Evaluation of Different Design Options Impact on Seepage and Stability Analysis of Golfaraj Dam

Seepage in earth fill dams is one of the important factors that may cause the erosion and slope instability if it is ignored. Therefore, it is crucial to calculate the leakage discharge through the body of dam and foundation, to prevent economic and life hazards by considering technical and economical issues. In this research, the seepage analysis of the body and the stability of the upstream and downstream slopes of Golfaraj dam after construction, during steady state seepage, rapid drawdown of reservoir and OBE, MCE earthquakes have been investigated and compared by applying different limit state equilibrium methods including: Spencer, Bishop, Janbu, and Mohergenstren-Price, using built-in Geo studio software. The results showed that seepage discharge in a deep section without dike was 18.2 m3day-1 per unit width which was reduced in the case of applying a cutoff or a concrete blanket by 95 and 10 percent, respectively. Data obtained from the slope analysis indicated that the slope was stable under any circumstances and the limit equilibrium methods were convergent.