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世界地震工程 2010年第S1期26卷 267-272页

作者：陈育民沙小兵林奔刘汉龙河海大学岩土力学与堤坝工程教育部重点实验室江苏南京210098 河海大学土木与交通学院江苏南京210098

将液化及液化后状态的砂土视为流体状态,研究发现液化及液化后砂土是一种剪切稀化非牛顿流体。对于液化前高孔压状态下的流动特性也值得探讨。根据落球黏度计的原理,开发了饱和砂土液化前流动特性的模型试验装置。在模型箱中铺设饱和砂... 详细信息

将液化及液化后状态的砂土视为流体状态,研究发现液化及液化后砂土是一种剪切稀化非牛顿流体。对于液化前高孔压状态下的流动特性也值得探讨。根据落球黏度计的原理,开发了饱和砂土液化前流动特性的模型试验装置。在模型箱中铺设饱和砂土,模型箱底部与一水箱相连,提高水箱高度可以使模型箱中的饱和砂土产生超孔压。模型箱的砂土中埋设一个可以水平拉动的钢球,通过监测钢球水平运动的速度和所受的阻力来计算砂土的表观黏度,得到饱和砂土液化前高孔压状态下的流动特性。试验中考虑了超孔压比、钢球运动速度对结果的影响。试验表明,饱和砂土在液化前高孔压状态下,表观黏度均随着应变率的增大而减小,呈现出剪切稀化非牛顿流体特性,同时随着超孔压比的提高,表观黏度也逐渐减小。

关键词：砂土液化液化前流动特性试验研究

Dilatancy equation of rockfill material under the true triaxial stress condition

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Science China(Technological Sciences) 2011年第S1期54卷 175-184页

作者： XIAO Yang 1,2,LIU HanLong 1,2,ZHU JunGao 1,2 & SHI WeiCheng 1,3 1.key laboratory of ministry of education for geomechanics and embankment engineering,Hohai University,Nanjing 210098,China 2 Geotechnical Research Institute,Hohai University,Nanjing 210098,China 3 School of Civil engineering and Architecture,Changzhou Institute of Technology,Changzhou 213002,China key laboratory of ministry of education for geomechanics and embankment engineering Hohai University Nanjing China Geotechnical Research Institute Hohai University Nanjing China School of Civil engineering and Architecture Changzhou Institute of Technology Changzhou China

Rockfill material is widely used for construction of high rockfill dam due to its facility,economical cost,high strength and effective aseismatic *** is provoked profoundly to propose a suitable constitutive model for a better application of this *** dilatancy equation of rockfill material plays a significant role in the constitutive *** the sake of simplicity,a dilatancy equation is established by the linear least square method on the basis of the rearranged data of rockfill material in the true triaxial *** on the fact that the rearranged data at different initial confining pressures are aligned in a narrow band,the dilatancy behavior of rockfill material is independent of the initial confining ***,different from the initial confining pressure,both the intermediate principal stress ratio and the specimen density exhibit a remarkable influence on the dilatancy behaviors of rockfill ***,the predictions of the proposed dilatancy equation are in a good agreement with the rearranged test data of rockfill material at different specimen densities and stress paths.

关键词： rockfill material dilatancy equation true triaxial test density stress path initial confining pressure

Dragload and Downdrag Performances of Inclined Pile Group Embedded in Consolidating Soil

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Transactions of Tianjin University 2011年第3期17卷 175-180页

作者：孔纲强杨庆 key laboratory for geomechanics and embankment engineering of ministry of education Geotechnical Research Institute Hohai University State key laboratory of Coastal and Offshore engineering Dalian University of Technology

The performance of inclined pile group embedded in consolidating soil under surcharge load was investigated by experiment in comparison with vertical pile group and single pile under the same conditions; dragload, downdrag, and layered soil settlement were measured. A three-dimensional numerical model was built via FLAC3D software, and verified by the experimental results. Influence factors, such as consolidation time, pile spacing, and pile tilt angle were analyzed. The results show that dragload of inclined pile group increases with the increase of consolidation time and pile spacing or the decrease of pile tilt angle. Downdrag of inclined pile group increases with the increase of consolidation time, pile spacing and pile tilt angle.

关键词： pile group negative skin friction consolidating soil downdrag dragload neutral plane

Macro-micromechanical approaches for non-coaxiality of coarse grained soils

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中国科学：技术科学英文版 2011年第S1期54卷 147-153页

作者： QIAN JianGu 1,2,HUANG MaoSong 1,2 & SUN HaiZhong 1,2 1.key laboratory of Geotechnical and Underground engineering of ministry of education,Tongji University,Shanghai 200092,China 2 Department of Geotechnical engineering,Tongji University,Shanghai 200092,China key laboratory of Geotechnical and Underground engineering of ministry of education Tongji University Shanghai China Department of Geotechnical engineering Tongji University Shanghai China

For coarse grained soils,their principal stress directions may change when the water level of embankment dam varies *** this loading case,the principal directions of stress and strain rate will become *** an effort to model non-coaxial behavior,a modified three-dimensional non-coaxial model is developed in the context of vertex yield(tangent plasticity) *** Element Method(PFC) incorporating user-defined interparticle contact models is also employed to gain an insight into microscopic mechanism of *** analysis focuses on non-coaxial behaviors under simple shear *** has been shown that the proposed non-coaxial model gives good predictions for non-coaxiality with reference to microscopic observations while the classical coaxial model fails to simulate the non-coaxial *** general,non-coaxiality as a result of the rotation of principal stress,is large at a small shear strain,and inclined to become negligible with increasing shear *** coarse grained soils,their non-coaxiality tends to largely depend on the initial normal pressure,where a larger degree of non-coaxiality can be observed at a higher pressure.

关键词： coarse grained soils non-coaxiality particle flow code simple shear

Global analysis on slope stability and its engineering application

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Science China(Technological Sciences) 2009年第2期52卷 507-512页

作者： ZHENG Hong1,2 & ZHOU ChuangBing3 1 State key laboratory of geomechanics and Geotechnical engineering, Wuhan 430071, China 2 China Three Gorges University, key laboratory of Geological Hazards on Three Gorges Reservoir Area, ministry of education, Yi Chang 443002, China 3 School of Civil engineering, Wuhan University, Wuhan 430072, China State key laboratory of geomechanics and Geotechnical engineering Wuhan China China Three Gorges University Key Laboratory of Geological Hazards on Three Gorges Reservoir Area Ministry of Education Yi Chang China School of Civil engineering Wuhan University Wuhan China

In hydraulic engineering, sometimes it is necessary to consider the stability of sliding bodies with lateral frictional boundaries. Neither the existing three dimensional limit equilibrium methods nor the commercial software products are able to treat such situations. The three dimensional factor of safety is accordingly underestimated; while the shearing strength based on the three dimensional back analysis is overestimated. In this study, the lateral boundaries are regarded as the part of the slip surface. Based on the expression of the normal pressure on the slip surface and the patch interpolation, a rigorous solution for the three dimensional limit equilibrium analysis is realized. Meanwhile, the proposed procedure is applied to the stability analysis of the slope with a cable platform on the right bank in Da Gang Shan hydraulic project under construction.

关键词： slope stability the limit equilibrium methods three dimensional problems

A new elliptic-parabolic yield surface model revised by an adaptive criterion for granular soils

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Science China(Technological Sciences) 2010年第8期53卷 2152-2159页

作者： LIU HanLong 1,2 ,XIAO Yang 1,2 ,LIU JinYuan 3 &LI GuoYing 4 1.key laboratory of ministry of education for geomechanics and embankment engineering,Hohai University, Nanjing 210098,China 2 Geotechnical Research Institute,Hohai University,Nanjing 210098,China 3Department of Civil engineering,Ryerson University,Toronto,Canada 4 Department of Geotechnical engineering,Nanjing Hydraulic Research Institute,Nanjing 210014,China key laboratory of ministry of education for geomechanics and embankment engineering Hohai University Nanjing China Geotechnical Research Institute Hohai University Nanjing China Department of Civil engineering Ryerson University Toronto Canada Department of Geotechnical engineering Nanjing Hydraulic Research Institute Nanjing China

An adaptive criterion for shear yielding as well as shear failure of soils is proposed in this paper to address the fact that most criteria,including the Mohr-Coulomb criterion,the Lade criterion and the Matsuoka-Nakai criterion,cannot agree well with the experimental results when the value of the intermediate principal stress parameter is too *** new criterion can adjust an adaptive parameter based on the experimental results in order to make the theoretical calculations fit the test results more *** original elliptic-parabolic yield surface model can capture both soil contraction and dilation ***,it normally over-predicts the soil strength due to its application of the Extended Mises criterion.A new elliptic-parabolic yield surface mode is presented in this paper,which introduces the adaptive criterion in three-dimensional principal stress *** new model can well model the stress-strain behavior of soils under general stress *** to the original model which can only simulate soil behavior under triaxial compression conditions,the new model can simulate soil behaviors under both triaxial compression conditions and general stress conditions.

关键词： principal stress space intermediate principal stress yield surface failure criterion constitutive model

Scattering of SH waves induced by a symmetrical V-shaped canyon: a unified analytical solution

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Earthquake engineering and engineering Vibration 2012年第4期11卷 445-460页

作者： Zhang Ning Gao Yufeng Li Dayong Wu Yongxin Zhang Fei Geotechnical Research Institute Hohai University key laboratory of geomechanics and embankment engineering(Hohai University) Ministry of Education College of Civil engineering&Architecture Shandong University of Science and Technology

This paper reports a series solution of wave functions for two-dimensional scattering and diffraction of plane SH waves induced by a symmetrical V-shaped canyon with different shape ratios. A half-space with a symmetrical V-shaped canyon is divided into two sub-regions by using a circular-arc auxiliary boundary. The two sub-regions are represented by global and local cylindrical coordinate systems, respectively. In each coordinate system, the wave field satisfying the Helmholtz equation is represented by the separation of variables method, in terms of the series of both Bessel functions and Hankel functions with unknown complex coefficients. Then, the two wave fields are described in the local coordinate system using the Graf addition theorem. Finally, the unknown coefficients are sought by satisfying the continuity conditions of the auxiliary boundary. To consider the phase characteristics of the wave scattering, a parametric analysis is carried out in the time domain by assuming an incident signal of the Ricker type. Surface and subsurface transient responses demonstrate the characteristics and mechanisms of wave propagating and scattering.

关键词： SH-wave scattering V-shaped canyon topographic effect wave propagation earthquake ground motion wave function expansion method

Discontinuous deformation analysis based on complementary theory

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Science China(Technological Sciences) 2009年第10期52卷 2547-2554页

作者： ZHENG Hong1,2 & JIANG Wei2 1 China Three Gorges University,key laboratory of Geological Hazards on Three Gorges Reservoir Area,ministry of education, Yichang 443002,China 2 State key laboratory of geomechanics and Geotechnical engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China China Three Gorges University Key Laboratory of Geological Hazards on Three Gorges Reservoir Area Ministry of Education Yichang China State key laboratory of geomechanics and Geotechnical engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan China

The contact between blocks is treated by the open-close iteration in the conventional discontinuous deformation analysis (DDA),which needs to introduce spurious springs between two blocks in contact and to assume the normal stiffness and the tangential stiffness (the penalty factors). Unreasonable values of stiffness would result in numerical problems. To avoid the penalty factors and the open-close iteration,we reformulate the DDA as a mixed complementary problem (MiCP) and then choose the path Newton method (PNM) to solve the problem. Some examples including those originally designed by Shi are reanalyzed,which proves feasibility of the proposed procedure.

关键词： discontinuous deformation analysis (DDA) contact problems open-close iteration complementary theory non-smooth analysis

A Continuum-discrete Hydromechanical Analysis of Seepage Deformation

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A Continuum-discrete Hydromechanical Analysis of Seepage Def...