本构模型对黏性土侧向卸荷路径下应力应变关系适用性研究

为研究侧向卸荷应力路径对黏性土应力应变特性的影响，首先介绍了2种典型的修正邓肯张模型和三参数模型，然后分析比较了这3种模型反映侧向卸荷应力路径条件下土体应力应变特性的能力。即分别利用这3个模型模拟普通三轴侧向卸荷条件下的试验结果，得到相同条件下各种模型的应力应变特性曲线。并与试验结果进行对比发现：3种模型均能在不同程度上反映侧向卸荷应力路径对黏性土应力应变特性的影响，其中修正3的效果更明显一点，3种模型存在一定的联系，即参数值达到特定的情况时3种模型退化成为同一模型。

Research of constitutive models reflecting stress-strain relationship in lateral unloading conditions

To study which elasticity nonlinear model can reflect the effect of lateral unloading stress path on the relationship of stress and strain of clay, two typical modified Duncan Chang models and Wang wei's 3 parameter model were introduced and then the three models analyzed and compared. These three typical models were used to simulate the relationships of stress and strain of lateral unloading experiment and thus stress strain relationships obtained. The simulation results were compared with the results of lateral unloading experiment, which demonstrates that the three models can reflect the behavior of stress and strain of clay subjected to lateral unloading stress path, and the results of 3 parameter model are better. And in certain circumstances, it can be found that the three models are the same.