From the heading surface of intersection slit excavation

摘要

PROBLEM TO BE SOLVED: To provide a method of excavation construction, by which vibrations and noises can be reduced by non-blasting and which has excellent excavation efficiency. ;SOLUTION: Slits 8 are formed to a ground not excavated on the opposite side from the facing surface 1 of a tunnel in the transverse direction of the tunnel, and bedrocks 9 in regions among the slits 8 and the facing surface 1 are excavated by applying an impact to the facing surface 1. Accordingly, vibrations and noises are reduced by non-blasting and the ground can be excavated safely while excavation efficiency is improved and execution cost can be curtailed.;COPYRIGHT: (C)1997,JPO