UNDERWATER OBSTACLE CRUSHING DEVICE AND UNDERWATER OBSTACLE CRUSHING METHOD

PROBLEM TO BE SOLVED: To provide an underwater obstacle crushing device that can cope with a large-depth construction that it is difficult even for a rock crushing rod fall type crushing device and an underwater back hoe with a breaker to cope with.SOLUTION: An underwater obstacle crushing device is a device based upon a ground improvement ship having multiple casing pipes connected. The crushing device includes a work ship 12, a stood leader mast 14, a casing pipe 16 elevated and lowered along the leader mast 14, a vibrohammer 18 fixed to a head portion of the casing pipe, a crushing member 3 fixed to the tip of the casing pipe, a winch 21 elevating and lowering the casing pipe, and a pipe keeper portion 23 supporting the case pipe from sideway. With this invention, an underwater obstacle can be crushed in a pinpoint manner even during large-depth construction that it is difficult even for a rock crushing rod fall type crushing device and an underwater back hoe with a breaker to cope with. Depth control cannot be performed by a crushing rod fall method etc., but can be performed with this invention.