FDM analysis of earth dams – end of construction and water seepage (case study: Ivshan Iran dam)

In this research, the Ivshan earth dam was modeled with the finite difference method (FDM) for staged construction and water seepage. A maximum settlement was 100 cm in the numerical model when construction was complete, and it occurred in the middle of the dam's height. Also, the FDM results showed consistency with field observations of the deformation instrument (inclinometer). After the reservoir's initial filling, the pore water pressure ratio changes were investigated for the dam's central axis. The results of the numerical model show relative stability in terms of pore water pressure ratio. The arching ratio is also obtained in the dam's central axis for both construction and initial filling. The lowest values of the arching ratio in the central axis of the core at the end of construction and initial filling are 0.81 and 0.80, respectively, which occurred at the height of about 41 meters and about two thirds of the height of the dam embankment. Finally, the Factor of Safety of the dam at the end of construction and initial dewatering was investigated, and the results showed the stability of the earth dam.