Experimental Study of Stirring and Resin-Blocking Devices for Improving the Performance of Resin-Anchored Cable Bolts

Resin anchoring promotes the development of high-strength cable bolts for underground rock support. However, the resin anchoring the cable bolt must be very effective in soft rock. Using conventional anchoring methods, the anchoring force provided by cable bolts in soft rock is low, and achieving high-strength support is difficult. Aiming to address these problems, this study developed a method to stir the resin more completely and thereby improve the uniformity of the resin and increase its density in the anchoring area. The problem was investigated using theoretical analysis, numerical simulations, and laboratory and field tests. A method for improving the cable bolt anchoring quality is proposed and stirring and blocking devices (SBDs) for resin-anchored rock cable bolts are developed. The stirring device has three stirring blades on its top and the blocking device’s diameter is slightly smaller than the diameter of the borehole. Both devices have protruding left-handed threads on their surfaces. The mechanisms for improving cable bolt anchoring quality are demonstrated. The main conclusions drawn from this study are that the devices can effectively improve resin uniformity and increase the density of resin in the anchoring area. This improves the quality of the anchorage and thus enhances mine safety. The field test showed that compared with the anchoring force of conventional cable bolts, the anchoring force provided by cable bolts using the SBDs were increased by more than 30%. The SBDs are easy to install and have practical significance for improving cable bolt anchoring force.