Support manner null of tunnel excavation

摘要

PROBLEM TO BE SOLVED: To support only a boring wall surface part on which cracking and falling of earth take place by a liner delivered from the inside of a skin plate on a tunnel boring wall surface drilled by a tunnel boring machine. SOLUTION: A linear 1 is formed by connecting a plural number of support pieces 1, 1A, 1B in the peripheral direction inside a skin plate 11 of a tunnel boring machine 10, and this linear 1 is built in the skin plate 11. In the meantime, a boring wall surface part T' is supported by expanding the linear 1 in diameter or pushing it up immediately after the skin plate 11 by delivering the linear 1 from the inside of the skin plate 11 in accordance with drilling of the tunnel boring machine 10 in the case when a nature and a condition of a tunnel boring wall surface T are observed from the inside of the skin plate 11 as there exists the drilling wall surface part T' where cracking and falling of earth take place.