*** 9522166 Frangopol The main objective of this research is to develop a framework for considering system reliability in evaluation and design of steel and concrete highway bridges. The study consists of several major tasks. After a review of both the current component-oriented methodology and the applications of system reliability concepts in bridge evaluation and design, an objective and practical system-oriented reliability-based methodology will be proposed. In this regard, both serviceability and ultimate limit states will be considered based on the Load and Resistance Factor Design method. Using the incremental loading fault-tree strategy, system factor modifiers will be introduced in both bridge evaluation and design to account for the presence and interaction of individual components in the bridge system. In this manner, the full potential of system reliability concepts to the advancement of bridge evaluation and design processes will be realized. A data base consisting of at least forty-three highway bridges located in the U.S. in thirteen different states will be used to demonstrate and validate the applicability of the proposed methodology. The end result will have a significant impact on improving the management of the reliability of our highway bridge infrastructure. In fact, the proposed bridge system reliability methodology will greatly assist engineers in making more rational decisions with respect to both safety and economy in evaluating and designing highway bridges.***
