EXTENSION SECTION CONSTRUCTION METHOD AND CONFLUENCE SECTION CONSTRUCTION METHOD FOR TUNNEL, AND SEGMENT

摘要

PROBLEM TO BE SOLVED: To construct an expansion section, such as a confluence section, of a tunnel without a need of a device for a shield machine.;SOLUTION: The linings are assembled, which include segments 3 and 7 that are in upper and lower portions and that can be projected to the outer peripheral side of a main line tunnel 1 and a branch line tunnel 5 dug in almost parallel with each other. The underground soil between the linings is dug, and the underground soil at the outer peripheral side of the upper and lower portion segments 3 and 7 is dug to form a cavity. Subsequently, the upper and lower portion segments 3 and 7 are pushed out from the inner peripheral side to project into the cavity. Then, a connecting member 9 bridging the upper and lower portions is disposed between the upper and lower portion segments 3 and 7 projecting into the cavity to construct a tunnel confluence section.;COPYRIGHT: (C)2008,JPO&INPIT