考虑土体结构性的弹塑性硬化模型

在对人工制备结构性土样等应力比压缩试验结果分析基础上,确定出结构性土体初始屈服面形状和土体初始屈服后塑性应变增量的方向,推导出结构性土体屈服函数的表达式;硬化参数采用塑性功的函数,根据三轴排水剪切试验结果确定出土体的硬化规律。由此构建能反映土体结构性的弹塑性硬化本构模型,并用试验进行了验证。本文提出一种基于试验的建模方法,不依赖经典塑性力学理论的正交流动规则,并建立可考虑土体结构性影响的本构模型,对土体结构性研究具有借鉴意义。

An Elasto-plastic Hardening Model for Structured Soil

Based on compressive tests of different stress paths,the initial yield curve of structured soil can be derived from the yield stresses of certain stress paths,as well as the direction of the increment of plastic strain after yielding,and from this the yielding function of the structured soil can be deduced.In addition,the hardening law,which uses the function of plastic work Wp as a hardening parameter,can be used in accordance with the results of triaxial drained tests.An elasto-plastic hardening model that simulates the effect of the soil structure is proposed,and this model is verified by the test data.Based on the test data,a constitutive model is presented that simulates the effect of the soil structure and does not use the normality law presumption.These results have important theoretical significance for structured soil research.