Seismic response of continuous bridge with isolation bearings

Abstract

The response of a bridge depends greatly on the type of the bearings used. The performance of a particular type of bearing is affected by age, temperature, scragging, velocity, travel, contamination and level of ground movement. This paper examines the thermal and seismic response of a three-span continuous bridge with various types of isolation bearings, including the effect of possible variations in properties. A three-dimensional model of an existing bridge has been developed with non-linear modelling of the bearings. The response of the bridge has been studied for a set of five recorded acceleration–time histories and five scaled time histories to make them compatible to a site-specific design spectrum. The sensitivity of the bridge response to various bearing design parameters has been studied. The restoring effect available in different types of bearings with varying design parameters has been compared. The effect of source–site distance on the relative performance of various bearings has also been studied.