| 摘要 |
<p>A flexible multi-strand steel cable 22 of a preselected length is inserted in a bore hole 18 drilled in a rock formation 12 above an underground excavation. The cable 22 includes an anchor end portion 24 frictionally engaging the bore hole 18 and, also chemically bonded to it. The cable 22 extends out of the bore hole 18 and includes a drive end portion 26 that retains a bearing plate 102 engaging the rock surface 16. The drive end portion 26 includes a plug 50 comprising a pair of diametrically positioned jaw members 54, 56 which are urged into nonrotational gripping engagement with the steel cable by movement of the housing 82. End portions 68 of the jaw members 54, 56 extend out of the housing 82, and are engaged by a torque transmitting device (not shown) to transmit upward thrust and rotation through the jaw members 54, 56 to the cable 22 to place it in tension to reinforce the overlying strata of the rock formation. <IMAGE></p> |
