Effects of Large Cumulative Travel on the Behavior of Lead-Rubber Seismic Isolation Bearings

Lead-rubber bearings are seismic isolators that have been used extensively to protect buildings, bridges, and mission-critical infrastructure from the damaging effects of earthquake shaking. In bridges, lead-rubber bearings are subjected to continuous movement due to service (traffic) and temperature effects. This paper presents data on the effects of cumulative travel on the mechanical properties of lead-rubber bearings based on an experimental investigation of both medium- and small-sized bearings. A theoretical interpretation of the test results is presented.