Failure analysis and repair assessment of a steel box girder bridge

Abstract

The paper focuses on the failure of a motorway steel box girder bridge. After almost entire bridge had been completed (excluding deck equipment), there was a few month break in its construction. During this break, in two support sections of the steel box girder, an unusual failure occurred comprising the significant deformation (buckling) and local cracking of the steel webs. In the paper, the analysis of failure causes and the assessment of how these failures impacted the stress distribution in box girders have been presented. After construction of the bridge had been resumed, the failures were repaired. The steel superstructure after repair was also subjected to detailed analysis regarding change of stress distribution in repaired girder elements. All analysis were carried out using advanced numerical FEM models, allowing to consider sequences of particular loads (including those not typical for bridges) and repair works. Conclusions drawn from these analysis concern both the proper shaping of the steel bridge structure as well as the methodology of assessing impact of this type of failure on stress distribution in the structure and effectiveness of the applied repair method.