Comparison of load rating evaluation of PSC-I girder bridges using response correction factor and real-coded genetic algorithm model updating method

To evaluate the load carrying capacity of a bridge, it is necessary to set up an appropriate analytical model for the bridge. According to the current guideline or manual, the load rating is calculated with the response correction factor obtained from the difference between the response measured through the field load test and the response by the analytical model. According to the criteria for evaluating the load capacity, for conservative evaluation, it is suggested to use the response correction factor at the location where the axle weight of the test vehicle is directly applied, and to select the location with the largest response correction factor. The purpose of this study is to propose and examine a method for estimating the load rating of PSC-I girder bridges by updating the model that minimizes the difference between the measured and analyzed responses with a real-coded genetic algorithm (RCGA). In addition, the reliability of the method for estimating the load rating through the available response correction factor was investigated. The results were compared with those of the genetic algorithm (GA) model updating method. In the study, a pseudo-static load test method was proposed and applied as a field load test for PSC-I girder bridges, and its advantages were analyzed.