An extended pressure application for transient seepage problems with a free surface

In this paper, a new finite-difference-solution technique for solving transient seepage problems with an unknown free sur ace has been proposed. The governing finite-difference equations were derived using flux conservation in the general case of anisotropic and nonuniform permeabilities and variable grid spacing, and these equations were modified by the extended pressure (EP) method Transient seepage problems may be easily solved by the proposed solution technique, which is based on an iterative spreadsheet calculation. The technique was illustrated by several free-surface seepage problems analyzed previously by several researchers, and good agreement was obtained.