A variably saturated numerical model for seepage and stability analyses of an embankment dam with a central core

Abstract

Seepage and slope stability analyses are prerequisites for the safe design of embankment dams. In the present study, a variably saturated numerical flow models is developed for seepage and stability analyses of an embankment dam with a central core. The numerical model solves the variably saturated unsteady state seepage through a vertical section of the dam by fully implicit finite difference scheme. The pore water pressure obtained from the seepage analysis is employed to compute the downstream slope factor of safety under full reservoir condition and upstream slope factor of safety under sudden drawdown using modified Bishop's method. The seismic effects on the stability of both upstream and downstream slopes is carried out using Pseudo Static approach. It is observed that the saturated hydraulic conductivity has significant effect on the factors of safety of both upstream and downstream slopes. Further, it is found that the seismic effects reduce the factors of safety of both upstream and downstream slopes significantly at higher values of saturated hydraulic conductivity of the core material.