STRENGTH DESIGN METHOD AND BACK-FILLING METHOD

To provide a method for strength design of ground improvement material in a back-filling area.SOLUTION: A method for strength design of ground improvement material comprises: a step manufacturing a first test piece which a field soil sample and a first improvement material contact; a step contacting the field soil sample to a second improvement material; a step manufacturing a second test piece of which strength is different from the first test piece; a step forming a first drilling hole and a second drilling hole by different rotation rates of excavation buckets from each other in a boundary between the field soil sample and the first improvement material; a step forming a third drilling hole and a fourth drilling hole by different rotation rates of excavation buckets from each other in a boundary between the field soil sample and the second improvement material; a step measuring bending degree of the first drilling hole to the fourth drilling hole; and a step identifying the relation between the bending degree, the rotation rates of the excavation buckets, the strength of the first improvement material and the strength of the second improvement material.SELECTED DRAWING: Figure 1 【課題】埋め戻し部における地盤改良材の強度設計を行う方法を提供する。【解決手段】現場土試料と第１地盤改良材とが接する第１供試体を作製し、現場土試料と第２地盤改良材とが接し、第１地盤改良材と強度が異なる第２供試体を作製し、現場土試料と第１地盤改良材との境界において、掘削バケットの互いに異なる回転数で、第１掘削孔及び第２掘削孔を形成し、現場土試料と第２地盤改良材との境界において、掘削バケットの互いに異なる回転数で、第３掘削孔及び第４掘削孔を形成し、第１掘削孔乃至第４掘削孔の曲がりの程度を測定し、測定結果に基づいて、曲がり程度と、掘削バケットの回転数と、第１地盤改良材の強度及び第２地盤改良材の強度と、の関係を特定する。【選択図】図１