DESIGN METHOD OF WIDENING PILE

To provide a design method of a widening pile capable of rationally determining a pile shape.SOLUTION: A design method of a widening pile has an initial value setting step of setting initial values of a shaft diameter and a widening diameter, an extraction resistance force calculation step of calculating an extraction resistance force (Q) of a widening part required from an external force condition using a reference stress (σstd) calculated from expression (1), a first shape determination step of determining whether the initial values satisfy any one of expressions (2) and (3), a shape changing step of changing at least one of a widening angle, an excavation depth and a widening diameter, when it is determined in the first shape determination step that the initial values do not satisfy the expressions, and a second shape determination step of determining whether the initial values satisfy any one of the expressions (2) and (3) after the shape changing step. When it is determined in the second shape determination step that the initial values do not satisfy the expressions, the method returns to the shape changing step.SELECTED DRAWING: Figure 11 【課題】杭形状を合理的に決定できる拡幅杭の設計方法【解決手段】軸径および拡幅径の初期値を設定する初期値設定工程と、外力条件から要求される拡幅部の引抜き抵抗力（Ｑ）を式（１）から算定される基準応力（σｓｔｄ）を用いて算定する引抜き抵抗力算定工程と、初期値が式（２）および（３）のいずれかを満たすかを判定する第１形状判定工程と、第１形状判定工程でいずれも満たさないと判定された場合に、拡幅角度、掘削深度および拡幅径の少なくとも１つを変更する形状変更工程と、形状変更工程の後に式（２）および（３）のいずれかを満たすかを判定する第２形状判定工程と、を有し、第２形状判定工程でいずれも満たさないと判定された場合には、形状変更工程に戻る。TIFF2024006686000008.tif49170【選択図】図１１