Abstract:
To address the issues in resin anchoring for cable bolts with reaming in soft rock roadways, such as insufficient stirring of resin anchoring agent, inadequate filling in reamed areas, eccentricity of cable bolts, and damage to hole walls, a resin anchoring enhancement technology based on the Multi-segment Reaming Anchoring Enhancement (MRAE) component is proposed. Through theoretical analysis, the mechanisms of MRAE are revealed, including the "graded crushing-gradient stirring", the synergistic flow control of "ascending guidance-sealing", and the "centralized limiting-radial support". These mechanisms clarify how MRAE improves the stirring effect of resin anchoring agent, the strength of the anchor solid, the pull-out resistance, and the centering performance of the cable bolt. Numerical simulations are used to compare and analyze the characteristics of the stirring flow field of resin anchoring agent between MRAE and ordinary cable bolts, verifying that MRAE enhances the migration speed and diffusion range of resin. Laboratory tests are conducted to study the influence of MRAE on the drilling thrust, torque, and pull-out force of cable bolts. The results show that the average peak pull-out force of the enhanced anchoring group (36.5 kN) is 2.5 times that of the ordinary anchoring group (14.9 kN), and the centering degree is significantly improved. Field tests further verify the effectiveness of this technology. In soft rock roadways, both the pull-out force and pre-tightening force of the enhanced anchoring cable bolts meet the design values. The roof separation displacement is reduced by 1.52 times compared with ordinary anchoring. Even under non-reaming conditions, its anchoring force still meets engineering requirements. The research results provide a theoretical basis and technical support for improving the anchoring quality of cable bolts in soft rock roadways.