| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an adit construction method with which a space can be secured at the back of a follower. <P>SOLUTION: According to an adit construction method utilizing a departure facility D provided within an existing tunnel A, a follower 5 abutted to a rear end face of a following box 2 is disposed at the back of a departure port and after a connection material 8 from an opening edge of the departure port to the follower 5 is disposed, a tensile force is applied to the connection material 8 by a jack 6 which is mounted to the follower 5, thereby moving the follower 5 to the side of the departure. Therefore, a leading box 1 and the following box 2 are extruded from the departure port. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
