Suspicious looking profile shielded tunnelling machine and suspicious looking profile excavation manner

摘要

PROBLEM TO BE SOLVED: To provide an excavation having a largely deformed cross section by providing a plurality of cutter heads, in which the ranges of excavation are partially overlapped, and disposing a cutter head oscillating mechanism to oscillate the cutter heads without causing the adjoining heads to interfere with each other. ;SOLUTION: Cutter heads 3, 4 are of the spoke type, in which four spokes 14-17 are arranged so that the adjoining spokes are disposed at a predetermined angle therebetween. And the length of the spokes 17, 17, on the inner side, is made shorter than that of the other spokes 14-16, and the spokes 17, 17 are oriented so that the tips thereof do not interfere with each other. And a preceding bit 18 is attached to each of the spokes 14-17 and a tool bit 19 is attached to each side of the spokes 14-17 to excavate a cutting face. Further an over cutter device 20 is incorporated into each of the spokes 14-16 so that an over cutter 20a projects from each forward end of the spokes 14-16 to enable the excavation of the natural ground surrounding the cutters. Thus cross sections of excavation can be freely selected so that a double circular cross section, in which the distance between the centers of the cutter heads 3, 4 can be made smaller, can be excavated.;COPYRIGHT: (C)1998,JPO