Active earth pressure due to soil mass partially subjected to water seepage

A method for determination of the active earth pressure exerted by a cohesionless backfill, subjected to water seepage from a high water table, on a retaining structure is presented. The method comprises a numerical procedure based on the boundary element method (BEM) for the seepage analysis and a trial wedge method for the limit equilibrium analysis. The numerical results of the seepage analysis are presented as normalized charts that can be used in the trial wedge method without recourse to the BEM computer code. The main benefits of the proposed analysis are the simplicity of use and the small amount of data necessary. For the seepage analysis, only the phreatic line exit point height at the retaining structure face is required. Numerical results obtained for a proposed example of a retaining wall show the influence of the water seepage on the active earth pressure. The analysis method also can deal with cases of soil anisotropy with respect to the permeability.