Method of driving and forming a tunnel with hydraulic boring machine

Abstract

A tunnel driving and forming method with hydraulic boring machine through mixed ground of stable and unstable layers which is simplified in equipments, less in air contamination and noises and high in working accuracy. The method comprises steps of driving the hydraulic boring machine into the ground to bore a tunnel therein, installing segments sequentially against bored tunnel wall right behind the machine as the same advances, impregnating a back-filling agent between said bored tunnel wall and outer periphery of installed segments, removing the rearmost set of a certain number of sets of said installed segments behind the machine for circulatory use as long as the ground bored is stable, reinforcing exposed surface of said back-filling agent impregnated and set, and repeating respective said steps responsive to advances of the machine. The removed sets of the segments are normally circulatorily used as sequentially installed at the foremost position of said certain number of sets adjacent tail end of the machine so long as the ground being bored is stable but, when an unstable ground layer is reached, the installed segments at the position facing such unstable layer are remained as installed so as to be a reinforcing wall for the unstable layer.