| 摘要 |
<p>PURPOSE:To permit a tunnel of optional cross section to be excavated by a method in which the locuses of the tips of fixed long spokes do not lap on each other in a spoke-type cutter device but the locuses of the tips of extendable spokes extended do. CONSTITUTION:In the cutters A of a shield excavator having spoke-type cutters A set on the same plane, fixed long spokes 2 and extendable spokes 3 are provided. The spoke 2 has cutters 4 over its whole length and the spoke 3 is designed to the separately extended or contracted and has cutters 6 on its tip at least. The distance between the adjacent cutters A is set up in such a way that the locuses of the tips of the spokes 2 do not lap on each other but the locuses of the tips of the spokes 3 in the extended state do.</p> |
