Study on maintenance planning for tunnels by risk management system

This paper presents a planning method of maintenance strategy for railway tunnels in Japan. The method adopted in the case study aims to find an optimal maintenance strategy to minimize the expected "Total Cost", which includes costs and risks. In the formulation, the probabilistic state vector consisting of deterioration ranks defines the state of structures. The proposed new planning method is able to indicate the optimal repair timing considering each characteristic of lines. The new approach of tunnel management will provide rational and reliable maintenance for aged railway tunnels.