岩土工程学报Issue(5)：776-783,8.DOI:10.11779/CJGE201505002
球应力和偏应力对粗粒土变形影响的真三轴试验研究
True triaxial tests on influence of spherical and deviatoric stresses on deformation of coarse-grained soil
摘要
Abstract
In order to study the influence ofp,q andθσ on the deformation of coarse-grained soil, several tests in which only one of the three variables changes while the other two keep constant are performed on coarse-grained soil by using the TSW-40 type true triaxial apparatus in Hohai University. The results show that ifp decreases with constantq andb, few deviatoric strain but some volumetric dilation will be generated at the preliminary stage. With the decrease ofp, the volumetic dilation increases, which causes the increase of deviatoric strain that is smaller than the volumetric strain in absolute value. Later both the volumetric strain and the deviatoric strain will be accelerated until failure. It indicates that the decrease ofp induces the volumetric dilation immediately, which loosens the particle structure, and then the deviatoric strain will be generated. Ifq increases with constantp andb, little volumetric dilation but some deviatoric strain will be produced at the preliminary stage. With the increase ofq, the deviatoric strain increases, which causes the increase of the volumetric dilation that is smaller than the deviatoric strain in absolute value. Later both the deviatoric strain and the volumetric strain will be accelerated until failure. It demonstrates that the increase of q induces the deviatoric strain directly which causes particle dislocation, and then the volumetric dilation will be produced. If θσ changes with constant p and q, some but very small unrecoverable volumetric and deviatoric strains will be generated. Two parameters sp (sp =(p/q-p0/q0)/(1/Mf-p0/q0)) and sq (sp=(q/p-q0/p0)/(Mf-q0/p0)) are introduced, in which p0 and q0 are the initial spheric stress and the deviatoric stress respectively, Mf is the stress ratio at failure. The test results show that when p decreases with constant q and b, dεv/dp and 1/(1-sp)1/2-1 are in direct proportion; dεs/dp and -sp[1/(1-sp)1/2-1] are in direct proportion; stress-dilatancy equation is dεv/dεs= -1/sp. When q increases with constant p and b, dεs/dq and 1/(1-sq)1/2-1 are in direct proportion; dεv/dq and -sq[1/(1-sq)1/2-1] are in direct proportion; stress-dilatancy equation is dεv/dεs= -sq. Finally the characteristics of the flexibility matrix of coarse-grained soil are analyzed according to the test results.关键词
粗粒土/真三轴/应力应变/柔度矩阵Key words
coarse-grained soil/true triaxis/stress-strain/flexibility matrix分类
建筑与水利引用本文复制引用
施维成,朱俊高,代国忠,卢曦..球应力和偏应力对粗粒土变形影响的真三轴试验研究[J].岩土工程学报,2015,(5):776-783,8.基金项目
国家重点基础研究发展计划（973计划）项目（2013CB036404）；住房和城乡建设部科学技术计划项目（2012-K3-9，2012-K3-23）；江苏省前瞻性联合研究项目（BY2014039）；江苏省六大人才高峰项目（JZ-011）；重庆交通大学水利水运工程教育部重点实验室暨国家内河航道整治工程技术研究中心开放基金项目 （）
