Effetcs of Near-Fault and Far-Fault Ground Motions on Cable-Stayed Bridges

Abstract

In this paper, the response of a long span cable-stayed bridge is investigated under the effect of near-fault and far-fault ground motions. Because cable-stayed bridges has been started to be used for center spans reaching to 1000 m it has become important to investigate the cable-stayed bridges under the effect of near-fault ground motions. Therefore, in this study a cable-stayed bridge is considered to determine the effects of near-fault and far-fault ground motions on the seismic responses of these types of bridges. Tatara Bridge constructed in Japan is chosen as a cable-stayed bridge model. Total length of the Tatara Bridge is 1480 m having a main span of 890 m. As near-fault and far-fault ground motions, 1995 Kobe, 1999 Chi-Chi, 1999 Kocaeli and 1999 Duzce strong ground motion records are used. Classifying near-fault ground motions as pulse type and none pulse type ground motions, the effect of near-fault ground motions on cable-stayed bridges has been investigated considerably. Bridge responses obtained from the near-fault and far-fault ground motion cases are compared with each other to emphasize the importance of earthquake ground motions on bridge responses. The results have underlined the remarkable effect of the pulse type near-fault ground motions on the dynamic responses of cable-stayed bridges.