| 摘要 |
<p>Charging Large Diameter Vertical Boreholes A method of charging upwardly extending, large diameter boreholes with cylindrical explosive cartridges is provided employing a longitudinally inflating flexible tube as the pushing mechanism. A fluid-impervious flexible tube is turned over or everted at one end and secured. A fluid, preferably air, at about 3 psi is passed into the tube causing the tube to elongate and the everted tube face to travel along the length of a borehole. An explosive cartridge mounted against the tube face is carried to a desired location in the borehole after which the tube is partly deflated and withdrawn from the borehole.</p> |
