Numerical Investigation of dip angle direction of foundation Joint on nonlinear dynamic response of concrete gravity dams

The stability of a gravity dam on a jointed rock foundation might be endangered by weak joints that may be present in the fracture network of the bed rock. A review of the literature shows that there are few studies of the effect of a weak joint in the foundation rock on the stability of dams. This research uses the finite difference numerical modelling software ABAQUS to model a gravity dam, the foundation rock, and the influence of a weak joint (using interfaces), that exist in the bottom of dam with different direction, on the stability of the dam. To do this, a conceptual model has been developed and one representative joint of a discrete fracture network with seven different dip angle was examined. Thses different varying dip angles were studied in order to investigate the critical configuration that has the most significant effect on the dam’s stability.As a case study, Pine Flate dam, is modeled with the ABAQUS software as a two-dimensional and Nonlinear dynamic analysis is done by implicit method with applying vertical and horizontal components of the El-Centro earthquake. The obtained results show that existness of joint in the foundation significantly affected the dynamic responcse of dam.