不同本构模型对计算防渗墙应力的影响

利用平面有限元对某深厚覆盖层上的高土石坝防渗墙进行应力分析，研究防渗墙混凝土采用线弹性本构模型和非线性弹性本构模型时计算的应力差异，并对比了相同防渗墙高度不同坝高和同一坝高不同防渗墙高度下2种模型对防渗墙应力的影响。分析表明，2种本构模型计算的防渗墙应力变化规律相同，但弹性非线性模型计算的应力比线弹性模型计算结果小。在低应力情况下两者计算值接近，在高应力情况下两者计算值差异较大。防渗墙最大应力随坝高和防渗墙高度的增加而增大，2种模型计算的最大应力的相对误差也随着坝高和防渗墙高度增加而显著增大，且呈线性增大趋势。对坝高或覆盖层厚度较大的情况，防渗墙应力较大，宜采用非线性模型进行计算。

Effects of different constitutive models on the calculation of stress of diaphragm wall

Stress of diaphragm wall is analyzed by plane finite element method for high earth-rockfill dams built on deep soil foundation. The differences of stress are studied with two kinds of different constitutive models, i.e. elastic model and nonlinear elastic model, and meanwhile, the influences of the height of dam and diaphragm wall for this two constitutive models are also compared. The results show that, the variation laws of the stress of diaphragm wall are similar for both of the models. But, the stress computed by nonlinear elastic model is much smaller than elastic model does. Under the condition of low stress, the results are similar for the two models, but have big differences for high stress. In addition, for this two models, with the increasing of height of dam and diaphragm wall, the maximal values of the stress are increasing constantly, and relative error of the maximal value of the stress as well, which have the linear relation with the height of dam and diaphragm wall. So, for the conditions of high dams or deep soil foundations, nonlinear elastic model is the right one to use because of the high stress of diaphragm wall.