| 摘要 |
PROBLEM TO BE SOLVED: To provide a workstation type tunnel widening device and method capable of assuring the passage of general vehicles throughout the period of construction work while taking measures to prevent disasters to unrelated people, and of reducing the period and cost of tunnel widening work. SOLUTION: A protective frame 3 for protecting the passage of general vehicles is movably positioned inside an existing tunnel T and an excavating machine 5, an erector 6 and a backfilling device 7 are mounted on the protective frame 3. The excavating machine 5 widens the portion of the existing tunnel T around its cross section and digs a predetermined distance, and the protective frame 3 is moved a predetermined distance toward a working face; PC annular pieces are then assembled on the inner peripheral wall of the widened tunnel by the erector 6 to form timbering for the predetermined distance. The backfilling device 7 injects a backfilling material into a gap between the timbering for the predetermined distance where the PC annular pieces are assembled and the widened inner peripheral wall, and drilling procedures, procedures for assembling the timbering by moving the protective frame 3, and backfilling procedures are performed at every predetermined distance to construct a widened tunnel. |
