Variations in seismic retrofit design of cable-stayed bridges of different sizes

Abstract

There are three cable-stayed bridges in Nishi-Seto Expressway, the westernmost route of Honshu- Shikoku Expressway; Shin-Onomichi Bridge (maximum span of 215 m), Ikuchi Bridge (center span of 490 m), and Tatara Bridge (center span of 890 m). The results of seismic analyses of the bridges revealed the considerable sway-mode vibrations in longitudinal direction, and seismic devices such as viscous dampers and stoppers were found to be necessary to mitigate the above vibrations. In this paper, the vibration characteristics of the cable-stayed bridges of different sizes and the difference in the seismic retrofit design for the bridges are presented.