| 摘要 |
PROBLEM TO BE SOLVED: To provide a construction method for an underground structure capable of constructing the underground structure comprised of a small-cross-section tunnel group even if a vertical shaft is not constructed. SOLUTION: This is a method for constructing a widened part 100 by surrounding a natural ground 6 with a small-cross-section tunnel group 10 coupled with side surfaces of a plurality of small-cross-section tunnels 111,121,131 and 141 and by excavating the surrounded natural ground. After excavating with a shield machine 21 which is provided with a plurality of small-cross-section shield machine, the plurality of small-cross-section tunnels is constructed with intervals by excavating with the plurality of small-cross-section shield machines toward one of the end 100a of the both ends 100a and 100b in a longitudinal direction of the widened part 100 and similarly by excavating toward the other end 100b so that the small-cross-section tunnel group coupled with the side surfaces is formed by constructing a small-cross-section tunnel 131 between a small-cross-section tunnel 111 previously constructed. COPYRIGHT: (C)2008,JPO&INPIT |
