| 摘要 |
PURPOSE:To facilitate removal of extra banking concrete, by a method wherein water is poured in extra banking concrete before underwater concrete is cured, and the extra banking concrete is separated into cement paste and aggregate. CONSTITUTION:Underwater concrete 1 for a pile is placed in a vertical shaft 5 through gradual lifting up of a tremie 4 as concrete is supplied through the tremie 4 into the vertical shaft 5, and after extra banking concrete 2 is placed, the tremie 4 is pulled off. Before the underwater concrete 1 is cured, with a submerged pump 9 driven, water is poured in extra banking concrete 2 by injecting water from a water injection tool 8 through a water feed pipe. The extra banking concrete 2 is separated into a gravel layer 14, a sand layer 15, and a cement paste and slime layer 16. Further, after the underwater concrete 1 is cured and pit excavation is effected, the extra banking concrete 2 is removed. |
