库水位下降期土坝饱和——非饱和渗流的二维数值分析方法

Two-dimensional numerical analysis of saturated-nonsaturated seepage through earth dam during reservoir drawdown

本文提出一种计算土坝饱和——非饱和渗流的数值分析方法。该方法采用4节点等参元及三角形单元离散饱和——非饱和渗流域,用伽辽金有限元法结合隐式、向后差分法求解渗流控制方程。编有计算程序,可方便地用来计算库水位下降期土坝的非稳定渗流。文中对唐山陡河土坝进行了实例计算,并把计算结果同现场观测结果进行了比较。

This paper presents a numerical analysis method for evaluating the saturated-unsaturated seepage in earth dam. In this method, the saturated-unsaturated seepage domain is dis-cretized into isoparametic elements with four modes and trianglar elements. Galerkin's finite elementmethod combined with the implicit backward difference is applied to solving the seepage governingequation. The program for computation has been composed and therefor can be conveniently em-ployed to evaluate the unsteady seepage flow in earth dam during reservoir drawdown. ln this paper,the seepage analysis on the Douheba dam, Tangshan, has been performed as an example and a com-parison has been made between the results of calculations and field observations.