Numerical Analysis for Investigation of Hydraulic Fracturing Potential of the Rockfill Dam

Abstract

Embankment dams may collapse because of internal erosion that develops in the crack developed in the upstream-downstream direction by hydraulic fracturing. It is known in the literature that many dams collapsed due to hydraulic fracturing. The hydraulic fracturing mechanism is defined as the propagation of an existing crack on the upstream face of the clay core under hydrostatic stresses or the formation of a new crack in low-stress zones by hydrostatic stress. The variety of materials and materials' mechanical properties generally affect the hydraulic fracturing potential. This study examined the effect of the deformation parameters (Elasticity modulus and Poisson ratio) of the impermeable curtain-function clay core material on the hydraulic fracturing potential. Normal Stress and Mohr-Coulomb methods were used to determine the hydraulic fracturing potential. The principal stress values required for these two methods were determined for the maximum cross-section of the clay-core rockfill type Çınarcık Dam by the finite element method. While the hydraulic fracturing potential is negligibly affected by the change of deformation parameters in the Normal Stress method, this effect is clearly seen in the Mohr-Coulomb method.