| 摘要 |
<p>PURPOSE:To perform sheathing and water stop at an underground joint in short time with low cost by supporting the natural ground around the underground joint by means of the ring type outer circumferential section of a rotary cutter and the hood sections of first and second shield drill machines lapped over the ring type outer circumferential section. CONSTITUTION:A rotary cutter 5 is mounted onto a first shield machine 1 while being lapped over the inner circumference of a hood 3a, and a rotary cutter 6 having outer diameter shorter than the inner diameter of a hood section 4a is mounted retractably into the hood section 4a onto a second shield drill machine 2. When underground joint is made, the rotary cutter 6 is retracted and the first drill machine 1 advances while drilling natural ground with the rotary cutter 5 thereof thus lapping a portion of the outer circumferential section 5a of the rotary cutter over the inner circumference of the hood section 4a of the second drill machine 2. Then natural ground around the underground joint is supported by the hood sections 3a, 4a of both machines and the outer circumferential section 5a of the rotary cutter of the first drill machine 1 and a tunnel is communicated.</p> |
