Effect of Ground Water Level and Seismic Intensity on Failure of a Slope

Abstract

Analysis of stability of a slope becomes important to predict the failure of a natural or manmade slope. Among several factors which trigger failure of a slope, earthquake in presence of groundwater may be quite significant. This paper studies the failure of embankment slopes under different seismic conditions with variable groundwater levels. Three embankments of different heights have been considered and their analyses have been performed by varying slope angle, embankment soil properties, and groundwater levels. The current study contains probabilistic approach of slope stability by assigning an uncertainty range of density and shear strength parameters of embankment soil. Thus the current study considers input variables like height and angle of slope along with three soil properties: bulk density, cohesion, and angle of internal friction of embankment soil. In each case three groundwater levels have been considered. Out of all these variables 50 numbers of random variables for each of bulk density, cohesion, and angle of internal friction of embankment soil have been generated within some specified uncertainty bound with the help of Monte Carlo simulation. Finally, results have been presented in the form of variation of factor of safety with slope geometry and seismic intensity levels for different positions of groundwater levels. The study finds different slope geometry and seismic conditions along with variable groundwater levels affecting the outcome of slope stability analysis quite substantially.