| 摘要 |
PROBLEM TO BE SOLVED: To extremely reduce working from the ground, relieve traffic congestion and trouble of neighboring inhabitants and enable execution just below a running line. SOLUTION: Main shield machines 100 are connected to both the sides of a widening shield machine 200, and an open part is formed at a prescribed position of a skin plate of each shield machine so that the inside space of each shield machine communicates therewith. Furthermore, each main shield machine 100 can be slid orthogonal to a shield axis for the widening shield machine 200. Thereby an excavation cross section can be widened and contracted orthogonal to the shield axis. |
