| 摘要 |
PURPOSE:To enhance the continuous construction by the same shield machine by rotating a shield at a determined angle by the drive of an initial rotating jack and the separation of an inner shell and an outer shell at an adit depth, fixing the inner shell to a front outer shell for cut-off processing, and then horizontally excavating. CONSTITUTION:A front shield 10 is rotatably and separatably connected to a rear shield 20 and advanced by obtaining the reaction from an existing segment while excavating downward, and a segment 30 is assembled in the rear shield 20 to extend a shaft A. The turning range is over cut by a copy cutter 15 slightly short of the constructing depth of an adit, and a segment of one ring portion is assembled in the front shield 10. The shield is rotated at 90 deg. by the drive of a rotating jack 29 and the release of the fixation between an inner shell 22 and an outer shell 21, and concrete is charged in the excessive excavation space. Further, the inner shell 22 is fixed to a front outer shield 12 by welding for cut-off processing, and a shield body 11 is advanced for excavation with the front outer shell 12 being left to construct an adit B (not shown). Hence, high cut-off property can be ensured at the time of rotating the front shiled, while both the shaft and the adit can be continuously constructed by the same shield machine. |
