Accepted July Y. Zhang. DV Griffiths.

Based on the method of fragments for the analysis of steady confined seepage, a customized type E fragment is developed, with results presented in the form of charts for the estimation of seepage quantities and exit gradients under embedded waterretaining structures with a vertical cut-off wall. The type E fragment is shown to be an extension of previously derived type A and type D fragments, allowing for both embedment and a cut-off wall. The charts are generated using finite element analysis and cover both isotropic and anisotropic permeability cases. Validation of the fragment is confirmed by comparison with existing method of fragments and full finite element analysis. The charts are shown to predict the flow rate and exit gradient more precisely than existing methods of fragments. The design charts presented in this paper cover a wide range of confined flow problems of practical interest.

Automated summary

In this study, a new analysis tool is developed based on the method of fragments for the analysis of steady confined seepage. It allows for the estimation of seepage quantities and exit gradients under embedded water-retaining structures with a vertical cut-off wall. The tool, presented in the form of charts generated using finite element analysis, is shown to predict the flow rate and exit gradient more precisely than existing methods of fragments, and covers both isotropic and anisotropic permeability cases.