基于广义热力学改进的超固结黏土本构模型

A Constitutive Model for Over-consolidated Clays Based on Generalized Thermodynamics Improvement

统一硬化模型假设体积塑性功一半耗散,一半储存。如果定义同一回弹线与等向压缩线和临界状态线交点对应的有效体积应力比值为间隔应力比,则统一硬化模型间隔应力比为2,但不同土的间隔应力比并不总是为2。基于广义热力学理论,引入间隔应力比对塑性功的耗散和储存进行重新分配,提出了一个基于统一硬化参数改进的超固结土本构模型,并通过与饱和藤森黏土三轴压缩和拉伸试验进行对比,验证了模型的有效性。

Unified hardening model assumes that volumetric plastic work being dissipated is equal to which is stored.If the ratio of the effective volume stress corresponding to the intersection of the same unloading/reloading line with the isotropic consolidation line and the critical state line is defined as the spacing ratio,the spacing ratio of the unified hardening model is equal 2,but the spacing ratio of different clays is not always 2.The spacing ratio is suggested to describe the ratio of volumetric plastic work to plastic free energy.Based on generalized thermodynamics and unified hardening parameter,an improvement constitutive model for over-consolidated clays is proposed.The rationality of the model is verified by comparing the proposed model calculation results with the triaxial compression and stretch experimental results for Fujinomori clay.