*Article* **Factors Influencing the Load-Bearing Capacity of Rock as Base Material for Post-Installed Anchors**

**Stefan Lamplmair 1, Oliver Zeman 2,\* and Klaus Voit <sup>1</sup>**


**Abstract:** In the case of fastenings on rock, as a result of the variability, it is quite difficult to make a preliminary assessment of the load-bearing capacity of rock as a base material. This paper therefore investigates which rock parameters next to an anchor position have an influence on the load-bearing capacity. For this purpose, tests are carried out on post-installed anchors in different lithologies in eastern Austria. It can be shown that the joint weathering has an influence on the load-bearing capacity of post-installed anchors and conclusions can be made about joint weathering by means of rebound hammer. Rebound values can therefore also be used to draw conclusions about the rock quality as a base material for post-installed anchors. Nevertheless, a combined optical assessment of the base material is recommended as an adequate method.

**Keywords:** base material; rock; post-installed anchors; adhesive anchor; mechanical anchor; loadbearing capacity; GSI; RMR; rebound value; rebound hammer
