UBC Theses and Dissertations
The development of multiple seepage faces along heterogeneous hillsides Rulon, Jennifer
A study has been made to clarify the water-table configuration and hydraulic-head distribution in layered hillsides containing multiple seepage faces. A finite-element model was used to simulate two-dimensional, saturated and unsaturated, steady-state, and transient flow through layered slopes. A laboratory sand-tank experiment was built to test the physical foundation of the mathematical model; the test met with success. Layered slopes were found to feature perched water tables and wedge-shaped unsaturated zones which, in some cases, can extend several kilometers into the flow region. The results demonstrate that the hydraulic-head distribution and the formation of multiple seepage faces are strongly dependent on the position of the impeding layers, the hydraulic conductivity contrast, the rainfall rate, anisotropy, and the slope angle. Predictions of the groundwater conditions based on homogeneous, saturated analyses may be significantly in error when applied to problems in layered slopes. This study has implications with respect to slope stability, inflows into excavations, regional groundwater flow, the occurrence of perched flow systems, and hillslope processes involved in landform development.
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