Expansion Joints for Seismic Isolated Bridges

摘要

Much emphasis has been given to the analysis and design of bearings in seismically isolated bridges however, not much research or effort has been made to the design of joints that can accommodate seismic movements. Until recently, the prevailing design philosophy was to accept damage at joints during a seismic event, which could be repaired or replaced at a later date. In shifting the seismic performance criteria from safety to functional approach, expansion joints have to tolerate not only large longitudinal and transversal movements but also vertical settlements. At the same time, they have to maintain full access to regular traffic almost immediately following the maximum considered earthquake. This paper presents recent designs and applications of seismic expansion joints in California bridges.