Slope Stability Analysis in Embankment Dam Under Static Condition Using Numerical Model (Case Study: LegeamaraEarthen Dam)

Abstract

Slope stability is now the most important factor in determining the overall safety of earthen dams. The primary goal of this study was to  assess the slope stability of the Legeamara earthen dam found in South Wollo, Ethiopia. The GeoStudio software was used to analyze the  slope stability safety factors using SLOPE/W in various operational scenarios. In this study, the slope stability analysis for each state and  each slope with American Crops Engineer #1 and #2, Ordinary, Bishop, Jambu, Morgenstern-Price, and Spencer methods, calculated that  the minimum factor of safety in each of those methods, being considered as a safety factor of slope stability. The three different loading  conditions were analyzed i.e., end of construction (upstream and downstream slope), steady-state (upstream and downstream slope) at  EL 2449 m, and rapid drawdown (upstream and downstream slope) with a minimum factor of safety 2.09,1.93, 2.07, 1.35, 2.14 and 1.91  respectively from all methods of Limit Equilibrium slope stability analysis. Using the recommended dam design standards bythe United  States Army Corps of Engineers (USACE) and the British Dam Association (BDS),the slope stability analysis of the Legeamara earthen dam  is safe at all critical load conditions. And, it is found that Legeamara dam is able to withstand stresses at all load conditions as the  minimum factor of safety lies between (2.098-2.246) and (1.93-2.003) in upstream and downstream, respectively.