Traditional condition rating procedures concentrate on member condition and give no consider-ation to system behavior. In this paper a methodology is proposed to modify the correction factor applied dur-ing the assignment of bridge condition rating to account for bridge system behavior. Robustness and redun-dancy concepts that have been used in the past for structural design of new bridges and for assessment of existing bridges are in this work extended to condition rating, which represents the first step in existing bridge evaluation processes. In this paper, corrosion of steel girders is considered as the main cause of material deg-radation. The inclusion of a system-based corrective factor serves to take into consideration the system behav-ior of steel multi-girder bridges and their ability to redistribute the load after initiation of corrosion or the fail-ure of one member. By including the proposed correction factors, bridge inspectors will decrease condition ratings of less robust bridges that exhibit low levels of system capacity in their damaged state and increase the rating of robust bridges. Different system-based correction factors are assigned based on structural types and configurations, as well as the type, location, and extent of damage. The system-based correction factors pro-posed in this research are calibrated based on reliability index criteria and take into account the relative im-portance of the member under inspection to the overall bridge system integrity and safety.

Peer Reviewed