DRILLED HOLE PRECISION CORRECTING METHOD AND DRILLED HOLE PRECISION CORRECTING DEVICE

摘要

PROBLEM TO BE SOLVED: To form an objective drilled hole by simply making a correction even when a plurality of drilling shafts are twisted as a whole during an excavation.;SOLUTION: The ground 2 is drilled while a plurality of drilling shafts 1 aligned in a line in the lateral direction are rotated. When the tip sections of the drilling shafts 1 are twisted as a hole and rotated and drifted as a whole from the normal position in plan view during the excavation, the rotating direction of the drilling shaft 1 giving the rotating force in the drift, direction is changed in the opposite direction, and the drilling shafts 1 are rotated and returned in the opposite direction to the twisting direction as a whole.;COPYRIGHT: (C)2002,JPO