Buckling behavior of steel girder in integral abutment bridges under thermal loadings in summer season during deck replacement

Integral abutment bridges (IABs) have been built and successfully served for several decades, especially in the U.S. and Europe, because of their many advantages, such as their structural efficiency, stability and low construction and maintenance costs. Recently, the deck slabs of IABs have reached the end of their service lives and bridge administrators have decided to replace the deck slabs to extend the bridge service life. Due to the restraints at both abutments, the steel girder IAB is subjected to high axial forces and the steel girders have laterally buckled during deck slab replacement. This study performed numerical simulations to identify the buckling modes that may occur during deck replacement and the results were compared to the recent accident which happened in Missouri, U.S. Key parameters such as the length of the girder, width and thickness of the flange and the imperfection level were selected and a parametric study was performed. Using the obtained critical buckling stress, an equation for predicting the critical buckling stress of the girder in IABs during deck removal was developed. The results provide a better and safer, long-lasting IAB design and maintenance regime.