Investigation of Structural Behavior of Tapered Ring and Parallel Ring Linings in Tunnels

This paper presents an analysis of the structural behavior of both tapered ring and parallel ring linings in a tunnel design project using a shell-spring approach. This is done to examine whether the tapered ring lining can be approximated as a parallel ring lining. The results show that, under the same load conditions, the maximum positive bending moment and axial force of the tapered ring model varies little compared with the parallel ring model. However, the maximum negative bending moment and maximum deformation in these two models vary significantly. Under conditions of different joint orientations, the maximum negative bending moment and deformation differ by as much as 19%, regardless of which lining model is used. Thus, the simplification of a tapered ring lining as a parallel ring lining for use in tunnel design is not sensible.