A Comprehensive Seismic Slope Stability Assessment of Earth Dams

Abstract

The need for services to the global community has necessitated the construction of earth dams in seismic vulnerable zones. Earth dams serve agricultural, industrial and drinking purposes and their stability against seismic forces is a critical aspect. Seismic slope stability analysis of earth dams needs to addressed carefully to ensure safety against earthquake. The present study deals with numerical analysis of zoned earth dams with different geometrical sections subjected to seismic excitations. The effect of provision of filters, drains, cutoff trenches and berms in the dam geometry on the seismic response have been studied. The influence of above provisions on the seepage losses, seepage paths and stability of slopes are documented for extreme cases such as end of construction, reservoir full and sudden draw down conditions. Further, the most stable model obtained from slope stability analysis is subjected to time history analysis and Newmark deformation analysis. From the results, a comparison is made between dam with a central core section and upstream inclined core section. Further, the stability of the filter and drain sections of the dam against liquefaction susceptibility are explored.