| 摘要 |
PURPOSE:To improve the drilling performance by arranging the preceding side cutter head of a cutter head movably and adjustably in the longitudinal direction with cutter shafts having expansion mechanisms. CONSTITUTION:A shield machine is propelled, and a preceding side cutter head 15a and a succeeding side cutter head 15b are rotated and driven by rotary driving devices 18a, 19a, 18b, 19b via cutter shafts 21a, 21b, 14. Muddy water is force-fed into cutter chambers 13a and 13b to start drilling. The cutter shafts 21a and 21b with expansion mechanisms 23a and 23b are extended, and the longitudinal difference between the preceding side cutter head 15a and the succeeding side cutter head 15b is increased for drilling. |
