考虑中主应力效应Gudehus-Bauer亚塑性模型的改进

Modification of Gudehus-Bauer hypoplastic model considering medium principal stress

针对Gudehus-Bauer亚塑性模型不能考虑中主应力影响,在Gudehus提出的响应包络线理论基础上,提出了在模型的非线性项乘以一个考虑中主应力的因子进行改进.这种改进增加了土体剪切时的强度,改变了土体受压时的变形.新模型对中主应力的变化在中主应力参数影响程度能够有一定反映.同时将改进后的模型与中主应力参数为常量的真三轴实验进行了比较.结果表明改进后的模型可以模拟中主应力对砂土强度和变形特性的影响,能够定量预测由于中主应力影响产生的体积应变.

Gudehus-Bauer hypoplastic model can not consider the effect of ＆medium principal stress, so it is modified through multiplying its nonlinear term by one factor that considers medium principal stress based on Gudehus＇ s response envelope theory. This modification enhances the shear stiffness of soil and changes the compression deformation of soil. The modified model can reflect the effect of medium principal stress change on the medium principal stress parameter, and it is compared with the true triaxial test taking the medium principal stress parameter as constant. It is shown that the modified model can simulate the effect of medium principal stress on strength and deformation of sand and predict the volumetric strain caused by medium principal stress quantitatively.