Seepage Charts for Homogeneous and Zoned Embankments

Abstract

The writer presents seepage charts for calculating the quantity of flow Q and critical points on the phreatic surface, A and B, for homogeneous and zoned embankments on an impervious foundation. The charts are basically a practitioner's tool for rapidly estimating seepage quantities for both homogeneous and zoned embankments. The charts will also aid in the actual flownet construction. The charts were developed from a computer program developed by the writer using the method of fragments. In comparison to flownet solutions, the charts give an average error for seepage quantity of +5%. For points on the phreatic surface A and B), an average error of -8 and +4%, respectively, are attained. Input variables are upstream and downstream core slopes, downstream shell slope, permeability of core and shell, pool elevation, and crest width. A method is also presented to estimate the seepage quantity for upstream sloping core embankments.