Seepage Analysis and Control of the Sahand Rockfill Dam Drainage using Instrumental Data

The finite element method is an effective numerical technique for the accurate analysis of seepage, enabling the determination of outlet flow and pore water pressures at any point in the dam body and foundation. In this study, the seepage behavior of the Sahand Dam was analyzed using the finite element method and PLAXIS software, and the results were validated with instrumental data. After validation, permeability coefficients were employed to investigate factors affecting seepage at the reservoir's normal water level, such as the cutoff wall, upstream concrete cover, clay blanket, and foundation depth. The results show that the combined implementation of a clay blanket and an upstream concrete cover causes a significant reduction in dam discharge. Finally, by evaluating the effective parameters influencing dam seepage, an optimized model was developed. In this optimized model, the discharge was reduced to one-third of the corresponding value in the initial dam model.