Synergistic Mechanism and Technology of Cable Bolt Resin Anchoring for Roadway Roofs with Weak Interlayers

The process of cable bolt anchoring the roof of a coal mine roadway involves the mixture of different types of resin cartridges. However, this procedure presently faces several shortcomings including insufficient cartridge breakage, non-ideal viscosity and annular thickness values of the anchoring body, short effective anchorage length, incomplete hole walls in the surrounding rock, the resin cartridges easily roll, bend, overlap, and pile up on the hole wall and do not properly react. This study presents a systematic analysis of the anchoring characteristics of roof cable bolts in a roadway with weak interlayers based on the research and development of synergistic components. The synergistic mechanism is identified. Numerical simulations are performed to demonstrate the dynamic flow field characteristics of the resin cartridge mixing, and laboratory tests are performed for comparison to determine a reasonable setting for the synergistic components. Field tests are conducted to comprehensively verify the working performance of the synergistic technology. The results show that the synergistic component can greatly improve the fluidity and uniformity of the resin cartridge reaction. The anchoring performance of the synergistic anchorage cable bolt used in the field is also significantly greater than that of ordinary anchoring cable bolts and higher than or equal to the engineering requirements. When an anchor hole is broken or collapses, the spacing of the synergistic components can be reasonably adjusted (i.e., by shortening the anchorage length) to allow the resin cartridge to evenly and densely fill the anchoring area, which greatly improves the anchoring system’s bearing capacity.