Seismic safety enhancement of long span bridges with base isolation and structural control technologies

Abstract

Due to severe damage of bridges caused by the Hyogo-ken Nanbu Earthquake in 1995, very high seismic force is adopted in the seismic bridge design specification revised in 1996. Compared to the inelastic design methods, base isolation design and structural control design which reduce structural response with innovative devices have strong merit in vibration theory and in construction cost. In this paper, the recent development of the devices and their application to long span bridges are reviewed, and in addition the new negative stiffness damper under development is introduced.