| 摘要 |
<p>PURPOSE:To simultaneously insert a plurality of new pipes in a single replacing operation and accomplish smooth works and cost suppression by grouping old pipes, and inserting new pipes having larger dia. than the old ones in such a way as fitted on the respective old ones. CONSTITUTION:A plurality of new pipes 5 having a larger dia. than the old pipes 4 laid underground are put parallelly and consolidated by welding etc. to form a group of new pipes 5G. A plurality of adjoining old pipes 4 of those embedded in multiple strips are grouped to form a pipe group 4G, and in compliance with each old pipe arrangement of this pipe group 4G, the pipe group 5G is pushed from the tail by an advancing means such as a impact type propelling machine to cause advancing while insertion is made into the group 4G embedded position. Thereby the new pipes 5 are put on the old 4, and the pipe group 4G and surrounding soil are enwrapped with all pipe group 5G. If the enwrapped pipes 4 and soil are taken out to one side pit etc. after laying of subsequent pipes 5 is completed in this manner, removal can be done without leaving any bit underground. As a result, the pipe group 5G can be embedded in lieu of the pipe group 4G smoothly in the embedded position of pipe group 4G.</p> |
