砂土的物态本构模型

基于砂土的压缩回胀性、剪切非线性及剪缩剪胀性的系统分析和包括循环荷载、主应力轴旋转及应力路径偏转等复杂应力条件下的复杂变形反应，得到了三类应力-应变基本关系。在剪缩剪胀应力-应变关系中，引入了由偏应变分量确定的应变路径长度变量，揭示了应力主轴旋转、应力路径偏转引起的剪缩剪胀性。将这些基本关系与循环荷载下砂土的物态变化相联系，建立了砂土的物态动本构关系。

A physical state constitutive model of sands under cyclic loading

Based on the analysis of the compression, shear nonlinearity and dilatancy of sand and its complicated response under the complicated stress condition including the cyclic loading, rotation of principal stress axis and deflexion of stress path; three kinds of stress-strain relation are obtained. They are described by a relationship between effective mean normal stress and compressive volume strain, a relationship between deviatoric stress and deviatoric strain and a relationship between effective stress ratio and dilatancy strain ratio respectively. Through the increasing length in deviatoric strain path determined by the component in deviatoric strain space, the positive and negative dilatancy can be obtained under rotation of principal stress axis or deflexion of stress path. Developing the essential stress-strain relations under cyclic loading, a physical state dynamic constitutive model of sand is establisbed and related to its change in physical states.