Study on the vibration response characteristics of broken roof rock in coal roadway

Background: Aiming at the challenges in control and perdition of roof strata which caused by the complexity of coal mine roof, the force and vibration characteristics of drill bit have been analyzed considering the coupling vibration between drill bit and coal rock, and the characteristics of coupled vibration have been studied under the condition of different rock hardness. Methods: The least-square method has been used to fit the vibration curve, besides, the trend term has been eliminated, and smooth treatment has been processed on the curve as well. Results: The study shows that the transverse vibration radius of the drilling mechanism increases as the coal rock hardness amplifies under the same experiment condition, and for same type rock, the horizontal vibrating decreases with the increase of fracturing intensity. Conclusion: The result shows that in anchor hole of coal roadway, the broken zone can be judged, and the degree of rock failure hazard can be predicted. Besides, the position and thickness of the stable rock in the anchor hole can also be judged, and technical support for roof support design can be provided. © Shuying Guo.