ADVANCES IN CIVIL ENGINEERING, İstanbul, Turkey, 21 - 23 September 2016, vol.1, no.1, pp.1-8
Near-fault ground motions may sometimes contain a strong pulse at the beginning of the velocity time history. These ground motions containing large velocity pulses and known as pulse-like ground motions caused by directivity effects are a special class of ground motions. They can have a significant impact on engineering structures. In this study, it is aimed to determine effects of pulse signal of near-fault ground motion on dynamic response of gravity dams including dam-reservoir-foundation interaction to different reservoir modelling approaches such as Westergaard, Lagrange and Euler. As a case study, Sarıyar concrete gravity dam located on the Sakarya River, which is 120km to the northeast of Ankara, is selected to investigate the near-fault ground motion pulse effects on dam responses. Firstly, the main principals and basic formulation of all approaches are given. After, the finite element models of the dam are constituted 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, the linear transient analyses are performed using 1999 Taiwan Chi-Chi and 1999 Taiwan Chi-Chi ground motions that displayed a ground motion with apparent velocity pulse were selected to represent the near-fault earthquake with pulse signal. In the analyses, element matrices are computed using the Gauss numerical integration technique. The Newmark method is used in the solution of the equation of motions. Rayleigh damping is considered. At the end of the analyses, dynamic characteristics, maximum displacements, maximum stresses are attained and compared with each other to demonstrate water modelling effects and pulse signal effects.