摘要
认为岩土介质变形中出现的剪胀现象实质上是一个损伤过程.通过中密砂的三轴压缩试验,发现其在剪胀后,弹性模量和剪切模量大幅度下降,这进一步证实了剪胀的确是个损伤演化过程.引进了一个损伤变量描述这个过程,结果表明,损伤程度相对塑性体积应变的变化速率与初始固结压力相关,且随压力增大而减小.同时利用数值建模方法建立了砂土的弹塑性-损伤模型,考虑了弹塑性变形与损伤的耦合效应,获得了相应的应力应变关系及它的三维曲面.
It is considered that the dilatancy occurred in the deformations of rock and soil is essentially a process of damage. Through the tests of triaxial compression for medium sand, it is found that the values of elasticity and sheer modulus obviously decrease after dilatancy, which verifies that the dilatancy is a process of damage indeed. A variable of damage is introduced to describe the damage evolution. The analytical results show that the rates of damage degree relative to the plastic volume strain depend upon the initial pressure of consolidation P_0, and decrease with the increase of P_0. In addition, the elastoplastic-damage model, in which the coupling between elastoplastic deformation and damage is considered, is built by utilizing the numerical method in modeling constitutive relations for rock and soil. The stress-strain relation and its three-dimensional surface are obtained.
出处
《华中科技大学学报（城市科学版）》
CAS
2005年第1期63-65,共3页
Journal of Huazhong University of Science and Technology
关键词
损伤
应力路径
数值建模
本构关系
剪胀
damage
stress path
numerical modeling
constitutive relation
dilatancy
