| 摘要 |
<p>The invention relates to a yielding roof bolt with a bolt head (2) which can be secured in place at the bottom of the bolt borehole (1), an extensible bolt shank (5) which consists of a bundle of steel rods or steel wires (9), and a restrainable bolt plate (8) bearing against the mouth of the borehole. In order to design such a roof bolt in such a way that it can extend under uniformly high load-bearing capacity, the invention proposes that the steel rods or steel wires (9) be arranged in a twisted or interwoven manner in such a way that they draw closer to one another during tensile loading of the bolt shank (5) with elongation of the bolt shank, and that material which yields plastically under the action of pressure be arranged between the steel rods or steel wires (9). <IMAGE></p> |
