| 摘要 |
<p>The invention provides that an underground through borehole (28) is formed with a reaming tool (24). It is filled with a viscous fluid and as soon as possible after being so filled, a flexible lining tube (32) is inserted into the borehole (28) to keep the surface from collapsing until a rigid service pipe (12) has been pulled or pushed into the borehole.</p> |
