave and cancel or reduce the decreasing field in frozen soil. Theoretical analysis and model test of binocular explosive funnel have been presented to the most important parameter, dense coefficient of borehole in breakout blasting, and the volume of explosive funnel, v, and the maximal convex capacity, h, between two boreholes after blasting also has been thought synthetically. The authors think dense coefficient of borehole, m=1.5 is reasonable. Combined with the arc layout of breakout bore of vertical well and the feature of frozen soil with relative bigger restriction effect, the dense coefficient of borehole of breakout blasting in shaft suggested should be decreased rationally based on it, which was proved in further engineering practice.

Laser real-time holographic interferometry is applied to research the whole failure process of three-point bending beams of steel fiber concrete(SFC). The real-time holograms of crack growth on SFC beams are continuously captured. According to the active fringe’s movement and distribution on the SFC specimens as well as the hologram’s interpretation, the initiation and development of crack in SFC and its deforming character can be exactly visually shown. The experiment indicates the effect of steel fiber preventing fracture and increasing toughness is obvious while the content of steel fiber in concrete specimens is higher than 1.0 %. Based on the calculation of fracture parameters and its analysis, It is clearly revealed that fracture energy is a sensitive parameters for reflecting the effect of steel fiber preventing fracture.The fracture behaviour of the SFC specimens demonstrated by active fringes distribution is in accordance with the result from the explanation of fracture energy in SFC. Laser real-time holographic interferometry can provide an effective experimental support for concrete fracture mechanics.

Compressive tests on cubic specimens were conducted at different strain rates using a servo-hydraulic multiaxial testing machine. Considerable emphasis was laid on the dynamic strength and deformation properties of concrete in biaxial stress state. The lateral pressure was kept in proportion to the main axial load with the ratio of 0:1, 0.25:1, 0.5:1, 0.75:1 and 1:1 respectively at the strain rate ranging from 10-5/s to 10-2/s. From the test results it is revealed that the dynamic strength is enhanced with the increasing of strain rate. The shear failure envelope is enlarged by 2 %–10 % in case of the strain rate increasing by one order of the magnitude compared with that under static loading. The modulus of elasticity also increases with the increasing of strain rate. The linear part of the stress-strain curves tends to extend as far as strain rate increases, while the curvature of the nonlinear part tends to diminish. Moreover, strain rate has little influence on the fracture modes of specimens in biaxial stress states.