PROBLEM TO BE SOLVED: To provide driving rotary type sheet presser piles that can be rotated and embedded in soil while preventing wrapping of a sheet material by driving of the upper end of the pile and can pin the sheet material to soil firmly.SOLUTION: A pair of spiral protrusions 7, 7 are protruded to a peripheral surface portion 6 of a bar-like pile body 5, in the opposing state and in the twisted state of the same direction. The portion on the lower end side of the pile body 5 is defined as a tapered portion 11. In the upper side portion of the tapered portion 11, the protrusion amounts of the spiral protrusions 7, 7 are set equally, their twist angles being set to 60 to 80 degrees. In the tapered portion 11, the twist angles of the spiral protrusions 7, 7 are gradually increased from the upper ends to the lower ends. And the protrusion amounts are gradually decreased, and the protrusion amounts at their lower ends are set to zero. The spiral protrusions 7, 7 constitute edges 17, 17 in the tapered portion 11, and their lower end side portions are defined as vertical edge portions 20, 20 having twist angles of 80 to 90 degrees. The lengths of the vertical edge portions 20, 20 are larger than the thickness of a sheet material 3.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】杭上端を打圧することにより、シート材の巻き付きを防止しつつ回転して土中に埋入でき、シート材を地面に確実に止着し得る打ち込み回転式のシート材押え杭を提供する。【解決手段】棒状の杭本体５の周面部６に一対の螺旋突条７，７を対向状態に且つ同一方向の捩れ状態で突設する。杭本体５の下端側の部分は先細部１１とする。先細部１１よりも上側の部分では、螺旋突条７，７の突出量を等しく設定し、その捩れ角度を６０～８０度に設定する。先細部１１においては、上端から下端に向けて、螺旋突条７，７の捩れ角度を次第に大きくする。且つ、その突出量を次第に小さくし、その下端における突出量はゼロとする。螺旋突条７，７は、先細部１１において切刃部１７，１７を構成し、その下端側部分は、捩れ角度が８０～９０度である垂直状切刃部２０，２０とする。垂直状切刃部２０，２０の長さは、シート材３の厚さよりも大きい。【選択図】図１
