FEASIBILITY OF CONCRETE GRAVITY DAMS IN HIMALAYAS

Abstract

Concrete gravity dam is a solid concrete structure with its cross-section approximately triangular in shape, so proportioned that the external forces exerted on it are resisted by its own weight. The pattern of' stress distribution and dclormations in the dam Foundation system are of great concern for safety and economy case of a high concrete gravity dam founded on a weak rock. Any variation in foundation properties and dani height would largely affect the safe design of the foundation and dam. In this dissertation, the stresses and deformations have been studied by using 2-D Finite Element Method. Four cases have been studied in this dissertation work. Dams of height 125m (Case 1), 150m (Case 2), 175m (Case 3) and 200m (Case 4) have been considered. Each case has been analyzed with varying modulus of foundation i.e. 0.2, 0.4, 0.6, 1.0 and 2.0 times of concrete. For each case constant foundation extent of 1.5H (H = Height of darn) on both laterals the depth is considered. Rigid boundary condition at bottom and both lateral vertical sides of foundation has been considered in the analysis of all cases. Each case has been analyzed for the loading combination of self weight of the dam + reservoir water pressure + normal uplift pressure + earthquake force. Results of these case studies, in respect of distribution of stresses and deformations, have been analyzed and discussed in this dissertation....