Reaming Anchorage for Cable Bolts in Weak Rocks: Experimental and Numerical Investigations

To improve the anchoring force and quality of cable bolts in soft surrounding rock, we first conducted a theoretical analysis, which showed that irregular reaming enhances the interface forces between resin and surrounding rock, preventing failures in cable bolt anchoring. Conventional anchoring often suffers from low interface force, leading to debonding. Irregular reaming, however, increases this force, thus improving anchoring efficiency. Laboratory experiments confirmed these findings, showing that flexible reaming tools improved reaming quality and increased the peak pullout force of anchors compared to conventional methods. Numerical simulations further validated these results, revealing that irregular reaming increases interface forces. The simulations also emphasized that inadequate resin filling negatively affects anchoring performance. To address this, we developed an anchoring synergy device and a method to ensure effective anchoring at the bottom of the hole during reaming. Field tests demonstrated that irregular reaming significantly enhanced the anchoring force of cable bolts in weak surrounding rock, confirming the success of the approach in both laboratory and actual conditions.