Construction method of tunnel invert and precast plate for tunnel invert

摘要

PROBLEM TO BE SOLVED: To provide a construction method of a tunnel invert which is excellent in workability and excellent in strength against earth pressure.SOLUTION: In a construction method of a tunnel invert in which a concrete invert 5 is provided at a bottom of an existing tunnel 1, since the invert 5 having a width of the tunnel 1 is formed by a precast board 6, the plurality of precast boards 6 are formed, the bottom part of the tunnel 1 is excavated, and the precast board 6 is installed at an excavated part 31, it is possible to form the invert 5 by disposing the plurality of precast boards 6 at the excavated part 31 of the existing tunnel 1. Since the precast board 6 is an integral body having the width of the tunnel 1, the invert 5 is easy to install because there is no joining portion, and is excellent in strength against the earth pressure applied after construction.SELECTED DRAWING: Figure 1