IMPROVING METHOD FOR GROUND OF TUNNEL EXCAVATION PART AND PERIPHERAL PART THEREOF

摘要

PURPOSE: To perform improvement of the peripheral ground of a tunnel by the less number of man powers and with a short term of works by a method wherein in prior to excavation of a tunnel, injection for a chemical and timber ing based on a lock bolt method are simultaneously executed. ;CONSTITUTION: A heading 3 is previously excavated and built below a tunnel 2 to be excavated. Outer pipes 11 for injection are driven from the interior of the heading 3 such that the outer pipe is driven over the cross section of the tunnel 2 to be excavated and down to a given depth in the ground of the peripheral part of the tunnel. By using an inner pipe for injecting a double packer introduced in the outer pipe 11 for injection, chemicals are injected in a ground. A high strength part 11A of the outer pipe 11 for injection is caused to remain in a drive position. Simultaneously, by a high strength fixing agent injected in the outer peripheral part of a part 11a for fixing of the high strength part 11A to fill the outer peripheral part with the fixing agent, the part 11a for fixing is fixed in a drive position. By repeating above process, a plurality of ground improved parts (a) are built to the whole of the periphery of the tunnel.;COPYRIGHT: (C)1995,JPO