| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the occurrence of iron loss at a center push pipe portion caused by the leaking magnetic flux from a power cable and to prevent power loss in a power tunnel constructed by the jacking method. SOLUTION: Longitudinal nonmagnetic metal members 3b and 5b are provided at one position on the circumference of the steel portion of a center push outer pipe 1, and a regulating angular rod 31 is provided on the inner periphery. Longitudinal nonmagnetic metal members 14b, 15b, 19b are provided at one position on the circumference of the steel portion of a center push inner pipe 2, and guide plates 32 and 32 coupled with the regulating angular rod 31 are provided on the inner periphery. When the center push outer pipe 1 and the center push inner pipe 2 are coupled, the nonmagnetic metal members 3b and 5b are brought into contact with the nonmagnetic metal members 14b, 15b, 19b, the regulating angular rod 31 is coupled with the guide plates 32 and 32, thereby the relative rotation in the peripheral direction of the center push outer pipe 1 and the center push inner pipe 2 is prevented.</p> |
