عنوان مقاله [English]
Seepage is one of the main threats to the stability of the earth dam, which can weaken the dam structure and cause piping, washing the earth dam materials inside the body or foundation and eventually its failure. In this study, seepage analysis of Kamal-Saleh earth dam was performed using Seep/W software under three conditions of steady-state, rapid drawdown and end of construction for the current dam as well as for increased spillway level in stable seepage condition. The effect of increasing the height of spillway on the seepage rate inside the body and foundation of the dam, hydraulic gradient and phreatic surface was investigated. To evaluate the dam behavior in the conditions of increasing reservoir capacity, seepage analysis was performed for the current level and increased levels of spillway by one-meter intervals. According to the software results, the dam was safe against seepage in the current spillway level in every three conditions and provided the required factors of safety. In the conditions of increased spillway level, the amounts of seepage and the hydraulic gradients increased and the factors of safety against boiling decreased in a way that by increasing the dam spillway level equal to 4 meters, the seepage through the dam body and foundation increased 85% and the safety factor against boiling decreased 4.5% but in all these conditions, the dam was safe against boiling. In the current and increased levels of the spillway, there are the appropriate similarity of phreatic lines produced by the selected analytical method and Seep/W. The most similarity is seen in the upstream shell and core and the maximum difference is seen in the phreatic line intersection with the downstream slope of the dam.