Development of a Precast Concrete Lining Technique Using Prestressed Concrete Structures

摘要

In recent years various methods of shield tunnelling in urban areas of Japan have been studied to improve heading stability and reduce ground movement. However, the machinery and the lining production costs involved are generally expensive. The authors have developed the Prestressed and Precast Concrete Segmental Lining (P&PCSL), which can achieve the required performance at an economical cost, owing to its effective structural design. The P&PCSL provides a prestressed concrete structure by tensioning and anchoring the unbonded prestressing steel after its installation into the winding sheath within the precast concrete. The unbonded prestressing steel decreases the friction loss of tensioning so that the anchoring position is at only one location on the lining annulus.