Bridge load testing and damage evaluation using model updating method

Abstract

In this paper, the performance of a precast-prestressed box-beam bridge that had been in service for more than 50 years was investigated using a series of static and dynamic load tests. The bridge was instrumented to record individual panel deflections under live loads. A detailed finite element (FE) model was developed for better understanding the bridge behavior with suspected damage at deck panel joints. A comparison between the results of the FE model and actual bridge response confirmed damage at the deck longitudinal joints, also inferred by the observation of reflective cracking on the deck surface. Using the FE analysis and load testing results, a new damage detection method for structural health monitoring of these bridges with precast deck panels was introduced. This method can effectively identify locations and significance of potential deck joint damage based on the measured changes in bridge response and model updating. The results showed that such joint damage affects the bridge integrity, alters the live load distribution, and can potentially reduce the bridge load-carrying capacity.