APPROXIMATE METHODS FOR DYNAMIC ANALYSIS OF CONCRETE AND MASONRY GRAVITY DAMS

Abstract

Several simplified methods have so far been developed . for aseismic design of concrete end masonry Frravity dams at the preliminary stages. The method suggested by G. Fenves and 4.K, Choprs has been upgraded to a great extent with the inclusion of the effects of. dam-reservoir interaction, dam-foundation rock interaction, reservoir bottom absorption and compressibi-lity of wster.But r~one of 'these methods considers the effect of nxiRl deformation due to vertical ground motion. The purpose of this thesis is to study the dynamic response of concrete and masonry gravity dams subjected to. vertical ground motion, so as to suggest some modifications in the existing.coda,l provisions for inclusion of axial deformation•effects. For this, bending shear analysis using beam model has been adopted to analyse eight dams of height ranging from 64 M to 225 M. :^=n effort has been made to establish period and .axial 'force coefficients for dams of different heights. In this thesis, the influence of foundation flexibility, inertia and size of foundation on dynamic response has also been studied. Seismic analysis of dams by simplified method of Fenves and Chopra considering foundation flexibility is another aspect studied in this thesis.