| 摘要 |
PURPOSE:To excavate a modification tunnel while the wall of existing tunnel is being destroyed. CONSTITUTION:The front trunk 1 of an excavator is coupled by a propulsive jack with the rear trunk 3, which is secured to the excavation wall surface by a gripper 6 installed on the rear trunk 3, and in this condition, the front trunk 1 is propelled. A pressure crush cutter 6 for ground excavation and a bit type cutter 7 are mounted on a rotary cutter head arranged at the open end of the front trunk 1, and the wall B of existing tunnel A is cut away while the bit type cutter 7 is moved in the diametric direction with enlargement and contraction. At the same time, the rock in the outer circumferential direction of the existing tunnel A is excavated by the pressure crush cutter 6, and a modification tunnel is formed as a dia. enlargement from the existing tunnel A. |
