The Development of Multiple Seepage Faces on Layered Slopes

Abstract

This study provides an analysis of the water table configuration and hydraulic‐head distribution in layered hillsides. A finite‐element model was used to simulate two‐dimensional, saturated‐unsaturated, steady state flow through layered slopes. A laboratory sand tank experiment was used to verify the physical foundation of the mathematical model. It is shown that layered slopes feature multiple seepage faces, perched water tables, and wedge‐shaped unsaturated zones. The hydraulic‐head distribution and water table configuration are strongly dependent on the position of the impending layers and the ratio of the hydraulic conductivity between adjacent layers. This work has geotechnical implications with regard to slope stability and the control of groundwater inflows into excavations. It has hydrogeological implications with regard to flow path analysis in contamination studies. It has geomorphological implications with respect to landform development by mass movements and surface water erosions, and to drainage network development through piping.