PILE HOLE FORMATION DEVICE

To provide a pile hole formation device capable of improving accuracy of a measurement value of ground strength.SOLUTION: A pile hole formation device comprises: a solidification material force-feed pipe 53 vertically extending in a hollow part of a tip auger rod; a penetration rod 52 provided in the tip auger rod so as to be vertically movable; a steady brace that is connected to the penetration rod 52 to inhibit the penetration rod 52 from moving in a horizontal direction; a measurement cone 51 connected to a lower end of the penetration rod 52; a hydraulic cylinder that is provided in the tip auger rod and lowers the penetration rod 52 to push out the measurement cone 51 to the outside of an auger head 30 and make the measurement cone penetrate into the ground; and a three-component sensor 54 that is positioned between the penetration rod 52 and the measurement cone 51 and measures resistance force in making the measurement cone 51 penetrate into the ground.SELECTED DRAWING: Figure 3 【課題】地盤強度の測定値の精度向上を図ることが可能な杭孔形成装置を提供する。【解決手段】杭孔形成装置は、先端のオーガロッドの中空部内を上下方向に延びる固化材圧送管５３と、先端のオーガロッド内に上下移動可能に設けられた貫入用ロッド５２と、貫入用ロッド５２に接続され、貫入用ロッド５２の水平方向の移動を抑制する振れ止めと、貫入用ロッド５２の下端部に接続された測定コーン５１と、先端のオーガロッド内に設けられ、貫入用ロッド５２を下方に移動させ、測定コーン５１をオーガヘッド３０の外部に押し出して地盤内に貫入させる油圧シリンダと、貫入用ロッド５２と測定コーン５１との間に位置し、測定コーン５１を地盤内に貫入させる際の抵抗力を測定する３成分センサ５４とを備える。【選択図】図３