| 摘要 |
PROBLEM TO BE SOLVED: To provide a ground injection method of easily closing a gap between an outer pipe and a drill hole in a short time without fail to surely prevent a leakage of an injection material to the ground. SOLUTION: An injection pipe 10 is used in executing the ground injection method. The injection pipe 10 consists of an inner pipe 11 and an outer pipe 13 that are arranged to be coaxial with each other, and has a drill blade 15 on the tip. The inner pipe 11 has an injection material discharge opening 12 for discharging an injection material 7, and the outer pipe 13 has an air discharge opening 14 for discharging air 4 that is disposed above the injection material discharge opening 12. The drill blade 15 of the injection pipe 10 bores the drill hole 2 in an improved ground 1, and the air 4 is discharged from the air discharge opening 14 of the injection pipe 10 into the drill hole 2 to cause the convection of fine grains 5 contained in the original ground in water 3 collected in the drill hole 2. By utilizing a phenomenon of sedimentation of the fine grains 5, a gap H between the injection pipe 10 and the drill hole 2 is partially blocked with the fine grains 5 in an area ranging from the air discharge opening 14 of the injection pipe to the injection material discharge opening 12. The injection material 7 is then discharged from the injection material discharge opening 12 of the injection pipe 10 and is injected into the improved ground 1 to improve the ground 1. COPYRIGHT: (C)2010,JPO&INPIT
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