| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a laying method of a chilled gas pipe line in which bending stress produced in a boundary between permafrost and non-permafrost can be suppressed in a chilled gas pipeline laid in a permafrost area. <P>SOLUTION: The laying method contains a buffer section (a back-filling layer 15) focusing attention on the characteristic length (1/λ). The shape of the buffer section has the maximum diameter of the frost valve on a permafrost side and a pipe laying standard cross section on a non-permafrost side. The buffer section substitutes nonfreezing materials (for instance, gravel, sand, wood chips, clinker ash, waste tire chips, or the like). In the buffer section, the depth of back filling using nonfreezing materials is reduced from the starting point B toward the end point C. The buffer section is formed in a triangular or square pyramid shape. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
