| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To enable a new pipeline with a diameter as large as or larger than that of an existing pipe to be laid by replacing the existing pipe with the new pipeline in a non-cut-and-cover tunneling method, and to enable the new pipeline to be linearly laid without being affected by a step, unevenness and meandering even in the presence of the step, the unevenness, the meandering, etc. in the existing pipe. <P>SOLUTION: This pipeline replacing method is practiced by repeating: a step of leading a leading body 10 into the existing pipe from one mouth of the existing pipe to be replaced, crushing a section of the existing pipe 20 around the leading body by enlarging the diameter of the leading body, reducing a diameter of the leading body and advancing the leading body over an existing-pipe crushing range, inserting a new-pipeline unit body 60a into a guide pipe 50 which is connected to the rear part of the leading body, and after that, further leading a united unit of the leading body and the guide pipe into an uncrushed section of the existing pipe, while maintaining a state wherein the guide pipe and the new pipeline unit body are fitted together; and a step of crushing the existing pipe section around the leading body by enlarging the diameter of the leading body, and connecting another new pipeline unit body to the rear of the new pipeline unit body. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
