SHIELD TUNNELING MACHINE AND TUNNEL EXCAVATING METHOD

摘要

Shield excavation devices (11) are arranged in a body (2) with a rectangular cross-section so as to be individually movable in the front-rear direction. The shield excavation devices (11) are each formed in a substantially square excavation cross-section and are arranged in the body in two stages in the up and down direction and four rows in the left and right direction. A cutter head (18) provided on each of the shield excavation devices is constructed from a rotating shaft section (18a) and three arm-like cutter sections (18b). The rotating shaft section (18a) is rotatably mounted on a rotating plate (16) that is eccentrically rotatably provided at the center of a shield body (12) of the excavation device. The cutter sections (18b) are radially projected at equal intervals on a front end section of the rotating shaft section. The rotating plate body and the rotating shaft section are individually rotated in the opposite directions at a rotation ratio of 3:4, enabling a square-shaped tunnel to be excavated.