Practical life-cycle-cost effective optimum design of steel bridges

This paper presents a practical Life-Cycle Cost (LCC) formulation and procedure for the LCC-effective optimum design of steel bridges. A general LCC model for optimum design of steel bridge consists of those of initial cost and direct/indirect rehabilitation costs of a steel bridge including repair/replacement costs, loss of contents or fatality and injury losses, road user costs, and indirect socio-economic losses. Thus, this paper focuses on the presentation of a general formulation of LCC models and LCC effective design system models for steel bridges suitable for practical implementation. And then, in order to demonstrate the LCC-effectiveness for design of steel bridges, the applications of LCC-effective optimum design to actual steel bridges as illustrative examples are performed with discussion. From the results of the numerical investigation, it may be stated that the optimum design of steel bridges based on the LCC approach proposed in this paper will lead to more rational, economical and safer design compared with initial cost optimum design as well as conventional design.