Road widening drilling rig and road widening excavation manner null of excavation

摘要

PROBLEM TO BE SOLVED: To provide a widening excavator of an excavated ditch capable of making widening excavation even if an embedding width of the ground for embedding an underground installation held with the excavated ditch is directly under the wide ground without specially improving on the conventional widening excavator and a widening excavation method of the excavated ditch by the widening excavator. ;SOLUTION: A reaction member 50 and an excavation guide member 54 are erected in the existing excavated ditch, and the excavation guide member 54 includes a frame body 56 bearing an excavation section T having an excavation shaft 58 rotated by driving force of a hydraulic motor 53 as rotational driving source and capable of being pivoted by driving force of a hydraulic cylinder 55 as pivotal driving source. In an excavator U1 capable of raising and lowering the framce body 56, it includes a screw shaft S held in a joint site between the basic end of the excavation shaft 58 in the excavation section T and hydraulic motor 53 in a detachable manner and used as an excavation shaft extension device capable of making widening excavation of the existing excavated ditch by means of the excavation shaft 58 while transferring the driving force of the hydraulic motor 53.;COPYRIGHT: (C)1999,JPO