| 摘要 |
PROBLEM TO BE SOLVED: To excavate a tunnel having a sectional shape such as a circle, an oval, a triangle, a quadrilateral, etc. SOLUTION: Excavation is conducted by at least one cutter 20 installed at the front end section of a shield machine body. This shield machine has a first turning drive mechanism driving a first shaft 16 extended in the same direction as the center shaft 10 of the shield machine body in parallel with the center shaft 10 so as to be rotated around the above-mentioned center shaft, a second turning drive mechanism driving the shaft 20-1 of the above-mentioned cutter so as to be turned around the above-mentioned first shaft and a rotating drive mechanism revolving and driving the shaft of the above-mentioned cutter. |
