Rehabilitation and Retrofitting of a Multispan Simply-Supported Adjacent Box Girder Bridge into a Jointless and Continuous Structure

Abstract

The widely-utilized multispan simply-supported adjacent (side-by-side) box girder bridges often suffer from problems of deterioration attributable to transverse cracking in link slabs between spans, malfunctioning expansion joints, and longitudinal cracks between adjacent girders. Such problems can degrade the functionality, durability or even safety of the bridge over time, depending on the environmental exposure conditions. This paper discusses an approach taken to rehabilitate the Shili Bridge by eliminating expansion joints and retrofitting the structure from simply-supported box girders into a continuous bridge. Condition assessments were performed before retrofitting. In addition, several design options and construction procedures were considered and analyzed. Static and dynamic load tests were carried out after the completion of rehabilitation. The lessons learned in this project are presented and discussed. This practical and novel methodology is a step forward toward improving safety, sustainability, reliability, and quality of such existing bridges in China and elsewhere.