NONLINEAR ANALYSIS OF CONCRETE GRAVITY DAMS

Abstract

In this dissertation various nonlinear models of studied.A mass concrete applicable for static and dynamic analysis.has beex~ mathematical model is proposed for the mechanical properties, constitutive relation and strength of mess concrete subject to dynamic reversible stresses and strains that may occur in gravity dams subjected to earthquake ground motion. The proper- ties of mass concrete subjected to two dimensional state of stress is described through the model. The proposed model is based on the experimental results available in the literature. Appropriate assumptions are made in the model where. experimental data were lacking.lb r example, the stress—strain curves in unloading and reloading were hypothesized in terms of the normalized stress—strain .curve, as no data were available for complete stress and strain reversals. Degradation of stiffness and strength under repeated cyclic loading is not included in the model. Two numerical examples of dam — foundation interaction has carried out. Both linear and nonlinear behaviours are` studied. Mohr — Coulomb yield criteria has been used to represent the yield surface. Newmark's implicit predictor—corrector time integration scheme is used for analysis. A sine sweep type of excitation representing an earthquake has been used for base excitation. Linear and nonlinear response of dam and zones of plasticity have been studied.