初始应力各向异性土的弹塑性模型

An elasto plastic model for soil with initially stress induced anisotropy

剑桥模型沿球应力轴 ( p轴 )等向塑性体变硬化 ;在日本广泛采用的关口—太田模型沿初始固结线 (K0 线 )不等向塑性体变硬化。三轴试验数据表明 :自K0 状态向伸长方向剪切时 ,前者方法计算的体积应变偏小 ,而后者方法计算的体积应变偏大。作者提出一种介于上述两者之间、考虑初始应力各向异性 (如K0 固结 )的不等向塑性体变硬化弹塑性模型。为了使模型在三维应力下较好地反映土的强度和变形特性 ,模型的剪切屈服准则使用SMP准则。模型的土性参数与剑桥模型一样 ,其预测值与粘土实测值的比较表明 ,提出的模型是简单合理的 。

In this paper, an elasto plastic model is proposed for soil with initially stress induced anisotropy. The hardening axis in the presented model is between the axes of the Cam clay model and the Sekiguchi Ohta model. A transformed stress based on the SMP criterion is used for making the model become a reasonable three dimensional model. Comparisons with experimental data from drained shear tests on K 0 normally consolidated clay in different stress paths show that the proposed model gives excellent predictions. Therefore, the model is more realistic than the Cam clay model or the Sekiguchi Ohta model in predicting the deformation and strength of soils.