The existing main pipe replaces with the new main pipe the manner

摘要

PURPOSE:To remove and recover the pipe piece of an old pipe by inserting into the old pipe a drilling machine to which a temporary pipe is attached, crushing it, replacing it by the temporary pipe, pulling out the temporary pipe, driving a recovered head and the new pipe of a back end forward and discharging the broken piece of the old pipe from the new pipe of the temporary pipe. CONSTITUTION:A temporary pipe 2 is attached to the back end of a drilling machine 5 having a drum part with a major diameter larger than an old pipe 1 buried underground, both the members are driven forward, the end of the drilling machine 5 is inserted into the old pipe 1, while it is crushed, a gap is pressed and widened and the old pipe 1 is replaced with the temporary pipe 2. Then, while the temporary pipe 2 is pulled out forward, a recovering head larger in a minor diameter than the temporary pipe 2 and a new pipe 7 fastened to the back end thereof are driven forward synchronously therewith and the pipe piece 6 of the old pipe 1 covering on the ground in the vicinity of the periphery of the temporary pipe 2 is stored in the new pipe 7 or the temporary pipe 2. Then, the pipe piece 6 and mixed earth and sand 9 are discharged from the new pipe 7 or the temporary pipe 2.