包含Reynolds剪胀的砂土热力学模型

首先简要介绍了建立弹塑性本构模型的热力学方法,它不仅具有紧凑的数学结构,而且自动满足热力学定律.基于砂土变形的微观力学机制,将砂土的塑性体积应变增量分 为"应力诱发的体积应变增量"和"剪切应变诱发的塑性体积应变增量"(即Reylonds剪胀)两部分,自然地将与Reylonds剪胀相关的零功约束引入到弹塑性土体模型的热力学超塑性公式中,建立了包含Reynolds剪胀的砂土热力学模型.基于前人的试验结果与理论分析,建立了固结压力与应力诱发的剪胀角的硬化定律,通过对两种砂土试验数据与预测结果的对比分析,验证了模型的有效性.

A Thermomechanical Model for Sands Including Reynolds Dilatancy

The thermomechanical procedure of establishing elastic/plastic constitutive model for geomaterials is introduced briefly.The major attraction of this approach is that it not only provides a tight mathematical structure,but also satisfies the laws of thermo-dynamics automatically.Based on the deformation micro-mechanism of sands,the plastic volumetric strain rate is decomposed into two parts: stress induced volumetric strain rate and shear strain induced volumetric plastic strain rate,i.e.the Reynolds dilatancy.So the zero work constraint,associated with Reynolds dilatancy is incorporated into the thermomechanical hyperplastic formulation of elasto-plastic soil models in a natural way,then a thermomechanical model of sands,which includes the Reynolds effect and automatically leads to the development of anisotropy,is established.From other author's tests and theoretical analysis,the hardening laws for the consolidation pressure and the induced dilatancy angle is given.After the comparison of tests data and predicted results of two sands,it is shown that the results are satisfying and the model is available.