Lining Thickness Optimisation for Composite SCL Tunnels

Abstract: This paper presents a composite SCL tunnel secondary lining thickness optimisation study. It first introduces the numerical model that simulates the behaviour of an SCL tunnel and the modelling strategy for the composite action between the primary and secondary linings. It then reports the influence of variation in the secondary lining thickness on the sufficiency of lining and interface capacity to maintain the integrity of the composite SCL tunnel. The key findings are reported and the implications for the practical design of SCL tunnels are discussed.