The Effect of Steel Reinforcement on Seismic Damage to Concrete Gravity Dams Based on Distributed-Steel Model

Abstract

Tensile cracking at the position where geometry changes is a typical failure mode of gravity dams under strong earthquakes. Steel reinforcement has been proposed to reduce the degree of dam cracking. In this paper, a nonlinear model is presented to consider the interaction effect between the steel reinforcement and the dam concrete in a combined concrete damage model and distributed-steel model. In the model, a composite constitutive model of a steel reinforcement-concrete element is proposed. The approach can model the process of gradual degradation of the concrete loading capacity and load transfer to the steel reinforcement by establishing the concrete and steel models separately. Taking a typical gravity dam with positions where geometry changes upstream and downstream as a case study, the influence of steel reinforcement on seismic damage of the gravity dam is investigated. The analytical results show that the steel reinforcement strengthening prevents cracks thoroughly around the elevation of the downstream slope change. However, the cracking around the elevation of the upstream slope change extends to the downstream direction. This reflects the transfer of fracture energy release during the cracking process.