| 摘要 |
PROBLEM TO BE SOLVED: To reduce a departure space, and to conduct excavation works easily by installing front side supports on the outer circumferential side in the same radial direction to bearings supporting a cutter head. SOLUTION: A cutter head 5 is mounted rotatably on a front section, and a main frame 2 supporting the cutter head and a gripper frame 3 bearing a gripper are connected by thrust jacks 11. In the tunnel excavator 1 having such constitution, front side supports 7, 7 supporting the main frame 2 to a bedrock are set up on the outer circumferential side in the same radial direction to bearings 8 bearing the cutter head 5. The tunnel excavator 1 is loaded on a frame for departure and carried into the place of departure, and the frame for departure is started while obtaining gripper reaction and propulsive reaction in the frame for departure. Accordingly, when a connecting tunnel for two existing tunnels is excavated, a small departure space may be used, and the overall width of the tunnels is not closed even during excavation works. |
