| 摘要 |
PROBLEM TO BE SOLVED: To prevent damages to a segment front end part forming the projected edge of a tunnel lining at the time of advancing a shield machine through a curved tunnel part by allowing only an advancing jack corresponding to the recessed edge of the tunnel lining abut to the front edge of a segment forming the recessed edge to extend, at the time of constructing the curved tunnel. SOLUTION: At the time of excavating a curved tunnel part, advancing jacks 17 respectively corresponding to space parts 4 at an arbitrary one position for coupling taper segments 2A assembled next for forming a curved tunnel lining part, and the front edges 21 of taper segments 2A with a front half projected, are kept compressed forward from the irregular front edge of a tunnel lining 3A. Other space parts 4 or advancing jacks 17 corresponding to the recessed edge of the tunnel lining are allowed to abut to the front edges 21 of the segments 2A exposed to respective space parts 4, and extended with advance reaction force supported via the front edges 21, thereby advancing a shield machine. |
