Study on the influence of resin loss of the borehole on the anchoring performance in the soft and broken surrounding rock
Resin cartridge is the main adhesive between the bolt and surrounding rock.Fractures in the borehole wall of soft and broken surrounding rock may cause resin loss and af-fect anchoring performance.Therefore,a resin loss visualization experiment based on a 3D printed high transmittance borehole fractured model was conducted,and the influence of resin loss on anchoring performance was analyzed through theoretical analysis,numerical simulation,and laboratory experiments.The results show that in the process of bolt rotates and passes through the resin cartridge,the resin and curing agent will flow rapidly to the frac-ture of the borehole wall under the action of the motion of the bolt,and a solidification struc-ture will be formed inside the fracture.So that the anchoring length is shortened,and the a-mount of resin loss is positively correlated with the fracture aperture and the number of frac-tures.The grouting reinforcement of soft and broken surrounding rock,increasing the number of resin cartridges,and borehole reaming technology can weaken the influence of resin loss.A formula for calculating the length of resin cartridges based on resin loss is proposed.The paper can provide a certain theoretical reference for the research on the control and anchoring quality improvement of soft and broken surrounding rocks.
roof boltingsoft and broken surrounding rockfractures of the borehole wallresin lossanchoring performance
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