METHOD FOR FORMING COLUMNAR BODY

摘要

PROBLEM TO BE SOLVED: To reduce a variation in the strength of a columnar body due to the difference of grounds while securing the high strength of the columnar body. SOLUTION: This method for forming a columnar body in a ground includes a press-fitting step of press-fitting a spiral rod 1 having a spiral conveying screw 2 on the outside and a liquid supply passage 3 on the inside into the ground 5 while rotating in such a manner that the conveying direction of the conveying screw 2 is aligned with the press-fitting direction of the spiral rod 1 and conveying a bulk load 4 containing a hydraulic material in the press-fitting direction by the conveying screw 2 for supplying the bulk load into the ground 5 and a raising step of raising the spiral rod 1 while rotating the spiral rod in the same direction as in the press-fitting step. In at least one of the press-fitting step and the raising step, at least the water 8 is supplied into the ground 5 through the liquid supply passage 3 to cure the bulk load 4 for forming the columnar body 9. The supplied amount of water 8 is so set that a water injection rate W/C (where W is the weight of the water and C is the weight of the hydraulic material) is 20-45%. COPYRIGHT: (C)2010,JPO&INPIT