ABSTRACT
ABSTRACT: Based on life-cycle cost (LCC) analysis method, this paper presents conceptual framework of LCC-based bridge design method. Namely, taking bridge service level as a basis, the design method minimizes the net present value of life-cycle cost during bridge lifetime as optimal performance objective, and makes use of life-cycle cost analysis method to evaluate bridge design strategy subjected to structural performance constraints whether or not it is an optimum strategy. Life-cycle cost model can be determined by establishing traffic model and bridge lifetime performance prediction model that is associated with bridge serviceability under aggressive environmental attack. Therefore, the hybrid life cycle cost optimization model can be constructed based on the above models. An approach to investigate LCC-based bridge design is proposed in this paper, including systematic method study, parametric uncertainties analysis and risk evaluation. At the same time, structural failure modes and bridge time-variant reliability are researched, and the hybrid life-cycle cost optimization techniques are discussed in the paper. Optimal algorithm is employed as a search method for the optimal design strategy solution, and Monte Carlo simulation is taken as risk analysis approach to account for the uncertainties. The method that stresses on the interaction of lifetime performance prediction, reliability-based life-cycle cost and maintenance/repair interventions has many advantages, such as explicit concept and convenient realization. The related theories developed in this paper can provide conduction for bridge design, construction and lifetime maintenance or replacement actions.
