A Study on the Seismic Isolation Systems of Bridges with Lead Rubber Bearings

摘要

This study consists of the development and presentation of example of seismic isolation system analysis and design for a continuous, 3-span, cast-in-place concrete box girder bridge. It is expected that example is developed for all Lead-Rubber Bearing (LRB) seismic isolation system on piers and abutments which placed in between super-structure and sub-structure. Design forces, displacements, and drifts are given distinctive consideration in accordance with Caltrans Seismic Design Criteria (2004). Most of all, total displacement (D_(TM) = 457 mm) on design for all LRBs case is reduced comparing with combined lead-rubber and elastomeric bearing system (D_(TM) = 533 mm). Therefore, this represents substantial reduction in cost because of reduction of expansion joint. This presents a summary of analysis and design of seismic isolation system by energy mitigation with LRB on bridges.