Evaluation of the Material Permeability Ratio of Earthen Dam with Clay Core Using By 3D Seepage Modelling (Case Study: Sattarkhan Dam)

One of the most important issues in the design of earth dams is the analysis of dam body and foundation seepages. Seepage problems may be caused by the characteristics of the foundation, support, floor and walls of the reservoir or dam body materials. Therefore, one of the determining parameter in the stability evaluations of earth dams is seepage analysis. In this study, seepage analysis of Sattarkhan dam is located in East Azarbaijan province, has been done by using the finite difference method, Flac3D software. The behavior of the seepage analysis model has been investigated and compared in two and three-dimensional case. The results of the analysis have been compared and validated with the pore water pressure measured by piezometers installed in the core and have been in good agreement. The main variable in the seepage analysis of dam is the permeability coefficient of the material. The role of this coefficient in the results of the seepage analysis of the dam body has been investigated by sensitivity analysis.In general, it can be said that in the mentioned dam, the water flow vector parallel to the dam axis is not decisive, and the pore water pressure production process complies the two-dimensional model approach. Also, the results show that the permeability ratio of the shell related to the core is effective in its seepage behavior, and in the design of the earth dam body s, it will be necessary to check this ratio according to the property of the borrow mines located in the dam construction area.