ABSTRACT
Recently, Life-Cycle Cost (LCC) analysis has been paid attention as a possible and promising concept to achieve a rational maintenance program. In this study, an attempt is made to develop an LCC analysis of bridge structures considering seismic risk. A stochastic model of structural response is proposed, which accounts for the variation due to the uncertain characteristics of earthquake. Then, the probability of failure due to the earthquake excitations is calculated based on the reliability theory. Using the failure probability, LCC can be calculated for the bridge structure with earthquake excitations. Another attempt is made to develop an optimal seismic design system of road network by using Multi-Objective Genetic Algorithm (MOGA) and introducing reliability index and LCC. The reliability index and LCC can not be optimized simultaneously, because both have a trade-off relation. In this study, multi-objective optimization is introduced to obtain several Pareto-solutions. Furthermore, LCC is calculated by introducing the user cost due to the occurrence of earthquake. Several numerical examples are presented to demonstrate the effectiveness of the proposed method.
