基于状态参量的饱和砂土剪胀性本构模型

现有的边界面模型多用临界状态区分松砂、密砂,但试验中,很难确定密砂的临界状态.本文以相变线（PTL）为参考线,引入以相变状态为基础的状态参量,将已有的边界面模型加以改进利j用状态参量的概念,可以准确判断砂土在初始时刻和任意时刻的变形趋势,而基于状态参量的剪胀比在相变点处仍等于零.无论是松砂还是密砂,或砂土从一种状态到另一种状态,基于状态参量的剪胀都能真实的模拟砂土的反应.研究结果表明,利用本文的模型参量得到的密砂三轴排水试验,模拟结果与试验结果相吻合,较好地反映了砂土的力学特征.

A dilatancy constitutive model of saturated sands based on state parameter

In this paper,an existing bounding-surface is modified and a state parameter based on phase transformation state is introduced.The deformation tendency of a sand at any time or any conditions can be judged correctly by state parameter.As a result,the dilatancy depends on the state in a way that yields a zero value at phase transformation state.This dependence allows a realistic modelling of the response of a sand in either loose or dense state,or in the transition from one state to another state.A comparison between model simulations and a sequence of experimental results for drained,monotonic loading conditions shows that the simulation results are consistent with the test results,which can better reflect the mechanics characteristics of sandy soil.