Seismic Damage Behavior of Gravity Dams under the Effect of Concrete Inhomogeneity

Abstract

ABSTRACT Dam concrete exhibits inhomogeneity due to its inherent material characteristic, construction-induced cracks/defects, and aging deterioration. The inhomogeneity may affect earthquake performance and seismic safety of concrete dams. In this work, a gravity dam-reservoir-foundation model, involving radiation damping, compressibility of reservoir water, and damage/cracking of concrete, is presented to investigate the influence of concrete inhomogeneity on seismic behavior of dams. The Weibull probabilistic distribution assumption is employed in the model to describe the heterogeneity of the dam concrete. A series of numerical analyses of the Koyna gravity dam, which is assigned with different heterogeneity indexes, is performed. The result demonstrates that the heterogeneity of concrete has significant influence on the seismic damage behavior of concrete gravity dams. A more heterogeneous material generally results in a larger dynamic displacement, a more severe damage pattern, and a greater damage level of the dam, indicating that an increase in homogeneity of concrete would be of benefit to seismic capability of concrete gravity dams.