STRESS ANALYSIS OF-CONCRETE GRAVITY DAMS

Abstract

Several methods are available for stress analysis of concrete gravity dams. In this dissertation a comparative study of a few of these methods$ namely, (a) Davis method Si) and (b) USBR method (2) , has been made. The stresses as obtained bthese methods are also compared with theory of elasticity solution of Zienkiewicz for a triangular dam section and with the finite element stresses for Koyna damU 5) under static forces. Static and dynamic forces have been considered in this study. The dynamic forces are treated as "equivalent static forces". Three different variations of the seismic coefficient along the height of the dam have been studied with a view to...investigate the most appropriate variation to be considered in stress analysis of concrete gravity dams. Dams of different heights and different upstream and down-stream s1oD s have been analysed. The study herein indicates that the stress distributions as obtained by the Davis and the USBR methods differ considerably from both the theory of elasticity(B) and the finite element analysis (15) for Th the regions at and near the base of the dam where the width of the dam is large, For hydrostatic pressure, the Davis and the USSR methods give different stresses' as compared to those obtained by the finite element analysis (I5). This difference is more significant at and near the base of the dam. Under static forces the theory of elasticity and the finite element method indicate a definite tension at the U/s face on the base: This fact is not revealed by the Davis and the USBR methods. The Davis and the USSR methods differ signifi-cantly from each other only at and near the base of the dam.