Implementation Project: Strengthening of a Bridge near Hondo, Texas using Post-Installed Shear Connectors

This project was an implementation of research conducted under Texas Department of Transportation (TxDOT) Research Project 0-4124 on the use of post-installed shear connectors to develop composite action in existing non-composite steel bridge girder systems. In this implementation study, an existing non-composite bridge in the San Antonio District was retrofitted with three types of post-installed shear connectors to increase the load-carrying capacity of the bridge girders. The bridge is located near the town of Hondo, Texas, and is referred to herein as the Hondo Bridge. A detailed design for strengthening the Hondo Bridge was undertaken in this study. Potential design and construction difficulties were identified and solutions to these difficulties were suggested. The bridge consists of three identical simple spans and each span was retrofitted with a different type of post-installed shear connector. A load rating was conducted for the Hondo Bridge prior to retrofit, showing an HS10.6 inventory level rating and an HS17.6 operating level rating. With the addition of the post-installed shear connectors, the load rating for the bridge increased to HS17.4 inventory level and HS29.1 operating level. Thus, both the inventory level and operating level load ratings increased 65% as a result of the installation of post-installed shear connectors. Field live load tests were conducted to verify the development of composite action in the bridge girders after installation of the post-installed shear connectors. Installation of the shear connectors in the Hondo bridge proved more difficult than anticipated. Construction difficulties and possible solutions are discussed in the report.