UNDERGROUND PILE CRUSHING METHOD

To propose an underground pile crushing method that has further reduced generation of vibration, noise and dust so that the method can be used at city center.SOLUTION: An underground pile crushing method comprises: a process to drill a crushing agent charging hole from a pile head of an underground pile along lengthwise direction of the underground pile in a state where the pile head is exposed; a process to insert the crushing agent and a cement tamper alternately in a multistage manner along the lengthwise direction of the underground pile in the crushing agent charging hole from the pile head so that the crushing agent is placed at certain intervals; and a process to ignite the crushing agent inserted in a multistage manner and crush the pile at certain intervals in a range between 0.025 and 0.5 second sequentially from the pile head toward a bottom part of the underground pile.SELECTED DRAWING: Figure 1 【課題】都心等における利用にも耐えられるように、振動と騒音と粉塵の発生をより低減した地中杭破砕方法を提案すること等を目的とする。【解決手段】杭頭が露出された状態の地中杭に、地中杭の長さ方向に沿って杭頭から破砕薬装填孔を穿孔する工程と、杭頭から、破砕薬装填孔に、破砕薬とセメントタンパーとを交互に、破砕薬が一定の間隔となるように、地中杭の長さ方向に沿って多段に挿入する工程と、多段に挿入された破砕薬を、杭頭から地中杭の底部に向けて順次に、０．０２５秒〜０．５秒の範囲の一定時間毎に、着火して破砕する工程と、を有する地中杭破砕方法とする。【選択図】図１