大断面煤巷围岩支护技术

Surrounding Rock Support Technology of Large Section Coal Roadway

大断面巷道跨度大,尤其在厚煤层中掘进的大断面巷道容易出现顶板大量弯曲下沉及破碎,给巷道的支护问题带来了极大的挑战。为解决这一难题,采用力学分析、数值模拟的方法分析了大断面巷道顶板弯曲下沉的原因,并对不同巷道断面的应力及塑性区分布规律进行模拟,最终提出了支护方案。研究表明:对于大断面巷道最大弯曲下沉量应在顶板中点,随着巷道断面的增大,围岩塑性区域面积随之增大,顶板垂直应力逐渐减小,自承能力变差;顶板布置合理的高预应力锚索能有效地控制顶板离层,防治顶板大面积冒顶。在顶板设置对称分布的3根高预应力锚索后,顶板低应力区域明显减小,垂直位移减小,能够有效控制大断面巷道顶板冒落。

The span of large section roadway is large,especially the large section roadway excavated in thick coal seam is prone to a large number of bending,sinking and breaking of roof,which brings great challenges to the support of roadway.In order to solve this problem,use the methods of mechanical analysis and numerical simulation to analyze the reasons for the bending and subsidence of the roof of large section roadway,simulates the distribution law of stress and plastic zone of different roadway sections,and finally puts forward the support scheme.The research shows that the maximum bending subsidence of large section roadway should be at the midpoint of roof.With the increase of roadway section,the plastic area of surrounding rock increases,the vertical stress of roof decreases gradually,and the worse the self-supporting capacity is;the high prestressed anchor cable with reasonable roof layout can effectively control the roof separation and prevent large-area roof fall.After three symmetrically distributed high prestressed anchor cables are set in the roof,the low stress area of the roof is significantly reduced and the vertical displacement is reduced,which can effectively control the roof caving of large section roadway.