TATSUO OHMACHI - Professor, Department of Built Environment, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, Yokohama, Japan
ABDOLRAHIM JALALI - Graduate Student, Ditto

Effects of polarization of input ground motion in the near-fault on linear response of an arch dam are studied. Two sets of ground motions recorded at dam site and near-fault,have been selected. Directional dependency of amplitude and frequency content of the ground motions are thoroughly analyzed. To show the effect of polarization of ground motion at near fault, we have conducted a linear analysis, by considering all important factors in earthquake response of arch dams (i.e., dam body, foundation rock, and reservoir). The variation of stresses at all elements on upstream and downstream face of the dam due to different angle of incident are studied. The dam stresses are found to show remarkable increase or decrease depending on the angle of incident of input ground motion with respect to dam axes.