CONSTRUCTION METHOD OF LARGE CROSS SECTION TUNNEL AND EXCAVATION DEVICE FOR LARGE CROSS SECTION TUNNEL

摘要

PROBLEM TO BE SOLVED: To provide a construction method of a large cross section tunnel which can reduce a construction cost by efficiently constructing the large cross section tunnel in a short period, and an excavation device for the large cross section tunnel.;SOLUTION: A first expansion rectangular propulsion pipe 5 having a contour shape corresponding to a contour of a first excavation unit is installed in the ground by a propulsion jack while developing a propulsion pipe excavation hole by using the first excavation unit which is formed by connecting a plurality of excavators in parallel with one another in a horizontal direction or a vertical direction. The first expansion rectangular propulsion pipe 5 has a substantially-oblong frame shape vertical to an extension direction in a cross section, and reinforced by installing a temporary columnar support 9 at its middle part in a longitudinal direction. Also, the plurality of first expansion rectangular propulsion pipes 5 and a plurality of rectangular propulsion pipes 11 are installed at up-and-down two stages in parallel with each other, and the first expansion rectangular propulsion pipes 5 and the rectangular propulsion pipes 11 are connected and integrated to each other by a joint part, thus constructing a lining body 12. By removing a portion not related to a structure of the large cross section tunnel 13 from a small cross section tunnel of the lining body 12, the large cross section tunnel 13 is constructed.;SELECTED DRAWING: Figure 4;COPYRIGHT: (C)2019,JPO&INPIT