BRANCH JUNCTION PART CONSTRUCTION METHOD FOR SHIELD TUNNEL

摘要

PROBLEM TO BE SOLVED: To provide a branch junction part construction method of a shield tunnel for efficiently forming a branch junction part by joining a branch junction tunnel to a main line tunnel while directly cutting the main line tunnel with a branch junction shield boring machine. SOLUTION: The branch junction part construction method of the shield tunnel comprises a process for making the length of a major axis 13a shortest to approach the branch junction part 10, using a ramp shield boring machine 13 having a mechanism for making the length of the major axis adjustable to form the shield tunnel of approximately elliptic cross-sectional shape; a process for forming an inner wall installation section 10a by cutting a tunnel outer enclosure body 15 of the main line shield tunnel 11 in the length extended state of the major axis 13a; a process for forming a lane ensuring section 10b by cutting the tunnel outer enclosure body 15 while contracting the length of the major axis 13a onto the main line shield tunnel 11 side; and a process for making the length of the major axis 13a shortest to form a lane rubbing section 10c while further cutting the tunnel outer enclosure body 15. COPYRIGHT: (C)2007,JPO&INPIT