Study of Seepage Flow and Cutoff Wall Performance of Eyvashan Earth Dam Using Numerical Analysis

One of the most important issues in earth dams is the control of water leakage and the rate of leakage from the dam body and its foundation. Due to the site of the dams, in order to increase the creep length and reduce the leakage, there are several methods for sealing the reservoir of dams. Construction of the cutoff under the clay core of the dams is one of the most effective methods. In this research, the Eyvashan dam leakage analysis was performed with the aim of evaluating the performance of the cutoff wall model in the section and calculating the total discharge flow rate from the foundation and dam body. The maximum amount of leakage flow in the level pool of reservoir conditions is 26.37 liters per second, which was obtained using multivariate regression and the coefficient of determination of the values of R2 = 0.9929 and R2 = 9930 for Geostudio and Plaxis software, respectively. This indicates a good match between observed and predicted data and the proper performance of the dam in terms of seepage discharge. Also, the water pressure level at the downstream side of the cutoff wall has a sudden drop based on numerical modelling which indicates the correct performance of the cutoff wall.