Fatigue and Fracture Performance of Heat-Straightened Steel Bridge Girders

摘要

The purpose of this research was to establish limits on the heat-straightening process of damaged steel bridge girders and to provide guidelines for the repair based on the fatigue and fracture performance. Multiple steel girders were dynamically damaged using a large scale drop weight machine, repaired using the heat-straightening repair process and fatigue tested. Up to three damage and repair cycles were made on a specimen at the same location. It is recommended that the number of repairs be limited to two when damaged caused by repeated impacts falls within the limits of the repair of the first impact. Evaluation, repair and inspection techniques were also developed during the laboratory research to assist the owner, engineer, and heat-straightening contractor throughout the repair process. Impact area treatment, NDT inspection recommendations, restraining force evaluation, stiffener repair, and residual damage limits have been included in the findings presented in this report.