Large metropolitan cities such as Tokyo, Japan demand to develop more efficient utilization of expressway networks to reduce the traffic congestions. However, the land surface area available for the new infrastructure construction is limited and the only possible space left is an underutilized space beneath the ground.
To overcome the traffic problem in Tokyo, the construction of 8km long underground expressway, Central Circular Shinagawa Route, Tokyo Metropolitan Expressway is now underway. For the construction of this route, shield tunneling method was employed and the steel segments are used for the shield tunnel connection with ramp tunnel. In order to rationalize design of the steel segment, we currently developed and employed a new Steel-Reinforced Concrete Composite Segment (referred to as “composite segment”) for a part of ramp tunnel structure where the high structural rigidity is required.
This paper introduces the structures of the composite segment for shield tunnel and the results of four laboratory experiments to verify the structural performance of the composite segment. The experiments with full scale models are carried out to examine the load-carrying capacity, the performance of the joint between the composite segments due to bending, splicing effects on the joint between the composite segment and the steel segment and fire resistance of the composite segment against RABT-60 minutes thermal curve.