Vertical shaft drilling apparatus and vertical drilling method

摘要

To provide a vertical shaft excavating apparatus capable of easily excavating the hard ground when reaching a hard ground during construction of a caisson frame.SOLUTION: This device excavates the bottom ground including the lower edge of the caisson frame. A base member 6, and trencher type excavating heads 7 A, 7 B arranged on the base member 6. The movable excavating head 7B is of a movable type and downward excavation which allows the excavation to go downward is enabled in a state where both excavating heads 7A and 7B are in the vertical attitude position. By swingingly displacing the movable excavating head 7 B to the deployed position P 2 in a state in which the two excavating heads 7 A and 7 B are penetrated into the ground in the vertical attitude position, the excavating head 7 B at the lower part Enlarged excavation that enables widening is possible.(FIG.