Performance Assessment of Shirin Earth Dam in Iraq Under Various Operational Conditions

Proper dam management should be ensured regularly to avoid breaches and failure. In this study, the finite element method was used to analyse the stability of the Shirin earthen dam under various conditions. The necessary laboratory tests for soils used in the construction of the dam were carried out in the laboratories of the College of the Engineering /University of Tikrit, and these data were employed in the GEO-STUDIO program to analyse the seepage and stability of the dam. The seepage was analysed at three levels of the water lake reservoir including the highest, middle and lowest water levels. In addition, factors such as the permeability of the shell layer, the presence and thickness of the dam’s core layer, the placement of filters at the back of the dam and the exit gradient have been considered. The results have shown that by increasing the permeability of the shell layer, the exit gradient is decreased while the seepage through the dam body is increased. The presence of the dam’s core layer has a significant effect on reducing the amount of seepage through the dam’s body as the amount of seepage is reduced by (99%). Moreover, it was found that the minimum safety factor is 1.95 and it occurs after (4 days) of the rapid emptying of the reservoir, and this indicates that the upstream slope of the dams is safe during water emptying.