| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To perform towing and jacking of a newly laid pipe fitted to the rear of an underground supply pipe reasonably and protect the surface of the pipe with material for preventing damage of the surface, which is thin and hard and of high strength. <P>SOLUTION: In laying a newly laid pipe by towing and jacking method, according to this means, for reducing the damage of the pipe surface even if the newly laid pipe is passed under the ground, the newly laid pipe surface is protected using a protective member which is thin to be low-resistance to earth, formed of material such as metal, resin or chemical fiber and hard and of high strength, to perform towing and jacking, and the protective member is left as it is still installed on the newly laid pipe or removed by pulling after the pipe is laid. According to another means, a temporary pipe is installed in the rear of the existing pipe, the temporary pipe having a larger bore diameter than a newly laid pipe is once passed to reduce the resistance of earth applied in leading in the newly laid pipe. According to still another means, a temporary pipe is installed for the purpose of towing a newly laid pipe having a larger bore diameter than the existing pipe, and the newly laid pipe is connected to a thick rope in the temporary pipe and the newly laid pipe with high towing resistance is towed without breaking the rope to perform replacement of the laid pipe. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
