ABSTRACT
A proposed innovative tunnel lining system has been developed with the aim of reducing overall costs, including construction, manufacturing, and freight of segments. To achieve this objective, the proposed liner is an in-situ steel framed concrete liner consisting of a simple steel form containing filled-in concrete. The liners are connected with liner joints. The present study verified the structural characteristics and design method of the proposed liner. Studies confirmed the following: (1) The experimental results of the bending tests of the main member showed that the proposed composite structure can be designed on the basis of an RC system, wherein the steel form is treated as equivalent to reinforcing bars. (2) The experimental results of the bending tests of the joint member showed that the liner joint can be designed on the basis of an RC system and beam-spring model theory.
