Theoretical And Applicational Study Of Anchor Reinforced Arch In Roadway Surrounding Rock

With the development of bolting technology and reinforcement theory, the bolting hasbeen widely used in the coal mines, tunnels and other underground works. However, due tothe mechanism action of the surrounding rock bolt reinforcement is complex, the boltmechanism research is still in the exploratory stage and serious lag in practice. In this paper，the existing bolt supporting mechanism were analized and the theory of reinforcement archbeen depth studied. Then proposed the circular reinforced area of the single bolt’s mechanicalmodel basing on of the existing research conclusions.Through mechanical analysis, thereinforcement arch’s mechanical characteristics of the different forms in circular, arched andrectangular roadway have been studied. Finally, based on of engineering practice,by analyzingthe site monitoring data and proposing a support optimization scheme of the roadway.Through this study, obtained the following conclusions:1、The existing bolting theories are analyzed. Focus on the mechanism of reinforcementarch theory and analyze the extrusion reinforcement effect of bolts in surrounding rock.2、Analyzed the anchorage loading mechanism and mechanics of bolts on surroundingrock. Based on the existing reinforcement mechanical model of single bolt，proposed thecircular reinforcement area mechanics model. Analyzed the the stress distribution law inreinforcement area accordance with the theory of elasticity and derived the range of thereinforced area’s calculation formula combined with rock mechanics theory. Obtained therelationship between the reinforcement area, reinforcement load and the surrounding rock’sby parametric analysis, and derived calculation formula of the reinforced arch’s thicknessbetween bolt length and inter-row spacing based on the geometry relations.3、Study the arching load of bolts in forming the reinforcement arch in the roadway andobtain formula the arching load between bolt length, surrounding rock parameters and groundstress, then get the relationship curves of the arching load and bolt length under different conditions by parametric analysis. Analyze the failure modes, thickness and stability of thereinforced arch in circular, arched and rectangular roadway and obtain the reasonable designthickness of reinforced arch in the form of two roadway section.4、By analyzing the mine pressure monitoring data of the5thcoal central air returnroadway in He Cao Gou coal mine and optimizing the existing bolt support programs basingon the reinforced arch design theory in arched tunnel proposed in this paper. The numericalsimulation analyses have been done in this paper of the optimized support program and proveits reasonableness.