BEDROCK REINFORCING METHOD AND GROUTING DEVICE USED THEREFOR

PROBLEM TO BE SOLVED: To provide a bedrock reinforcing method capable of efficiently reinforcing a bedrock with fewer feed pipes when a tunnel excavation is carried out by a mountain tunneling method and a grouting device used therefor. SOLUTION: As a first progressive angle, for example at the same about 20° of an angle of elevation as usual, the feed pipe 4 is driven about 1m into the obliquely forward bedrock 3 along a tunnel circumference 2 from a cutting face 1, and then, as a second progressive angle in the direction of the tunnel excavation nearer than the first progressive angle from partway through the driving, for example at the approximately horizontal (about 1° of an angle of elevation), the feed pipe 4 is driven about 2m. Since the feed pipe 4 is installed by concentrating within a range of an influence on the excavation, the bedrock can be usefully reinforced by making use of the fewer feed pipes 4. Since the feed pipe 4 is installed in a position nearer to the direction of the tunnel excavation forward of the cutting face 1, there is no unimproved part forward of the cutting face 1 to cut down overbreak. COPYRIGHT: (C)2005,JPO&NCIPI