| 摘要 |
<p>PROBLEM TO BE SOLVED: To reasonably embed a gas pipe through which fuel gas having a pressure of about 1 to 10kg/cm<2> flows. SOLUTION: A gas pipe A is formed in such a way that an inner pipe 2 such as a steel pipe is fitted in an outer pipe such as a vinyl chloride pipe, a polyethylene pipe, a synthetic resin pipe or a steel pipe, and holding members are interposed between the outer and inner pipes so as to define a gap therebetween. The gap pipe A is caused to follow an excavator for excavating the natural ground or a guide machine B for compacting the natural ground so as to form a tunnel, and a base pusher C laid in a vertical shaft D applies a thrust force to the inner pipe 2 so as to advance the inner pipe 2 from the vertical shaft D to a destination vertical shaft E. Each time when a single gas pipe A is advanced, a new inner pipe 2 is welded and connected to the inner pipe 2 in thus advanced gas pipe A, and accordingly, the outer pipes 1 are made to abut against each other so as to repeat the advance of the outer pipes 1.</p> |
