Bridge Fatigue Life Estimation from Field Data

This paper presents the application of field data to condition assessment and prediction of service life of highway bridges. The study examined fifteen bridges located in Illinois for damage evaluation purposes. The example bridges are all composed of steel girders with reinforced concrete deck slabs. Only the superstructure was investigated for potential fatigue damage to the critical structural details of the main steel girders. The current condition of each bridge was assessed based on fatigue damage induced in the critical components of the bridge and the bridge fatigue life. The critical components investigated are steel girders with welded cover plates. The field stress range data compiled for each bridge was used along with a probabilistic method to estimate fatigue life. The results were then used to investigate the significance of truck weight increase and traffic growth on fatigue life.