摘要 |
<p>PURPOSE:To make it possible to replace piping without excavating the surface soil of buried spots by outer fitting and inserting a large sheath-like pipe with a minor diameter larger than an outer diameter of an old pipe in the old pipe underground and inserting and laying out a new pipe while pushing out the large sheath-like pipe and the old pipe. CONSTITUTION:A large sheath-like pipe 4 with a minor diameter larger than an outer diameter of an old pipe 3 is successively connected to outer-fit and insertion all the old pipe 3 underground 2 from one pit, and the soil around the old pipe 3 is also involved into the large sheath-like pipe 4 together with the old pipe 3. After that, a new pipe 10 is inserted and laid out into a clearance eliminated by the large sheath-like pipe 4 while pushing out the large sheath-like pipe 4 and the rear end of the old pipe 3 from one pit. The large sheath-like pipe 4, the old pipe 3 and the excavated soil are collected by the other pit, and as the result, the cold pipe 3 is completely replaced by the new pipe 10 without leaving the old pipe 3 underground 2.</p> |