| 摘要 |
PROBLEM TO BE SOLVED: To provide a tunnel construction method capable of safely executing excavation work by a construction machine, by lengthening the length in the direction along the central axis of a cylinder of a cylindrical outer shell for surrounding sediment excavated by the construction machine.SOLUTION: The tunnel construction method comprises an outer shell installation step of forming and installing the cylindrical outer shell 2C on the natural ground 10 by successively connecting a succeeding pipe to the rear of a propelled forefront cylindrical body 2A, by forming and propelling the forefront cylindrical body 2A in and to the natural ground 10, by mutually adjacently arranging a plurality of pipes (the forefront pipe 6) having excavation means on the tip side of the pipe, along the outer peripheral edge of a tunnel to be excavated, an excavation step of excavating the sediment inside of the outer shell 2C of cutting the edge from the outside natural ground 10, an outer shell propulsion step of propelling the outer shell 2C of an excavation-finished part by the excavation step and a timbering forming step of forming a timbering 12 on a tunnel wall surface positioned in the rear of the outer shell 2C after propelling the outer shell 2C by excavating the sediment inside of the outer shell 2C. |
