不同库区水位下坝基地震液化的有效应力分析

Effective Stress Analysis of Earthquake Induced Liquefaction of Dam Foundation under Different Water Table in Reservoir

采用基于有效应力的完全耦合动力分析方法和Cyclic mobility动力本构模型,以某水库大坝作为工程实例进行分析,讨论在设计水位和死水位情况下坝基的地震液化可能性.计算结果表明,Cyclic mobility本构模型可以很好地模拟饱和砂土的液化.通过分析可以得出如下结论:在死水位情况下坝基的液化区域较设计水位情况下减少,但由液化所引起的上游变形明显增大,因此设计时需要对此引起注意.

The earthquake induced liquefaction of dam foundation was analyzed using an effective-stress based, fully coupled dynamic analysis method, in which the behavior of the sandy soil is described by means of a cyclic mobility constitutive model. The paper is primarily concerned with different responses under design water table and dead water table in a reservoir. The results show that the cyclic mobility constitute model can reflect the dynamic response of liquefiable soils, and that the liquefaction zone under dead water table decreases compared with the case of design water table, but the liquefaction induced deformations increase obviously in the upstream.