基于DDA和FEM耦合方法的碾压混凝土坝抗震安全性分析

Seismic stability analysis of rolled compacted concrete dam based on approach of DDA coupled with FEM

应用非连续变形分析(DDA)和FEM耦合方法研究了碾压混凝土重力坝的动力反应.研究了DDA与FEM耦合算法以及四边形网格自动生成算法,开发了DDA与FEM耦合算法分析程序,并对一碾压混凝土重力坝的动力特性和抗震安全性以及不同的地震动输入对坝体破坏形式的影响进行了详细计算.结果表明:(1)在静力荷载和设计地震动作用下,大坝混凝土各层面保持很好的连续性和整体性,大坝是稳定的、安全的;(2)碾压混凝土大坝的破坏一般发生在上部,由于坝体上部的碾压层面出现张开、滑移等现象,引起层面的抗滑能力下降,最终导致大坝破坏;(3)不同的地震动输入对大坝的动力反应和破坏形态有很大的影响.

Comprehensive research on the dynamic responses and the failure process of a high RCCD are performed using the discontinuous deformation analysis (DDA) coupled with finite element method (FEM). Some additional functions have been incorporated into the current DDA code, including coupling algorithm of DDA and FEM and an improved four-node isoparametric element generator for deformable elements. The corresponding program is developed based on the MS-WindowsTM computing environment. The results show that RCCD is safe under the design loadings. Furthermore, the ability of over loading and the failure mode are calculated and discussed. The results demonstrate that the failure of the RCC dams usually occurs at the top of the dams and the opening and sliding between the RCC layers will cause the failure of the RCC dams, and the effects of different earthquakes input on the dynamic response behaviors and the collapse pattern of the systems are significant.