Effect of near-fault ground motion with pulse signal on dynamic response of dam-reservoir-foundation systems

Abstract

This paper aimed to determine the effects of a pulse signal of near-fault ground motion on the dynamic response of gravity dams, including dam-reservoir-foundation interaction, using different reservoir modelling approaches such as Westergaard, Lagrange, and Euler. As a case study, a Sarıyar concrete gravity dam located on the Sakarya River, 120 km northeast of Ankara, was considered for investigating the near-fault ground-motion pulse effects on dam responses. First, the main principles and basic formulations of these approaches were presented. Then, finite element models of the dam were realized considering dam-reservoir-foundation interaction using ANSYS software. To determine the structural response of the dam under pulse effects of the near-fault ground motion, linear transient analyses were performed using the 1999 Taiwan Chi-Chi and 1979 Imperial Valley ground motions, which display apparent velocity pulses as representative of the near-fault earthquakes. Subsequently, the dynamic characteristics were compared to demonstrate the models of the fluid domain effects and pulse signal effects.