Investigation of Interaction between Rock Materials and Concrete Slabs in Concrete-Face Rock-Fill Dam (CFRD)

Abstract

In the CFRD dams, a concrete-face with a finite thickness is placed on the upstream side of the dam, which prevents water leakage from the reservoir. The construction of these dams with different heights and various specifications of materials have been welcomed a lot. Therefore, construction of CFRD is appropriate in pumped-storage reservoirs. However, due to the important role of concrete-face, the necessity of optimal studies in order to evaluate the behavior of this type of dams is obvious. In this research, the lower reservoir of Siah Bishe was studied by finite element method in order to investigate the interaction between rock-fill materials and simulated concrete-face and by an appropriate behavioral model in a three- dimensional mode that can simulate the behavior of materials in the body of the dam well. In this research, Plaxis software was used for modeling and static analysis was performed to determine deformations and stresses made in the dam and concrete slab. The elastoplastic behavioral model of Mohr-Coulomb was used to model the behavior of the materials and the technical specifications of the materials used in the body of the dam and concrete-face slab have been applied. The maximum value of settlement calculated by the software from the beginning of the constriction to filling the reservoir under the effect of gravity is 670 millimeter and the maximum settlement after phase 3 in the mode of the full reservoir in long term is 32 millimeter and the maximum horizontal displacement is 52 millimeter. Finally, the results of the settlements were compared to results of the instrumentation. The results indicate the approximation of results of the numerical modeling with results obtained from instrumentation.