| 摘要 |
PROBLEM TO BE SOLVED: To provide the method and equipment for creating a further denser drain column consisting of a number of granular substances. SOLUTION: A drain column 39 is formed by arranging a hollow body 14 underground which permits expansion and shrinkage by the supply and discharge of a high pressure fluid, repeating a process of sudden expansion and shrinkage, repeating a process of supplying a number of granular substances between the hollow body and surrounding ground 38 during shrinkage or after shrinkage, thereafter alternately repeating the rise of the hollow body, expansion and shrinkage of the hollow body at the rise position and the supply process of granular substances. The hollow body is arranged underground by penetrating a cylindrical casing 12 housing a sheet member 38 fixed to a pipe member. Supply of the granular substances is performed by placing them in the casing above the ground.
|
