TUNNEL REINFORCING CONSTRUCTION METHOD, TUNNEL REINFORCING SYSTEM CAPABLE OF FIXING NEARBY NATURAL GROUND WITH METALLIC ROD, WORK EXECUTION METHOD FOR TUNNEL WALL IN THE CONSTRUCTION METHOD, AND TUNNEL WITH REINFORCED TUNNEL WALL

摘要

PROBLEM TO BE SOLVED: To increase the strength of the nearby natural ground and maintain proper safety by driving a metallic rod into the natural ground around a tunnel through a projection device using the high pressure compressed air, and fastening the rod with a frictional force. ;SOLUTION: Metallic rods 1, 2 and so forth such as a rock bolt or a steel reinforcement are driven into the natural ground around a tunnel through a projection device, using the high pressure compressed air, and fixed to the natural ground around the tunnel via a frictional force. In this case, a plurality of metallic rods 2 are radially driven from a zone 4 previously excavated. Also, a metallic rod 1 is driven into an excavation work zone 3 in slantwise upward direction from a position corresponding to the upper surface of the tunnel, depending on the condition of the natural ground. Furthermore, an excavation work is developed with the rod 1 kept in a fixed state. Thereafter, the external surface of the tunnel is strengthened with sprayed concrete, and the rod 1 is fixed to the natural ground via a frictional force.;COPYRIGHT: (C)1997,JPO