Author(s)

H. Otsuka, K. Yamahira, H. Kusuda

Abstract

Study on the seismic retrofit of a steel cable-stayed bridge H. Otsuka', K. Yamahira' & H. Kusuda' * Department of Civil Engineering, Kyushu University, Japan *Sumitomo Heavy Industries Ltd., Japan Abstract This paper shows the effectiveness of a seismic isolator for the retrofit of a steel cable-stayed bridge that has girder movement exceeding the yield strength and bearing supports on which the reaction forces exceed the designed axial forces. It is clarified by numerical calculations which show that suitable locations and vertical stiffness of isolators can reduce the response of internal forces and increase structural safety in the event of a large earthquake. 1 Introduction After the 1995 Great Hanshin-Awaji Earthquake, seismic loads were increased drastically in Japan; for example from 0.7 to 2.0 in maximum acceleration response spectra on stiff ground for highway bridges. Also, highway bridges such as cable-stay bridges, whose dynamic behaviour is complicated during

Keywords