Optimal Maintenance Period Determination to Minimize Life Cycle Cost of Railway Bridges

The bridges as important links are connected all road networks and railways That a huge investment is needed to build them. In addition, bridges are considered as important points of vital arteries. If the bridges due to old age, exhaustion, overload, weather conditions, natural disasters and etc. destroyed, repair works are much more costly than the budget needed for the maintenance of them. Available budgets for reconstruction and maintenance, usually is not enough to maintain a constant state throughout the lifetime of the bridges. Due to the large number of bridges and high maintenance costs, it is not possible to repair and pay for maintenance of bridges simultaneously. In this study, the life cycle cost is calculated based on maintenance period of railway using multi-objective particle swarm optimization algorithm. Sensitivity analysis, furthermore, is done on deterioration rate and reduction of deterioration rate and effect of these parameters on system performance are analyzed.