高土石坝抗震分析得到国内外学者的极大关注。采用土工离心机振动台模型试验和动力数值模拟技术相结合的复合模型方法来研究高心墙堆石坝地震反应特性。首先对不等比尺的离心模型试验结果进行数值模拟,以验证数值计算模型和确定计算参数,然后用数值方法对离心模型试验结果进行拓展和外延,推广到等比尺和原型情况。对比分析了高心墙堆石坝地震加速度放大系数、地震残余变形、防渗墙动应力和破坏模式。计算值与试验值变化规律一致,表明复合模型是研究高心墙堆石坝地震反应特性一种行之有效的方法,(40~50)g离心机振动台模型试验基本上可以反映高土石坝的地震反应特性。
The aseismic analysis of high earth-rockfill dams has been widely concerned.The combined model method of dynamic centrifuge modelling tests and dynamic numerical simulation is used to study the seismic responses of high core rock-fill dams.Firstly,the results of dynamic centrifuge modelling tests with different scales are simulated numerically.The calculation model is examined and verified,and the relevant parameters are determined.Then,the results of dynamic centrifuge modelling tests are extended to those of the dynamic centrifuge modelling tests with equal stress and prototype by means of numerical method.The amplification coefficient of accelerations,residual deformation of dams,stress of concrete diaphragm walls and mode of failure of high core rock-fill dams are compared and analyzed.The numerical results are in agreement with the test ones.It is indicated that the combined model and the dynamic centrifuge modelling tests with 40g ~50g can be used to study the seismic responses of high earth-rockfill dams.