Influence of drainage condition on Coulomb-type active earth pressure

The present paper focuses on the computing of Coulomb-type active earth pressure acting on a retaining wall provided with a drainage system or without and supporting a soil mass subject to steady water seepage. The influence of drainage conditions on the critical inclination of the failure surface and the coefficient of active earth pressure is investigated by discussing their variations with increasing effective internal friction angle of the soil mass. The results indicate that when the soil effective internal friction angle is increased, the critical inclination increases, but the coefficient of active earth pressure decreases. It is better to provide the drainage at the base of the backfill as well as at the bottom of the wall base rather than providing the drainage along the vertical face of the wall. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 5–8, September–October, 2008.