RECOVERING METHOD FOR EXISTING BURIED PIPE

摘要

PROBLEM TO BE SOLVED: To easily recover an existing buried pipe from inside the ground when the buried pipe is replaced with a newly laid pipe. SOLUTION: An existing underground buried pipe 11 is cut at proper circumferential positions in a pipe axis direction, and the buried pipe 11 is radially constricted via the cutting places so as to be spaced from sediment 12 about the burial region before the radially constricted buried pipe 11 is removed from inside the ground. A first radial constrictor 19 is movable along the line of the existing underground buried pipe 11 cut circumferentially in two in a pipe axis direction and has a first radially constricting guide passage for deforming or constricting one section 16A radially with the movement. A second radial constrictor 20 has a second radially constricting guide passage for deforming or constricting the other section 16B radially over the one radially constricted section 16A with the movement.