EXTENSIBLE/CONTRACTIBLE CUTTER OF TUNNEL EXCAVATOR AND EXCAVATION METHOD FOR DEFORMED CROSS SECTION TUNNEL BY USE OF THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an extensible/contractible cutter of a tunnel excavator capable of preventing a side face of a movable rod coming into slide-contact with a bearing from being worn due to sediment, holding normal operation for a long period of time, and achieving excellent durability and to provide an excavation method for deformed cross section tunnel by use of the cutter.;SOLUTION: In this excavation method for excavating a tunnel having a cross section other than a circular cross section by reciprocating and moving the movable rod 13 supported on the bearing 27 while rotating a cutter frame 5, the movable rod 13 is reciprocated and moved for a guide cylinder 12 within a scope where an inner peripheral face of a protective cylinder 22 is abutted on a seal 25, and the seal 25 prevents sediment from intruding into the inside of the protective cylinder 22 while covering an outer peripheral face of the movable rod 13 with the protective cylinder 22 and a lid part 23 during its reciprocating movement to prevent the outer peripheral face of the movable rod 13 from being exposed to sediment.;COPYRIGHT: (C)2011,JPO&INPIT