Sequential continuing making the multiple propulsion tubes propel from structure of the entrance for takeoff of propulsion tube, and

摘要

PROBLEM TO BE SOLVED: To provide an entrance for start of a jacking pipe, a structure of the entrance for start, and a water cut-off construction method for the entrance for start for blocking a clearance among a start pit mouth, a drilling machine, and the jacking pipe securely to cut off water in the start pit mouth.;SOLUTION: The drilling machine 5 drills previously and a plurality of jacking pipes 6 drill from the start pit mouth 2 of the jacking pipe 6 after the drilling machine 5 by connecting them sequentially to construct an underground pipeline. This structure of the entrance for start is composed of an entrance pipe 3 in which the drilling machine 5 and the jacking pipe 6 can be inserted and a sealing member 4 composed of a plurality of wire brushes 4a attached to the inner periphery of the entrance pipe 3 like a ring. The sealing member 4 is attached so as to block a clearance a among the entrance pipe 3, the drilling machine 5, and the jacking pipe 6.;COPYRIGHT: (C)2007,JPO&INPIT