Piling hammer and underwater piling construction method null for underwater

摘要

PURPOSE:To improve accuracy and facilitate construction supervision by adapting a constitution wherein a through hole is formed along its axial center in a pile driving hammer equipped with a ram driving device, and driving the hammer after mounting it on a guide pipe in a way freely movable up and down. CONSTITUTION:A device to move a ram 14 up and down and a device to trans mit percussion force to a pile through an anvil 16, etc., are installed in the cylindrical casing 10 of a pile driving hammer 4, and a hole is provided along its axial center through which a guide pipe 5a penetrates. Wires 3a, 3b are wound down to immerse the underwater pile driving hammer 4 in water 8. After a pile 5 was erected at the bottom of the water and the pile 5 was driven down to a specified depth with the hammer 4, the hammer 4 is received in a work board 1 and the guide pipe 5 is cut off. Therefore, the accuracy is good and construction supervision becomes easy. Moreover, it becomes unneces sary to lengthen a pile driving leader 2 in accordance with water depth, or cut off a driven pile, so that the pile driving boat 1 can be made smaller.