| 摘要 |
<p>The present invention relates to a friction rock bolt the anchor portion of which is formed by one or several rods (1) of solid section and an expanding element (2) abutting parallel to these rods (1) for their pressing against a borehole (13) wall. Said expanding element (2) is formed for example by a thin-walled expansion tube (3) with distorted cross section in the form of a longitudinal groove intended for placing therein each rod (1).</p> |
