عنوان مقاله [English]
The core of earth dams plays an important role not only in dam sealing but also in the possibility of hydraulic failure. Therefore, choosing the dimensions and type of materials for the core of earth dams is very important. In this research, the aim is to investigate the phenomenon of hydraulic fracturing and the effect of the dimensions and shape of the clay core on the reliability coefficient of hydraulic fracturing. For this purpose, first, using finite element model , the phenomenon of hydraulic fracturing in two sections of the middle of the core and the upstream side of the core for two types of CL and CH materials has been investigated. Analyzes have been done in the stages of construction completion, initial dewatering and steady state seepage, and the stages of dam construction have also been considered in the modeling. The results show that CL soil is the critical soil and CH soil is the selected soil to be used in the core of the dam. Also, the possibility of hydraulic fracture in thicker cores and the bottom of the core was also investigated. The results showed that the criteria of Fukushima and Ghanbari have the most optimistic data and the most conservative data, respectively. According to the criteria used in this research, CH soil is safe from hydraulic failure and the possibility of hydraulic failure for critical soil (CL) in the downstream of the dam core was found to be probable.