Postprint version. Published in Journal of Structural Engineering, Volume 125, Issue 7, July 1, 1999, pages 766-775.
NOTE: At the time of publication, the author Allen Estes was affiliated with the United States Army Corps of Engineering - Fort Leonard Wood, MO. Currently, August 2008, he is Head and Professor of Architectural Engineering at California Polytechnic State University - San Luis Obispo.
The definitive version is available at http://dx.doi.org/10.1061/(ASCE)0733-9445(1999)125:7(766).
As reliability based methods gain increased acceptance, there is greater opportunity to use scarce resources more efficiently while maintaining a prescribed level of reliability of a structure throughout its service life. The goal is to provide management decisions that will balance lifetime system reliability and expected life-cycle cost in an optimal manner. This study proposes a system reliability approach for optimizing the lifetime repair strategy for highway bridges. The approach is demonstrated using an existing Colorado State highway bridge. The bridge is modeled as a series-parallel combination of failure modes, and the reliability of the overall bridge system is computed using time-dependent deterioration models and live load models. Based on an established repair criterion, available repair options, repair costs, and updating, the optimum lifetime repair strategy is developed. The sensitivity of the optimum strategy to changes in various problem parameters including the prescribed service life, system failure criterion, and net discount rate is studied. Finally, the conclusions reveal that the proposed approach demonstrates real potential for practical applications, needs frequent updates through inspection, and requires considerable research effort to develop accurate input data.