The Research On Bridge Design Theory Based On The Life Cycle Cost (LCC)

With Regard to high cost of bridge maintenance currently, a modified bridge design theory which is based on the life cycle cost has attracted increasing attention gradually. The bridge design theory based on the life cycle cost refers to, in the beginning of bridge design, the innovative design approach to ensure an optimized bridge life cycle cost on the basis of a secure operation of bridge.In this thesis, we make an assessment and prediction of the performance of the structure with reference to the two theories of time-variably reliability and condition states and achieve favorable results, in the meanwhile, we established the relationship between condition states and maintenance cost, to optimize bridge life circle maintenance and set up objective optimization function and bridge maintenance safety provisions so as to meet the requirement of a reliable life circle structure and guarantee the least cost of maintenance for the bridge structure in its life circle. Then we can predict the most favorable life circle maintenance cost.Furthermore, this thesis also supply a model for calculating social cost and user's cost of bridge structure which will lay foundation for future work. Furthermore, the paper also gives the model to calculate the social cost and user cost, and make the base for the further research.In this thesis, we set our background in Lishui Bridge over Shigui Mountain in Changsde, Hunan province. Through life circle cost program, the cost perdition of bridge structure in its life circle and its maintenance optimization can be demonstrated vividly. Therefore, if the idea of life circle cost design is introduced in the beginning of bridge design and an analysis of maintenance program in bridge life circle can be made by optimization theory then the least maintenance cost in bridge life circle and the most profit can be guaranteed based on a safe operation of the bridge.