为了研究淤砂层对高坝地震反应的影响,建立了重力坝库水淤砂地基系统动力分析的二维时域显式有限元模型,其中将淤砂层模拟为液固两相介质,并严格考虑了坝体、库水、淤砂层和地基间的动力相互作用。该模型的特点在于不同类型介质都以位移向量为未知量,采用时域显式逐步积分方式求解,不需要求解联立方程,因此节省计算时间和内存,可以非常方便地用于坝体线性和非线性动力反应分析。文中还应用所建立的模型,分析了淤砂层饱和度及厚度对坝顶加速度反应的影响,结果表明淤砂层可能会对坝体反应产生重要影响。 In order to study the effect of silt layer on the seismic response of high dam, a two-dimensional time-domain explicit finite element model for dynamic analysis of silt sand foundation system of gravity dam is established. The silt layer is simulated as a liquid-solid two-phase medium The dynamic interaction between the dam, reservoir water, silt sand and foundation is strictly considered. The model is characterized by different types of media with displacement vectors as unknowns, time-domain explicit step by step integration solution without the need to solve the simultaneous equations, thus saving calculation time and memory, which can be very conveniently used for dam linear and Nonlinear dynamic response analysis. The model was also used to analyze the effect of silt saturation and thickness on the acceleration at the crest. The results show that the silt layer may have an important impact on the dam response.