| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of base formation and sidewall protrusion prevention for a tunnel support by which the ground of the tunnel support base part can be improved easily and inexpensively. SOLUTION: The method of base formation and sidewall protrusion prevention for the tunnel support includes a drilling/steel-pipe-driving process in which a hole is drilled by a drilling bit 6 fitted to a front end of an auger rod 3 extending through a steel pipe 1 while protecting a hole wall using the steel pipe 1 as an outer pipe, and an injection process in which an grout for improvement of the ground is injected under pressure through an upper end opening part of the driven steel pipe 1 to fill the inside of the steel pipe and an outer peripheral part of the steel pipe. The auger rod 3 has a spiral blade 5 formed around the outer periphery. The blade 5 functions as a screw conveyer upon drilling to efficiently send out the slime, accumulated on a bottom part of the drilled hole, upwards, so that the bottom part of the drilled hole may also be surely filled with the grout for the ground improvement. COPYRIGHT: (C)2007,JPO&INPIT
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