CONCRETE PLACEMENT SYSTEM AND ITS METHOD FOR PERFORMANCE SPACE AT TUNNEL CREST

PROBLEM TO BE SOLVED: To provide a concrete placement system which is most suitable for the performance space 3C at a tunnel crest part.SOLUTION: A concrete placement system in this invention comprises: a concrete placement pipe 10, which extends along the axial direction of a tunnel, having a discharge port at its tip; and a placement-pipe feeding device 20, which supports the base end side of the concrete placement pipe 10, and pushes the tip of the concrete placement pipe 10 along the axial direction of the tunnel from the outside of a performance space 3C at the crest part of the tunnel into the inside, or pulls the same out from the performance space. A pressure sensor 32 is installed either on the concrete placement pipe 10 or the placement-pipe feeding device 20, and detects the concrete-filling pressure which is caused on the concrete placement pipe 10 in the direction of pushing it back. The placement-pipe feeding device 20 is controlled to move the concrete placement pipe 10 backward according to the filling pressure detected by the pressure sensor 32.