According to effective stress dynamic analysis method and based on Byrne’s effective stress elastoplastic model, a new modified model is presented. This new model can consider these aspects such as rotation of principal stress axes, a little of gas, strain softening and stress redistributing after liquefaction. The analytical modules are programmed and interfaced with the FLAC code; then numerical simulating analysis of saturated sandy soil under single-point, two-point and multi-point explosion seismic waves respectively are carried out by using FLAC code which is a two-dimensional explicit program. The 3 kinds of fields such as the level, little-obliquity and slope grounds are considered; and the difference of the characteristic of saturated sandy soil between under explosion seismic waves loadings and natural seismic waves loadings are contrastively investigated. The results of numerical simulating indicate that the explosion liquefaction characteristics of saturated sandy soil can be well described with this model; the dynamic characteristics and liquefaction behavior of saturated sandy soil are different under different fields and different dynamic loadings.

Based on the one dimension dynamic stress-strain relation Davidenkov skeleton curve, which is corrected by using sectional functions; and the upper limit of failure shear strain amplitude is used as the sectional point. The dynamic shear stress-strain circle curves are constituted by referencing Mashing rules and implemented by sub-program based on ABAQUS finite-element software. A representative soft site in Nanjing City is selected; and its dynamic nonlinear response are calculated when a cosine time-history curve and seismic acceleration waves with different peak values are inputted from bedrock interface. The results prove that the developed dynamic elastoplastic constitutive relations of soil are feasible and accurate; and it can be used to investigate the nonlinear earthquake response analysis of general site.

The effects of the consolidation ratios on the maximum dynamic shear modulus and the dynamic shear modulus versus the shear strain of sands are presented by using the resonant column method. The effects of the dynamic shear modulus versus the shear strain under different consolidation ratios on spectrum of surface ground motion are evaluated by the soil layer response calculation. The Fujian’s standard sand and Harbin’s sand of China are employed in the tests. The recommended formula considering the effects of the consolidation ratios on the maximum dynamic shear modulus of sands is given. The new formula indicates that the increasing degree of the maximum dynamic shear modulus due to kc>1 is significantly larger than that described by Hardin and Black’s formula. The effects of the consolidation ratios on dynamic shear modulus versus the shear strain and surface ground motion are demonstrated. The results indicate that the dynamic shear modulus versus the shear strain increases with increasing of the consolidation ratios; and the effects of the consolidation ratios on dynamic shear modulus versus the shear strain should be considered for the incidence of the strong shock.

To make measure and research on the infrared hot image in the deformation and destruction course under pick cutting is carried out in order to analyze the deformation and destruction law. To change the pick type, cutting speed, cutting depth, tooth style and measuring position is carried out, so as to measure its infrared picture. It is found that there appears a bar of high-temperature district in the direction vertical to cutting direction while knife teeth are cutting the coal. While there is a point of high-temperature district when point-attack pick cuts the coal. The faster the cutting speed is, the more obvious the heat effect will be. In the course of pick cutting, the highest temperature value in temperature field is relative to cutting depth and mechanical characters. The deeper the cutting depth is, the highest temperature is in the temperature field. The bigger the tensile strength, compression strength, adhesion stress and inner friction angle are, the highest temperature is in high temperature district.

The first problem of tunneling in permafrost area is how to excavate and how to lining at the same time, because the needed temperature for construction of liner is different from that of excavation. Excavating needs lower temperature for stability of wall rock, while construction of lining needs higher temperature for concrete strengthening. By finite element analysis of temperatures inside tunnel, four phases (safe phase, relatively safe phase, safety precaution phase and potential safety troubles phase) suitable for construction are put forward to guide excavation and construction of lining.

Concerning the rare study on physico-mechanical properties of phosphogypsum, the relationship of water content with baking temperature and baking time, as well as the relationship of solubility with temperature is investigated by lots of experiments. According to specification of soil test, the tested water content of phosphogypsum increases with the increasingly baked temperature and baked time. In fact, the water content should be a constant, so the experimental method has to be improved. Phosphogypsum is suggested to test the water content under 55－60℃ for more than 36 hours. Through the experimental results, phosphogypsum has certain solubility, which decreases with the growing solution temperature. Because of the solution property, the distilled water must be substituted by the saturated phosphogypsum solution when the seepage experiments and triaxial compression tests are done. It is found that the coefficient of permeability in vertical direction is more than that in horizon direction from the seepage test results. And this property is different from the normal tailings. it is also found that phosphogypsum has obvious dilatancy when being sheared through the consolidated-drained triaxial compression tests. A conclusion can be drawn that the pore water pressure is minus when phosphogypsum specimen is damaged, and that the strain of damage is not sensitive with the confining pressure. Making use of the dilatancy of phosphogypsum, the safety of phosphogypsum dam can be forecasted theoretically by the pore water pressure monitoring system.

Terzaghi’s one-dimensional consolidation theory is modified based on the non-Darcy seepage equation considering the initial hydraulic gradient, and the finite difference scheme is introduced. The effects of the initial hydraulic gradient on the seepage front, the pore water pressure and the degree of consolidation are thereby investigated. The analytical results indicate that, for the soil with the initial hydraulic gradient greater than zero, the hysteretic appearance of seepage flow in the soil layer apart from the drainage boundary makes the rate of consolidation less than that by applying Terzaghi’s consolidation theory. In addition, it is validated that the ultimate value of average degree of consolidation is less than 1 since there exists some residual pore pressure which cannot be completely dissipated in the soil layer.

The distributing rule of additional forces of compressible shaft wall is given by numerical analysis and model test. It is shown that the compressible shaft wall can reduce the additional force and the section axial stress of shaft wall effectively; Compared to the single compressible tie-in, two compressible tie-ins setting is more effective. The setting optimization principle of compressible tie-in is brought forward; and it has important guidance meaning to design compressible shaft wall reasonably.

Based on simulation theory, a geomechanical model is established. The paper introduces the design and process of the experimentation. By way of experimentation of 4 slope models, we study the stability of archetype slope, the correlation between the stability of consequent rock slope and obliquity of rock layer. After analyzing the phenomena and data of the experimentation, it is found that the major deformation model is slippage. The mode of breakage is sliding and fracturing. The process of slippage is graded. The more hinder the position of coast is, the small the obliquity of rip face is. The deformation and breakage of bedding slope firstly arises at the dig face near the earth's surface. The bigger intensity of rock layer is, the steadier the bedding slope is. The small the obliquity of rock is, the steadier the slope is.

Based on experiment using the typical artificial MSW to study the transient modulus changing of MSW is carried out. The study has shown that the transient modulus of MSW is changed when the organic content, the initial moisture, the initial void ratio or the degradation degree of MSW changing; and some changing laws due to influences of above-mentioned factors are obtained. The mechanism is analyzed combined with the property of MSW. These conclusions are very useful to the research of distortion of landfill and the design of landfill in the future.

The problem of hydraulic fracturing in core of earth-rockfill dam is an important and unsolved geotechnical problem. In this paper, the mechanism to induce and propagate hydraulic fracturing is investigated based on analyzing loading and deformation in the core. It is indicated that the incipient impounding period is the most dangerous one during which the hydraulic fracturing may occur easily in the core; and that the hydraulic fracturing does not take place in a core with perfect homogeneous soil. The cracks or local serious weaknesses in the core and the incipient impounding period are two important conditions to induce the hydraulic fracturing; and the essential cause to induce the hydraulic fracturing is the existence of local high hydraulic gradient. Finally, a simple test is performed to validate the above mechanism. The suggestion to further study on the criteria, numerical simulation to the hydraulic fracturing are presented.

By measuring the velocity of the P wave and S wave on the three orthotropic different directions including parallel and vertical direction to the stratum of the compacted rock samples including slate, phyllite, mylonite and metasandstone, the two obvious anisotropy effects of P wave and S wave velocity are put forward. One is the conformity of the anisotropy of P wave and S wave velocity expressed by that the anisotropic indexes of S wave velocity would linearly increase as the P wave anisotropic indexes increase in a great degree, namely the anisotropy of S wave velocity is statistically proportional to that of P wave; the other effect is the variation between P wave and S wave velocity anisotropy, which is mainly expressed by that the anisotropic index of the P wave velocity is usually greater than S wave in the parallel and vertical directions to the stratum of the rock samples which means that the anisotropy of S wave velocity is inferior to that of P wave. Using numerical value test based on the wave velocity function of the transverse isotropic elastic medium, the two effects are validated.

A usual discriminant analysis method-Fisher’s discriminant analysis is introduced. Based on Hefei-Liu’an-Yeji Expressway Project, sampling soil’s discriminant analysis of swelling potential ultilizing the software of SPSS is conducted, discriminant equation suiting for the district is obtained; and several conclusions are drawn as follows:(1) Only several basic physical indices are acquired in the analysis, the operation of which is popularization and standardization. Lots of advantages such as easy test condition, simple facility and short periodic time can be obtained and a correct classification can be done on the basis of statistics. (2) The value of coefficient of plastic index is maximum, which means that discriminant equation is sensitive to plastic index and that plastic index can reflect swelling potential to a well extent. (3) It is easy and efficient to do discriminant analysis making use of SPSS, statistic significance of classifying is explicit and it can provide grounds for the discriminant of expansive soil. Tests for the equation are carried out and from which we can see that it has good prospect for the identification and classification of expansive soil.

According to deformation observation data analysis of typical landsides, such as Jiming Temple landslide etc., the deformation failure mechanism is summarized; and then the mechanism is applied to slope stability analysis as the failure criterion by adopting strength reduction method and gravity increase method. By classical instances, the failure criterion based on deformation trend is suggested; various factors effecting computation accuracy are also analyzed; and at the same time, the reliability and stability of previous methods are demonstrated. The result indicates that the failure criterion has a clear concept, special physical meaning and distinct definition for slope stability analysis. By comparison, the precision and reliability on basis of strength reduction method is better, and can be applied to most slope stability analysis.

Seven methods of calculating the post-construction settlement for soft soil embankment are introduced; and the prediction accuracy of each method is analyzed based on actual measuring settlements. For each prediction method, the influences of calculation starting time and time span on the accuracy are studied; and each method’s advantages and applicability are analyzed. The research results show that hyperbola method and exponent curve method’s predicting errors are larger, after three months’ permanent load as the time starting point is proposed; a longer period of settlement data prediction can effectively improve predicting accuracy. Three-point method’s, settlement rate method’s and Hushino method’s predicting precisions are higher, and the calculation starting point and time span do not have much relation, but require special treatment to the original observation data , the calculation is more complex. The predicting results of Asaoka method is closest to truth value; its shortcoming is unable to predict the settlement which after a certain stage of stop load-on.

Although lime-treated soil has been widely used in the road construction with many application experiences, the determination of the optimum water content in the parameters control of construction still needs to be deeply discussed. In this paper, the method to determine the optimum water content of lime-treated expansive soil in the road engineering is analyzed; and a new method, different from the corresponding testing standards and technical specifications for the ministry of communications, is presented; and it is illustrated that the optimum water content in the lime-treated soil should be 3% larger than the one determined by the compaction test.

An effective technique of measuring the shear bands is put forward using digital photogrammetry and image correlation analysis. At first, a series of specimen images were collected by digital camera with high resolution. Subsequently, the approximate region of shear band was identified firstly in the full observed scope on the image by coarse image correlation analysis for saving time. And then refined analysis in the local observed scope, where the shear band occurred, was conducted by specifying pairs of alinement points on image with one pixel interval covering the shear band. Finally, when shear band was recognized, its edge points were marked manually for the subsequent quantity analysis of the thickness and direction of shear band together with the deformation inside. This technique is more accurate than the widely adopted method of painting mesh on soil specimen. Its application is illustrated by a large-scale direct shear test of granular soil.

Based on the theories of Mohr-Coulomb and Hoek-Brown and Duncan-Chang, the anchored effect of some kinds of rock masses are analysed; and the results of that the cohesive strength of rock masses and the shear strength of the rock joints have been improved by bolts or cables are established. . Through analyzing the tests results, the development of analytical constitutive equations based on the thesis of shear stress is in proportion to bolt or rock mass relative displacement are established; and the analysis of parameters are carried out; it is shown that the reinforcement effect may be improved and enhanced by increase the magnitude of applied load and the diameter of bolt or cable and anchored length. Under previous researchers’ studying works, the development of the analytic model which the interface decoupling between bolt and grout medium or rock masses has been established based on above-mentioned analytical constitutive equation.

A new definition of generalized equivalent confining pressure is proposed in term of that the function of reinforcing material in the reinforced soil is equivalent to confining pressure. Expression of the generalized equivalent confining pressure is set out by difference of confining pressures between reinforced and un-reinforced soil samples at the same strength. And limited balance equation of reinforced soil, in which 2 indexes (?, ?) are used to estimate the strengthening effects of the materials, is carried out according to the fact that the Mohr-Coulomb theory is also obeyed in reinforced soil. The tests of laterite reinforced by flexible materials show that, the index ? is close to 1 in different drainage conditions, and the index ? varies with drainage conditions in which it is greater than 1 when drained entirely and smaller than 1 when not drained; and it is related to rows and properties of the reinforcing materials when concreted but un-drained, the generalized equivalent confining pressure is minus when not drained or concreted but not drained and positive when drained entirely. The index ? and the generalized equivalent confining pressure increase when more materials used.

The ultimate capacity of piles is always determined using a failure criterion. Due to the differences in failure criteria, the ultimate capacity of piles and the reliability index obtained using different failure criteria may not be the same. It is necessary to analyze the reliability levels corresponding to various failure criteria, especially S-lgt criterion used in Chinese technical code for building pile foundations. For this purpose, a bias factor defined with respect to S-lgt criterion is introduced; and one database for static load tests of bored piles is utilized for detailed evaluation of the bias arising from failure criteria, the corresponding reliability are further analyzed. The results indicate that there is a considerable bias of different failure criteria. Moreover, the failure criteria have a significant influence on the reliability of pile foundations. The reliability index based on S-lgt criterion is on the high side among seven failure criteria used in this paper. The actual safety levels of designs with the same nominal reliability index are not the same.

Based on the isotropic elastoplastic damage and Prevost model theory, a new dynamic elastoplastic damage model for saturated soft clay under undrained cyclic loading is presented. The new model combines isotropic hardening, kinematic hardening and isotropic damage. Then the damage evolution equation is established according to the accumulative plastic deviatoric strain to describe the destruction of the soft clay under cyclic loading. Finally, the validity of this model is confirmed by simulating cyclic triaxial test. It is shown that the new model can preferably depict the deformation, pore pressure variation and modulus damage of the saturated soft clay subjected to the cyclic loading.

The judgment criterions of the rock mass stability have not arrived at round phase. A series of basic problems have not formed the code for design about the judge rule of the rockmass stability from the definition of stability to the quantitative standard. The range of the stability of surrounding rockmass can be defined by the plastic zone or the displacement changing zone at present. By using the elasticity theory and basic idea of the safety factor in the engineering, the paper develops a new safety factor method based on the element by the Mohr-Coulomb and Drucker-Prager rule. The safety factors are solved by FISH in the FLAC3D. The quantity standard and the safety range of the rockmass stability are developed by the safety factor for the provided reasonable supporting parameter in the reinforced engineering.

The generalized nonlinear strength criterion unifies all kinds of the nonlinear strength criteria about the friction material, so that the criterion can represent the strength characteristic of these materials. The shape parameter α is one of the factor that affect the shape of the failure curve in the generalized nonlinear strength criterion, the research about the parameter α is done as follows: (1) The generalized nonlinear strength criterion is applied to the sand, and then, according to the character of the failure curve in the generalized nonlinear strength criterion in the ?-plane, for judging the failure curve convex, the relation between the least of the parameter α and the failure stress ratio Mf was deduced. (2) By some test results about the sand, the proposed criterion for general stress state was applied to simulate test results; and it was shown that the criterion could reproduce the test data fittingly. And then the linear relation between the two parameters in the criterion was found. So the failure behavior of the sand could be reproduced by the use of triaxial compression condition for practical application.

With the review of disadvantages of traditional deep mixing cement-soil column techniques in China, which have resulted in many engineering problems and doubts about the effectiveness of the deep mixing techniques, a new bidirectional deep mixing column technique developed by authors is introduced. Comparison tests between the new and traditional deep mixing column techniques have been conducted in a highway construction site for soft ground improvement. The test results show that the quality of the cement-soil column constructed with the new technique is much better than that with the traditional one. The results of standard penetration test (SPT) and unconfined compressive test indicate that bidirectional deep mixing columns are more homogeneous in both horizontal and vertical direction. The electrical resistivity measurement results of core samples also present that more homogeneous microstructure is formed in the bidirectional deep mixing column. It is concluded that the new deep mixing technique should be popularized for soft ground improvement.

Mallat binary wavelets quick algorithm of multiresolution analysis is used here. And Db5 wavelet is introduced to analyze instantaneous response curves of fracture, break and shallow defects piles. It is shown that from the results of wavelets transform, reflected waves of defects and pile bottom can be found clearly; and locations of these defects can be acquired easily so as to offer guidance of repair plan.

Along with the exploitation of the underground space approaches to the deep constantly, some phenomenon cannot be fully explained by mechanics of continuous media. The Protojiakonov’s Theory as a breakthrough, the shortage of the pressure calculation is found out from quantitative angle by analyzing example. The result from strength theory is in tally with the actual physico-mechanical truth. The shortage of strength theory is shown that in the continuity theory-frame also; mainly because the invisible district wasn’t considered. The new methods must be adopted in order to describe the rock-pressure accurately.

Rock-mass parameters are very important to underground cavern design and construction; many application studies about calculating rock-mass parameters have been implemented by back analysis of displacements. In order to improve parameters back analysis, the uniformity design theory is introduced to design training swatch for neural networks, rock-mass mechanical parameters of underground cavern are obtained from measured displacement messages. The back analysis finite element software is implemented based on three key techniques: object-oriented, adaptability and visualization, which can be used as visualized back analysis and forecast tool. Rock-mass parameters back analysis is implemented by mean of “graph－finite element analysis－graph” instead of “data－finite element analysis－data”, it can instruct design and construction in time with monitoring technique and stabilization analysis. It is illustrated that this software is very useful by the example of the underground cavern of a hydropower project.

A decoupled method for elastoplastic consolidation is investigated. Firstly, an elastoplastic constitutive model is constructed based on numerical modeling method. Moreover, the uniform matrix expression of the model for axisymmetric and plane strain problems is deduced. The model is applied to Biot consolidation theory. Then the incremental governing partial differential equations are established by using this method. According to stress paths, the decoupled conditions of these equations are discussed. Based on that, a diffusion equation and uncoupling governing equations are presented. Moreover, the method is applied to numerical analyses of two examples. It was indicated that this method is reasonable, and can reflect the effect of dilatation.

Based on stress dropping model, an elastoplastic-brittle model is established by using a softening threshold value to model the character of the geotechnical materials, twin shear strength theory and non-associated flow principle are used, and the large strain of softening zone is considered, a solution to cylindrical cavities expansion in elastoplastic-brittle materials is obtained. An example shows that the softening threshold value remarkably influences the deformations and range of the plastic zone; smaller threshold value leads greater expansion deformation, plastic zone range, and ratio of softening zone to entire plastic zone; and that considering the effects of intermediate principle stress on plastic yield or not, obviously influences the results.

By sample resistivity testing , resistivity logging and resistivity section measuring for the silty soil layers which has been formed from 1964 to 1976 year in Yellow River estuarine area via Daokou area of Dongying City in China’s Shandong Province, the relationships between water content, porosity, water saturation, resistivity of pore water, mineral characteristics and electrical resistivity for silty soil are discussed. Research results show porosity is the main factor to control the resistivity for silty soil in Yellow River estuarine area. The resistivity for silty soil would decrease as the porosity and water content increasing; the relation formula between the resistivity and porosity also is given. Based on these results, the micro-structure of silty soils and space distributing of silty soil layers also have been mapped with resistivity logging and resistivity section measuring data successfully.

The probabilistic model of rock and soil mechanics parameters affects the results and precision of reliability analysis and design. Based on testing data and some groups of prior distribution data (existing in history) in the same zone, this paper discusses the problem of how to estimate the distribution of rock and soil mechanical parameters for a small sample in the case of insufficient data. A multiple sources information fusion method based on Bayesian statistics theory is presented. Confirming the weight of every prior distribution by calculating the difference between its prior data and testing data, this paper brings about the optimum fitting of probabilistic model of rock and soil mechanical parameters.

Based on a new kind of rockfill power function creep constitutive model which can simulate high confining pressure state of rockfill, the developing rule of rockfill creep and the engineering method of control creep are studied. The results show that the computation value of dam deformation will be less than the real one without consideration of rockfill creep because of arch action. The creep of the rockfill during early stage is suppressed. But the arch action will be weakened with heightening of dam, increasing of water pressure and developing of rockfill creep. The temporary section of CFRD is made use of blocking water or overflowing as possible in order to decrease rockfill creep during late stage. The construction date of the face slab delays several months than the rockfill below the face slab, which can rockfill creep.

The research on subsurface ground movement has a great importance in terms of the evaluation of the risks to the subsurface structures and pipelines influenced by tunneling. However, this is a topic about which is little known. According to the research by Mair et al (1993) who analyzed the subsurface data from various tunneling projects and centrifuge tests in clays, subsurface settlement profiles could also be reasonably approximated by the form of a Gaussian distribution in the same way as surface settlement profiles. Their equation based on this observation is widely used. However, a fixed value for surface settlement trough-width parameters K is used for clay in the equation, which causes considerable errors for different geological conditions. Also, because of the data they used， Mair equation is only applicable to clays. Based on field data analysis, a normalized ratio ?d is suggested in this paper to account for the different geological conditions; and a modified Mair equation is established which is not only suitable for the cases surface settlement trough with different width parameters, but also can be used for sands. Thus this modified general expression can be used to predict the subsurface ground movement with a broader adaptability compared with the original Mair equation.

In light of the characters of engineering geology and hydrogeology in Gansu Province and near areas, influencing factors of the design for waterproof and drainage in road tunnel are analyzed; the topographical features, vegetation, construction method, leakage of groundwater of loess and weak surrounding rock of highway tunnel in the district are investigated. Cause of leakage in the tunnel is analyzed. On the basis of the natural conditions, field investigation of seepage and disaster conditions of road tunnel, classification of outflow types for highway tunnel is presented with analogical method. Based on nine tunnels in Tianshui to Chankou Highway, principle of design for waterproof and drainage in highway tunnels construction is provided. Based on above analysis, four reasonable structural styles and section configurations for design of waterproof and drainage are proposed.

Based on the previous study, general empirical formula to calculate settlement at any point is advanced by combining three existing empirical formulae. Assuming soil is not drained, the computing formulas of soil vertical deformation induced both by bulkhead additive thrust, force of friction between shield and soil, and force of friction between follow-up pipes and soil are derived from the Mindlin solution in elastic mechanics. Combining the formula of ground deformation induced by ground loss, the formula of total soil vertical deformation induced by pipe jacking construction is obtained. This method can be applied to the construction phase. As is shown in analytical calculation, bulkhead additive thrust will make the frontal soil of excavation face heave and the rear soil subside. Surface deformation induced by bulkhead additive thrust is small during normal construction; and the curves are anti-symmetry with axes of excavation face. For the surface deformation induced by force of friction between shield and soil and induced by force of friction between follow-up pipes and soil, both of their curve distributions are similar to that of bulkhead additive thrust with the axes at the middle of shield and at the middle of follow-up pipes respectively.

With the sustainable development of economy in China, environmental pollution and some soils in city are polluted severely. Hence, protecting environment is of great significance for researching the polluted soil’s pollution mechanism, survey evaluation and treatment. The current situations of physico-mechanical character, pollution mechanism, testing techniques and risk assessments for polluted soil are summarized. Furthermore, research content and orientation are also pointed out.

A numerical analysis has been conducted to study hole size effects and failure mechanism of brittle materials containing multiple holes under uniaxial compression loading, by using the Realistic failure process analysis code (RFPA2D). Numerical model specimens with same sizes(height width = 65 mm 100 mm) , same periodic holes patterns, same void fraction (20 %) and different diameters holes have been numerically analyzed. The numerical calculation results show that the similar compressive strengths for the specimens are obtained. Moreover, a specimen tensile failure mode with no cracks localization has been observed, which allows us to conclude that there is no size effect engendered by the quasibrittle behavior of the considered brittle materials containing multiple holes.

By test of swelling pressure and expansion rate with cutting ring sample under different restrained pressures, it is shown that the restrained pressure has obvious influence on expansive soil’s expansibility; the greater restrained pressure is, the smaller expansibility is. On this basis, experiments in three kinds of different restrained conditions of expansive soil are designed:(1) the lateral, upside and downside of the expansive soil are restrained.(2) the lateral and downside of the soil are restrained, while the upside is unrestrained.(3) the lateral of the soil is restrained, upside and downside unrestrained. The test results indicate that different restrained conditions have obvious influence on expansive soil’s physical and mechanical characteristics such as moisture content, density, void ratio and shear strength. Furthermore, expansive soil is more easily deformed along unrestrained surface. Furthermore, when the upside and downside of expansive soil are unrestrained, the expansive soil’s moisture content is close to its liquid limit after sopping water. The study will provide important basis for the control of the expansive soil.