不同地基模型对拱坝动力响应的影响

Effects of Different Foundation Model on the Dynamic Response of Arch Dam

在粘弹性人工边界理论基础上,结合波场分解法的地震动输入方法,应用ANSYS软件的参数化语言APDL,编制了模拟粘弹性人工边界和地震荷载输入的程序。针对某碾压混凝土拱坝建立了"库水-拱坝-地基"联合作用的有限元模型,采用施加粘弹性边界并输入相应地震动,讨论了无限地基辐射阻尼的影响,并与无质量地基模型的计算结果进行比较分析。研究结果表明,只有考虑辐射阻尼效应才会得到符合实际情况的坝体地震响应结果,因此实际工程抗震分析时对地基的模拟应该合理选取。

Based on viscous-spring artificial boundary theory and wave field decomposition method of ground motion, the program for simulating viscous-spring artificial boundary and seismic load is developed by using the parametric language function of ANSYS software. Combined with practical arch dam engineering, the finite element model of dam-reservoir- foundation is established. Through implementing the viscous-spring artificial boundary and inputting corresponding seismic motion, the effects of radiation damping are analyzed. Compared with the calculation results of massless foundation model, it is found that the seismic response of dam will be in line with actual situation when the effect of radiation damping is considered. So the foundation model should be reasonably selected in seismic analysis of actual projects.