MEASUREMENT RESULT AND STUDY ON THE BEHAVIOR OF THE EXTRUDED CONCRETE LINING BY TBM

Abstract

Recently, a lot of NATM tunnels have been constructed in somewhat soft ground in the city part, in order to reduce a cost of tunneling. NATM and the shield tunneling method are applied under the same ground condition and the boundary of application between both methods is not clear. Accordingly, several problems have arisen in the boundary area. For example, the basis for selection of each methods, the design method of the lining, the evaluation method of the load acting on the tunnel, etc.
In the Sambongihara Tunnel of Tohoku Shinkansen, a new tunneling method was developed. In this method, the cast-in-place concrete lining is extruded by TBM and the lining has the same role with the sprayed concrete lining of NATM.
This paper describes the behavior of the extruded concrete lining by TBM under extruding and hardening, considered by measurement result in the Sambongihara Tunnel.