ANALYSIS OF SEEPAGE IN GRAVITY DAM

Abstract

Uplift pressures, caused by water seeping through or under a gravity dam, play an important role in the stability of a gravity dam. In order to reduce the uplift pressures, vertical porous concrete drains/formed drains are provided in the body of the darn spaced along the dam axis. In the present study analytical solution for deter-mining uplift pressures in a gravity darn within a system of equally spaced drains of uniform diameter, has been obtained. The solution is based on Darcy's law of see-page and the conformal mapping technique using Schwartz-Christoffel transformation. The theory developed on this basis takes into account the size of the drains, their spacing along the dam axis and position from. the upstream face of the dam. An expression for average uplift pressure has also been derived and results presented in the form of graphs.