Meitan kexue jishu (Jan 2024)
Design principle and engineering practice of rock bolting to prevent coal bump from rib coal massive slippage
Abstract
Rock burst is one of the disasters that seriously affect the safe and effective mining of coal in mine mining. It is of great significance and value to study the principle and technology of bolt anti-impact support to prevent and control the rock burst disaster in roadway. Through the summary and analysis of the geological conditions and failure characteristics of the rock burst of the whole coal body in the roadway, it is considered that the hard roof and hard coal seam are the important geological characteristics of this type of rock burst, and the overall slippage of the coal body in the roadway is the main impact failure characteristics. On this basis, taking the sliding coal body of roadway side as the research object, the mechanical model of roof-roadway-floor composite structure is established, and the limit equilibrium equation of horizontal sliding of roadway side coal body is established, and each parameter is analyzed. The results show that due to the rebound of the roof, the vertical pressure of the roadway side coal body is reduced, and the roadway side coal body is pushed into the roadway by the tectonic stress to cause rock burst. Based on the occurrence mechanism model, it is considered that the current bolt support design system has some shortcomings in preventing and controlling the rock burst of the coal body in the roadway. Based on its occurrence and failure characteristics, the design principle of bolt anti-impact support for the overall slippage type rock burst of the coal body in the roadway is established, that is, the anchoring ends of the roof and bottom bolts are respectively penetrated into the stable roof and floor, and the long anchor cable is used to replace the middle side bolt to provide the anti-impact effect of bolt support. Based on the newly established design method of bolt anti-scour support, taking the anti-scour support of 7305 working face of Kongzhuang Coal Mine in Datun Mining Area as the engineering background, the anti-scour design is adopted in the bolt support of roadway side in the wide coal pillar section. The roof and bottom bolts and reinforcing anchor cables are anchored inside the roof and floor, which can effectively absorb the sliding kinetic energy of the coal body and improve the safety.
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