Operational Structural Performances of Bridge Types by Deterioration Trends

Abstract

This paper demonstrates the analysis of the deterioration trends of bridges to evaluate the operational structural performances of the various kinds of bridge construction materials and/or structural designs. The goal of this study is to improve the performance of structural materials used to construct bridges, based on rigorous population-based analysis of the performance of those materials in service. The analysis uses the raw database of the entire National Bridge Inventory in the United States and derives material deterioration aspects at the serviceability limit states. The study develops measures of deterioration to consider the trends in the accumulation of structural deficiency versus service life cycle by material. The approach defines the criteria of rate and pattern performances to analyze the comparative deterioration trends. A multiple-criteria diagnostic approach determines the overall equivalent structural performances integrating the rate and pattern performances with the measures of condition, durability, and longevity. The national network-level operational experience by categorical deterioration trends produces the most comprehensive comparative basis of structural performance of bridge materials. Overall for all bridges, the average increase of structural deficiency is 0.51%/year, adding to the already existing 12.35% and consisting of an average annual increase of structurally deficient bridges by 4.10%. The accumulation of structurally deficient bridges begins only after 10 years for most materials. The rate and pattern performances of almost all of the materials are quite poor. Thus, the equivalent performances integrating the deterioration trends are lower. The results provide a more objective indication and comparison of structural performances under the actual circumstances and help predict future performance. The approach supports the development of improvements necessary to increase the relative performances of distinct bridge materials for more sustainable service.