Risk-cost optimised maintenance strategy for tunnel structures

As an essential infrastructure tunnels play an important role in transport network. The functionality of this infrastructure depends on its structural and durability performance. In the climate of an increasing scarcity of resources, infrastructure maintenance is becoming increasingly important. This paper aims to develop a maintenance strategy for tunnels, which determines when, where and what to maintain, to ensure the safe and serviceable operation of tunnel structure with the intention to minimise the total risk. Application of the proposal is presented in a numerical example of a practical case study. It was found that an optimum solution, which can predict when, where and what to maintain for tunnel structure to ensure its safe and serviceable operation during its lifespan, exists. The paper concludes that the proposed framework can equip tunnel operators and asset managers with a tool in developing a risk cost optimised maintenance strategy for tunnels under their management.