小煤柱沿空掘巷围岩变形控制机理研究

Research on Deformation Controlling Mechanism of the Narrow Pillar of Roadway Driving Along Next Goaf

针对沿空掘巷围岩的力学环境和支护特点,在分析巷道上覆岩层结构和巷道围岩结构稳定性的基础上,建立影响巷道围岩稳定性的各因素间相互关系的沿空掘巷围岩结构力学模型,通过对方程求解和规律分析,揭示了综放沿空掘巷围岩变形控制机理.研究结果表明,在小煤柱两侧分阶段注浆加固,形成由小煤柱、顶煤、顶板构成的超静定悬臂梁结构,可以促使顶板断裂线的位置从实体煤侧向邻近工作面的采空区侧移动,减小煤柱载荷,从而达到减小巷道变形、增强巷道围岩稳定性的目的;加固后的煤柱强度为原来的4倍时最佳.加固参数应用于实践,工业性试验效果显著,巷道围岩变形得到明显控制.

Aiming at the problems of underground stress conditions and supporting characteristics of roadway driving along goaf,we build a mechanical model containing factors that affect the stability of surrounding rock of driven roadway along goaf on the basis of analyzing the strata structure above surrounding roadway and the stability of roadway surrounding rock.The model reveals the controlling mechanism for mechanical deformation of narrow pillars.Results show that a cantilever structure composed of top coal and roof can be formed by grouting into the two sides of a narrow pillar,which can make brakeage position move from the coal seam to the goaf.And then,the load on narrow pillar is reduced and the deformation of roadway decreases,showing that the stability of surrounding rock is enhanced.According to the calculation result,the optimal reinforced strength on narrow pillar is 4 times greater than that of the original one.Industrial tests show that the deformation of roadway surrounding rock decreases remarkably by using the reinforcement parameters obtained from the analytical model in this paper.