Large rock slides are a sudden geological hazards with the sudden high power release，which often cause heavy casualties and economic losses. The rock slide of locking section is a main type of large rock slide，and the development process is relatively concealed and the occurrence is quite sudden. In this paper，the locking section of a rock slide was subdivided into five types based on the existing form and the position of the locking section，namely，“three sections type”，“retaining wall type”，anti-slide block type，linear multilevel type and stepped multistage type. The engineering geological characteristics，the development of landslide and the characteristics of sudden instability were compared and analyzed with the specific locking section of landslides. In addition，the precursor information of instability，such as the initiation and coalescence of tensile cracks on the trailing edge of the landslide，the expansion on the leading edge，the deformation of the slope body and the acoustic signal characteristics of micro fractures in rock，were systematically analyzed in terms of the transient characteristics. According to the precursor information of different landslide instability in different stages of development，with the application of InSAR，LiDAR，GPS，3D Laser Scanning and rock microseismic technology，the early warning and control method of landslide instability was proposed by using the integration of the“space-sky-ground- interior”. The acquisition of the precursor information of landslides in different stages plays the important guiding role for the prevention and control of the sudden rock slide of locking section.

This paper concentrates on the acoustic emission(AE) characteristics of deformation field development of red sandstone under uniaxial compression. The digital speckle correlation method was adopted to measure the deformation field. The AE information was monitored by an AE system during the deformation and failure of the rock. The AE characteristics corresponding to the deformation localization and the stretch and dislocation of localization band were studied. The AE ringing counts and the AE energy increase suddenly when the stress drops abruptly. Sometimes，the stress does not drop abruptly when the AE ringing counts and AE energy increase sharply. There is a close correlation between the AE cumulative ringing counts and loading stress curve during the whole loading process，but the stress drop is not proportional to the increment of AE cumulative ringing counts. The development of rock deformation field may not be in a calm stage during the“quiet period”of AE. The size and value of deformation localization band keep increasing in the“quiet period”of AE. The length，the width and the deformation magnitude of the deformation localization band have little effect on the AE energy and AE ringing counts. The stretching rate and dislocation rate of deformation localization band have a great influence on the AE ringing counts and AE energy，especially the sliding of the deformation localization band has greatest effect.

The meso-structure evolution of coal and granite samples at normal temperature to 350 ℃ was studied by means of on-line heating and synchronous observation. Under the same conditions，the sub meshes with solid particles and pure pores are affected by the temperature more obviously，and the pores are larger. As these pores are throats of porous media，the change of their sizes have a significant effect on the permeability of coal and rock. The permeability of granite and most of the meager coal samples increase first and then decrease with the increase of temperature，while a few meager coal samples show a monotone downward trend. The smaller the coal porosity is，the lower the critical temperature of porosity decreasing. 

The characteristics of crack initiation in rock under far-field tension-compression and biaxial compression loading were analyzed by considering both the singular and nonsingular stress(T-stress) terms at the crack tip. The modified maximum tangential and shear stress criterion was developed for evaluating tensile and shear cracking. The condition of tensile and shear fracture was discussed to further clarify the effect of inclination angle，friction angle，tensile strength and cohesion on fracture types in rock. The results indicate that the nonsingular stress terms have important influence on the near-tip stress field and the modified theory agrees well with experiment. Results with the increment of the friction angle，the shear failure is weakened while the tensile failure is strengthened. However，with the increment of the cohesion or decreases of the tensile strength，the shear failure is strengthened and the tensile failure is weakened.

Saturated fractured rocks in cold regions under cyclic freezing and thawing experience the crack initiation，crack extension，deflection and branching along the crack end，which results in localized damage and fracturing at the crack end and overall failure. The quasi-sandstone samples of similar materials containing a single fracture with the inclination angles of 0°，30°，45°，60°，90°，were prepared. The freezing and thawing cycles of 10，20，30，50 were applied in the experiments respectively. The samples with a single fracture exhibit the localized damage under the cyclic freezing and thawing and the fracture end can be divided into fracture zone，progressive damage zone and systematic damage zone. The localized damage effect becomes weaker and the acoustic wave velocity becomes faster as the increase of the crack dip angle. The bifurcation and deflection of main cracks under cyclic freezing and thawing occur in the samples with a single fracture at the inclination angles of 30°，45° and 60°. The deflection of main crack occurs earlier，the deflection direction tends to be horizontal，and the extended length along the initial fracture direction is shorter as the decrease of the crack tip angle. The localized damages in the upper and lower of crack are different and the macroscopic fracture occurs earlier at the bottom of the crack，and the difference is more notable with the increase of the crack dip angle.

In the fields of nuclear waste landfill，geothermy and deep mining，the effects of temperature on the mechanical behaviors of soft rocks cannot be neglected. A thermo-elasto-plastic model of soft rocks considering structure was proposed based on the super loading yield surface and the concept of temperature-deduced equivalent stress. Compared to the super loading yield surface，only one more parameter is added，i.e.，the linear thermal expansion coefficient. The predicted results and the test results show that the proposed model is capable of describing both the phenomenons of heat-increase and heat-decrease of soft rocks. The stronger the initial structure，the larger the strength of soft rocks. The phenomenons of heat-increase and heat-decrease switch from each other due to the change of the initial structure of soft rocks. Furthermore，no matter whether the heat-increase or heat-decrease，a larger linear thermal expansion coefficient or a greater temperature，always leads to much more rapid dissipation of the structure. When the linear thermal expansion coefficient and temperature are larger at the same time，the dissipation trend will be more obvious. Lastly，the structure dissipates more easily in the case of heat-increase than in the heat-decrease.

The roof structure above goaf is prevalent in mines which use backfill method. Determining the reasonable thickness of the roof under the loads of filling body is important to guarantee the mine safety. The mechanisms of formation and failure of the roof above the goaf under the filling body were analyzed and a mechanical stability model of the roof structure was established to analyze the instability mechanism by applying the cusp catastrophe theory. The expression of the limit thickness of the goaf roof under filling body was deduced according to the sufficient condition and necessary condition of roof structure instability in cusp catastrophe model. The expression was applied to a lead and zinc mine and the safe roof thickness was calculated to be larger than 11.48 m. 12 m was used as the safe thickness and verified in the practical production and numerical simulation.

It has been observed that during an earthquake，the seismic response of slopes could be affected by the topography. Therefore，a general earthquake-induced slope model is defined and designed with five different slope shapes based on the statistical relations between the earthquake-induced landslides and the slope shapes. According to the test results，the amplification factor of the peak ground acceleration(PGA) on the surface of the slope was higher than that in the slope when the intensity of the input motion was relatively high. The site at the upper of the slope with the largest curvature on the middle of the slope surface(AC2) had the most notable amplification effect. The shape of the slope affected the natural frequency of the ground for the slope. The upper convex and lower concave slope had a natural frequency close to 5 Hz while the slopes of other shapes had a natural frequency close to 10 Hz. The critical acceleration values at failure ranged from 500 to 700 Gal，which were consistent with the calculated values for the slope from material strength tests. The shape of the slope affects the location and depth of its failure surface. The slope with large curvature radius(positive for convex and negative for concave) usually has a deeper sliding failure surface. The concave slopes have a shorter sliding distance and a smaller hazardous range. The convex and the upper convex and lower concave slopes have a longer sliding distance and a larger hazardous range. The linear and the upper concave and lower convex slopes have the longest sliding distance and the largest hazardous range. Therefore，the slopes with the linear or the upper concave and lower convex configurations have the highest risks，followed by the convex and the upper convex and lower concave slopes，while the concave slopes have a relatively strong ability to resist the ground motions and pose the lowest danger.

It is important to study the hydrostatic pressure distribution along the structural plane in rock slopes，which is helpful to accurately assess the slope stability and to provide a reasonable suggestion for studying the failure mechanism of this kind of slope. A revised water pressure distribution was proposed to avoid the shortcomings of the traditional assumption of pressure distribution along the structural plane. The hydrostatic pressure distribution is related to the water height in the tension crack，the length of the structural plane and the dip angle. The concepts of the initial hydrostatic pressure and transfer effect are proposed. The transfer effect at each point on the structural plane decreases linearly with the increase of the distance from the point to the start point of the structure plane. The equation for calculating the new hydrostatic pressure distribution is derived and presented in detail. Meanwhile，the equation for calculating the hydrodynamic pressure on the structure plane is also obtained. Finally，the new assumptions and proposed methods are verified based on the analysis of slope stability under the assumptions of different water pressure distributions.

Field tests of applying the I-beam steel arch and the steel grid-concrete core tube supporting structure for tunnels in phyllite and meizoseismal area were conducted. The tunnel is a vital portion of the high speed railway from Chengdu to Lanzhou，adjacent to Songpan town of Aba plateaus，Sichuan Province，and is located in the meizoseismal area of 5•12 Wenchuan earthquake. The settlement of surrounding rock，internal displacement of surrounding rock，pressure between surrounding rock and primary support，internal force of support arch， axial force of rock bolts，pressure between primary support and secondary lining，and strain of secondary lining in two different supporting structures were all measured and analyzed using the methods of field test and numerical simulation. It was suggested that the new type support structure played a significant role to prevent and control the large deformation of surrounding rock in similar geological conditions.

The problem of instability is more prominent when drilling inclined wells in bedding layers. A new wellbore stability model is established considering the weakening action of bedding plane on rocks on the basis of the traditional borehole stability model. The model takes into account the arbitrary nature of 3D in-situ stress with three Euler angles，and applies Mogi-Coulomb criterion to strengthen the effect of intermediate principal stress，as well as combines the single weak-plane strength theory to fulfill the goal of guided drilling. The method and formula for calculating the collapse and fracture pressure using this model are given. The experimental and calculated results show that the rock gains a minimum strength when the angle between the loading direction and bedding plane is 30°.. Mogi-Coulomb criterion is more effective on the estimation of rock matrix strength because of the consideration of the influence of intermediate principal stress. The collapse area is markedly enlarged under the effect of bedding plane，and the collapse position is changed. The drilling direction for obtaining the minimum collapse pressure is not simply perpendicular to the bedding plane in space. And the boreholes in the symmetry in terms of principle in-situ stress plane underground have the same fracture pressure. The safe mud density window calculated with the model above can provide theoretical basis for the safe drilling and trajectory design of inclined boreholes.

法向恢复系数是岩崩块石运动分析的关键参数，其取值直接决定了块石的运动轨迹。为了严格测定花岗岩球砾碰撞的法向恢复系数，分析其影响因素，试验采用自行设计的碰撞试验装置和声频采样技术，精确测定花岗岩球砾碰撞的法向恢复系数，研究球砾大小、碰撞速度、含水状态和板的弹性特性4个因素对恢复系数的影响；并基于弹性接触理论推导出碰撞过程的最大接触应力 、碰撞起裂速度 和碰撞损伤速度vcd，构造接触应力割线变化率 来描述碰撞过程的率相关，分析碰撞法向恢复系数的尺寸效应和速率效应，对碰撞过程耗能机制进行探讨。试验结果表明：花岗岩球砾法向恢复系数存在明显的尺寸效应，低速下更加显著；法向恢复系数的速率效应同样较明显，并且速率效应受球砾尺寸和板的弹性特性影响，呈现较强的相关性；球砾大小和速度相同时，等效弹性模量E?越大，法向恢复系数越小；含水状态对法向恢复系数影响不大。理论分析表明： 和 为控制法向恢复系数变化规律的内在因素；尺寸和速度均是通过改变 和 使法向恢复系数呈现复杂的尺寸效应和速率效应。

Clay rocks have the advantages of low permeability and crack self-sealing ability and are thus chosen as a potential geological barrier for underground disposal of radioactive waste in France and other countries. The high security and long-term requirements of underground radioactive waste disposal require that it is necessary to investigate the time-dependent behaviors of clay rocks. This paper presents the results of a series of one-step creep tests for the purpose of identifying with a relative high precision the creep rate thresholds of the Callovo-Oxfordian argillite with different moistures under the triaxial creep conditions. Three moisture levels are investigated in this paper for complete creep tests. The results show that the creep rate threshold values are related to the moisture and confining pressure. Generally，if the axial creep rate is smaller than 2.5 µε/h，the tertiary creep does not occur. Otherwise，if the axial creep rate is greater than 58 µε/h，the tertiary creep is likely to happen. Although the values between the two thresholds are still questionable，the thresholds are helpful to know in advance whether the tertiary creep would happen.

A method to calculate the long-term and short-term soil displacements and liner stress affected by tunneling in saturated ground was proposed based on the oval deformation mode under two conditions of excavation with or without air pressure. It was observed that the soil deformation curves under the oval deformation mode are in good agreements with the measured values. The excavation under air pressure generates a larger soil deformation than under the non-pressure condition. The long-term settlements in saturated ground are larger than the short-term ones. The variation of the displacement of liner in saturated ground was investigated through parametric analysis. The results show that the maximum negative value of radial displacement of liner occurs at 90° while the minimum one at 270°，which reflects a significant oval deformation trend and overall subsidence. With the increase of the radius and the decrease of the soil moduli，the deformation trend becomes more obviously. The tangential displacement takes the axis of 90°/270° as the boundary axis，and the positive value is obtained at left semicircle while the negative value is obtained at right semicircle. Increasing the radius and decreasing the soil moduli raise the overall level of tangential displacement values. Investigations on the stress of liner through parametric analysis，indicate that the axial force is more likely to present a clear elliptical deformation trend when the tunnel gets stiffer ground or larger gap. The bending moment becomes smaller with the decrease of the depth，the radius and the weight of the soil. The bending moment becomes larger with the decrease of lateral earth pressure coefficient k. The increasing of air pressure results in the rise of the range of compression zone and the values of both positive and negative bending moments.

The sandstone samples with the degrees of water saturation from 0% to 70% were prepared to measure the permeability and porosity under different confining pressures and seepage pressures using the test system for low-permeability rock. The relationship between the permeability，porosity and stress of sandstone samples at different degrees of water saturation were analyzed. The gas permeability of low-permeability sandstones with the degrees of water saturation lower than 50% decreases with the increase of pore pressure. The gas permeability changes with the pore pressure exponentially. With the increasing of the degree of water saturation，the sensitivity of gas permeability to the change of pore pressure decreases，and the sensitivity of gas permeability to the change of pore pressure increases with the increasing of pore pressure. The absolute permeability and the porosity vary with the confining pressure exponentially. With the increasing of the degree of water saturation，the sensitivity of absolute permeability to the change of confining pressure increases，and to the change of porosity decreases. The sensitivities of absolute permeability and porosity to the change of confining pressure decrease with the increasing of confining pressure. The porosity and the absolute permeability correlates positively. A small reduction of porosity can cause a significant decreasing of the absolute permeability. The relationship between the absolute permeability and porosity obeys the index function. The sensitivity of absolute permeability to the change of porosity increases as the increasing of the degree of water saturation. The sensitivity of absolute permeability to the change of porosity also increases with the increasing of porosity.

To improve the recognition rate of microseismic signal with low SNR and the pickup accuracy of P wave in the engineering noise environment，Allen algorithm which can pick up microseismic signal automatically and quickly and Bear algorithm which is good at picking up the microseismic signal with low SNR at the beginning of the P wave were combined to form an AB algorithm with the introduction of Bear weighted factor and characteristic function on the basis of Allen algorithm. The AB algorithm can identify the microseismic signals accurately and accurately pick up the changed P wave automatically. The weighting factor K，characteristic function CF and value of AB algorithm have higher sensitivity to the changes of frequency and amplitude than Allen algorithm. The AB algorithm is more susceptive to the change of amplitude than frequency. The pickup rate of the seismic signal and the pickup accuracy of the automatic P wave in the AB algorithm are better than the Allen algorithm at the project scales. The analysis of the microseismic signal from the deep underground laboratory at Jinping shows that the positioning results of the microseismic sources exhibit higher reliability and stability based on the AB algorithm for the weak signal. The AB algorithm is confirmed to be effective，simple and suitable for the real time monitoring of microseismic signal and the pickup of first arrival of P wave. 

The crack flaws and empty hole flaws were set in a single experiment using the experimental material of PMMA and the new system of digital laser dynamic caustics so that the effects of flaws on the crack propagation in the controlled directional fracture blasting were studied. The results show that the forms of flaws have little effect on the length of blasting induced main cracks. The propagation of main cracks have two stages. In stage I(0–120 μs)，the propagation velocity and stress intensity factor at crack tip decrease rapidly. In stage II(120 μs–crack arrest)，the effects on crack tips caused by stress wave reflected from flaws are more significant，the energy accumulation and stress concentration of crack tips are enhanced，and the velocity and dynamic stress intensity factor increase to a great extent. The peak velocity and peak dynamic stress intensity factor of blasting induced main crack decrease gradually with the curvature increasing of flaw sides during the stage II.

采用极限分析上限法，建立土质边坡坡面沉桩动态稳定性三维计算模型，研究沉桩力、桩土间横向力等对边坡动态稳定性的影响。通过算例计算，对整个沉桩过程中边坡抗滑稳定安全系数的变化规律及其内在机制进行深入研究，并分析桩径、沉桩位置、坡角对边坡抗滑稳定安全系数的影响规律。结果表明：沉桩力对边坡稳定性产生不利影响，导致沉桩前期边坡安全系数持续降低；桩体穿过破坏面后，边坡安全系数由于桩身的抗滑作用而显著提高。桩径越大，沉桩前期安全系数越低，其下降速度也越快，但桩体穿过破坏面后安全系数提升也越明显；沉桩位置越靠近坡顶，沉桩过程中安全系数下降速度越快，导致最危险点的安全系数越低；坡角越大，沉桩过程中整体安全系数越低。分析结果对于坡面沉桩的稳定性评估及设计施工具有一定参考价值。

On the basis of analytical solution of elastic stresses within a semi-infinite plane subjeted to the concentred loading on the surface，a approaching analytical solution is proposed for solving the elastic stress field of an infinite plane containing a single hole with arbitrary convex shape，subjected to arbitrary loading on the inner surfaces. The outer domain of a convex hole of n-polygon shape was divided into n semi-infinite planes. For the surface of every semi-infinite plane，the loadings on the inner surface of the hole is given with the traction to be determined on the extended surfaces into two adjacent semi-infinite planes. An effective iteration procedure is proposed for computing the values of traction on all the extended surfaces successively until the solution is converged，and the elastic stress field of the outer domain of the hole is thus determined. The presented method is simple in principle and computation process. As the computation is based on the analytical elastic solution and the one-dimensional numerical integration of high precision，the final result is approaching the analytical solution. The results of examples show that the stress field of engineering scale thus obtained with the proposed method agrees well with those from the finite element method and complex variable function method，illustrating the effectiveness of the method. The values of stresses in the near field around the hole can be computed as well，with which the generalized stress intensity factor and the order of stress singularity are fitted. The value of generalized stress intensity factor fitted is of high precision and the order of stress singularity is practically equal to the analytical solution in fracture mechanics.

针对洞口管棚受开挖过程影响的特点，考虑初期支护延滞性、围岩应力释放差异性、地层反力系数不均匀性和仰坡坡度等因素，将管棚划分为初支闭合段、初支未闭合段、开挖未支护段、掌子面前方塑性扰动段、弹性扰动段和无扰动段，建立基于Pasternak弹性地基梁理论并考虑施工特性的洞口管棚变形量预测模型。利用有限单元法思想和梁段纵向剪力传递理论，获得管棚变形预测理论值，并应用于桦皮岭隧道工程。结果表明：(1) Pasternak力学模型摈弃了Winkler弹性地基梁不能传递纵向剪力的缺陷，其预测值与现场试验结果吻合度较高，最大偏差较Winkler模型减小11.8 %，更适合洞口管棚变形预测。(2) 管棚变形量随地层反力系数和管棚直径增大而减小，但非线性关系；管棚环向间距与变形呈正比例关系；当地层反力系数和管棚直径超过某一数值，通过调整注浆改善地层反力系数或直径方法来控制管棚变形效果甚微。(3) 在给定变形控制基准下，确定IV，V和VI级围岩不同纵坡条件下经济合理的管棚直径和环向间距，并制定了管棚设计施工参数选择一览表。其研究成果为完善管棚计算方法、设计施工体系提供参考和借鉴。

The consolidation process for foundations with prefabricated vertical drain(PVD) of plate shape is normally analysed with the assumption of the vertical drain to be circular in cross section with equivalent area. Such simplification leads to the discrepancy between the assumed and actual shapes. In this paper，the cross section of PVD was assumed as an elliptic shape which is close to the plate shape. The basic equations of consolidation for the vertical drain under the elliptic cylindrical coordinate system were presented and the degree of consolidation was then obtained. Comparisons between the new and traditional solutions were conducted and discussed. The traditional methods were found to overestimate the drainage effects of PVD. The drainage coefficient of permeability decreases linearly with depth and exponentially with time. The larger well resistance leads to the slower consolidation and even to serious clogging of the drainage board.

In order to solve the problems of the settlement and stability of high-filled slopes，three-dimensional shear tests were carried out to investigate the behavior of unsaturated soil of different dry densities under controlled suction from Yan?an new district. The variations of the deformation and strength of the remolded loess soils were studied. The test results show that the dry density and matric suction influence remarkably the damage form and characteristics of the deformation and strength. The stress-strain relation varies from the strain hardening to the ideal elasto-plastic then to the strain softening as the increasing of dry density. The greater the dry density and suction，the more obvious the dilation and the higher the strength. The cohesion，the friction angle of the suction and the internal friction angle increased with the increasing of the dry density. The friction angle of unsaturated loess soil changes little with the matric suction variation，but the cohesion increases  linearly with the increasing of matric suction. The initial tangential modulus and the volumetric deformation modulus increased with the increasing of the dry density and suction. An expression for strength and a nonlinear model considering the impact of dry density and suction and values of relevant parameters of the soil are proposed for the predictions of the parameters of the strength and deformation of remolded loess soils under different densities and different matric suctions.

In order to reveal the settlement behaviors of high filled embankment and to predict the post-construction settlement，the long-term in-situ monitoring data of a certain high filled loess embankment were analyzed with the FEM computation and the method of layered iteration to inversely predict the post-construction settlement. The results show that the settlement of the embankment itself is the main part of the total settlement and accounts for 63% of the total settlement，while the original ground settlement accounts for 37%. The construction settlement is mainly caused by the compression of the pore air and exhaust consolidation. The uneven foundation and different heights are the main reasons of differential surface settlement.

A new solution for consolidation of composite ground was proposed by adding a quadratic polynomial to the previous solution. The analytical consolidation solution of composite ground considering the effect of two-dimensional well resistance was obtained for granular column under the condition of the additional ground stress varied with time and depth. The solution was compared with the previous simplified analytical expressions. The results show that many previous expressions are the special cases of the solutions deduced in this paper，such as the solution considering the effect of two-dimensional well resistance under the effect of instantaneous loading， the solution considering the seepage and vertical deformation of pile body as well as the Terzaghi one-dimensional consolidation solution，which indicate the correctness and reasonability of the solution obtained. The consolidation rate is increased with the increasing of loading rate and decreased with the increasing of additional stress at the bottom of the ground. The consolidation rate considering the two-dimensional well resistance of the columns is slower than the one considering only the vertical well resistance. The difference of the consolidation rates under the conditions of these two considerations is increased with the decreasing of permeability coefficient of column and the radius ratio of the influence zone to the column. The solution proposed in this paper provides a new idea for solving the consolidation process of composite foundation and contributes to the development and improvement of consolidation theory of composite ground.

This paper studies the improvement mechanism of loess soil modified by the consolid system in comparison with the loess soil modified by cement and lime. The mechanical strength test，disintegration test and flexible-wall permeability test were conducted to measure the engineering property of soil. The water drop penetration time test，X-Ray diffraction test，scanning electron microscope(SEM) test and mercury intrusion porosimetry(MIP) test were carried out to investigate the microscopic properties，such as the surface energy，mineral composition，microstructure and pore filling condition of loess soil. The loess soil modified by the consolid system has higher strength，better durability of slaking and slightly lower permeability. The surface energy of soil particles is reduced greatly and the water repellency ability is obviously better than that of cement or lime modified loess soil. The phase peak groups are basically same in the X-ray diffraction patterns. The silt particle arrangement of loess soil remains unchanged with the increase of consolid system content，but the fine particles coagulate with more adhering material. The volume of large，medium and small pores in loess soil are reduced slightly while the micro pores are increased obviously. The improvement mechanism of loess soil modified by consolid system is that the decrease of surface energy of loess soil enhances the water repellency and water-resisting property，the consolid system reinforces the bonding strength of the microstructure of soil particle skeleton，the weak swelling and pore filling effect of consolid system lead to good permeability of loess soil. Apart from improving the mechanical and hydraulic properties，the consolid system solve the problem of improving the water resistance property and keeping the good permeability of loess soil to some extent.

The field test was carried out to the foundation pit at Mei-zi-zhou river-crossing tunnel on Metro Line of Nanjing Youth Olympic Games. The lattice shaped and conventional diaphragm walls were constructed in the ground with high pressure water at Yangtze River floodplain. The variations of lateral displacement at wall top，the horizontal displacement along wall depth，the surface settlement and the axial forces of supporting with the excavation of foundation pit and time were measured and studied respectively. The lateral displacement at the wall top rebounds after the setup of supporting，which is mainly influenced by the supporting installation，pre-axial force and demolition. The deep lateral displacements at the lattice shaped and conventional diaphragm walls tend to form a ‘bulging belly? shape，and the maximum deep lateral displacement on both kinds of walls can be found in the middle-upper region of the buried depth. In the early stage of pit excavation，there is a slight surface heave in the lattice shaped diaphragm walls，whereas there is no surface heave but a large settlement in the conventional diaphragm walls. However，the ground settlements are gradually decreased with the increase of the distance away from the walls. The differential settlements away from the walls tend to increase in the late stage of foundation pit excavation.