BRANCHED SHIELD DRIVING METHOD AND SHIELD MACHINE CAPABLE OF BRANCHED EXCAVATION

摘要

PROBLEM TO BE SOLVED: To simplify and miniaturize the construction of a main-track shield machine and improve the work efficiency due to a branched start to reduce excavation costs. ;SOLUTION: A rear drum of a shield machine 1 for a main-track tunnel excavation is omitted and a plurality of shield jacks and erector devices are provided in a front drum 3 and a seal part 46 for branched start is provided in a middle drum 4. And covering members C are assembled in a vertical shaft Ta before a branch point and the driving thrust is transmitted to the drum 3 through the assembled convering members C and the plurality of shield jacks in the drum 3 using a main jack device 60 to conduct an excavation as far as the branch point, where a branch line shield machine 50 is branched and started through the part 46, and thereafter in the shield machine 1, the covering members are placed by means of the erector devices and a driving thrust is generated by the plurality of shield jacks to excavate.;COPYRIGHT: (C)1999,JPO