Lifetime reliability profiles for steel girder bridges

The objective of this study is to develop rational criteria for evaluation of existing steel bridges. The proposed approach is based on reliability analysis of components and systems. The procedure includes the selection of representative bridges, gathering of site-specific data on load and resistance models, reliability analysis, and processing of results. An important consideration is given to deteriorated structures. The procedure for the development of rational evaluation criteria for steel bridges was formulated using the available statistical data on loads and resistance, strength deterioration models, and reliability analysis methods. The major steps included selection of representative structures, formulation of limit state functions, selection of load and resistance models, selection of the reliability analysis method, reliability analysis of selected bridges, and the development of time-dependent reliability-profiles including deterioration due to corrosion. Fatigue limit state is also considered as a part of this study. The major parameters which determine structural performance include load components, strength of material, dimensions, and degree of deterioration (corrosion).