深井岩巷破坏机理与支护优化研究

岩巷的稳定性评价与支护设计对深井岩巷掘进和维护十分重要。为了开展深埋煤矿岩石巷道围岩稳定性分析和锚网支护参数优化分析,以文家坡煤矿深埋一号辅助运输大巷为工程背景,采用多种监测手段完成了岩巷变形特征的实测分析,然后运用数值模拟的方式从巷道围岩塑性区发展规律和围岩应力变化特性两方面分析了巷道围岩变形破坏机理,最后根据现场监测和模拟结果优化了该巷道的支护方案,并进行了模拟验证。结果表明:随着巷道不断地向前掘进,巷道两帮围岩塑性区厚度先增大直到逐渐稳定,自重引起的水平应力使巷帮向巷道内收敛,顶板产生剪切破坏,两帮产生劈裂破坏;原支护方案作用下巷道围岩变形量非常小,锚杆(索)支护方案过于保守。将帮部锚杆长度由2.7 m优化到2.3 m后,在其他支护参数保持不变的情况下支护可以满足巷道稳定性的要求。

Failure mechanism and support optimization of deep rock roadway

Stability evaluation and supporting design of rock roadway in deep mine is very important to excavate and maintenance for the roek roadway in deep mine, depended on the engineering background of the NO. 1 auxiliary main haulage roadway of Wenjiapo coal mine, variety means of monitoring method were used to complete the analysis of deformation characteristics of rock roadway in field. Then, by the using of numerical simulation, the deformation law of surrounding rock was analyzed from the two aspects of the development law of plastic zone and change characteristics of surrounding rock stress. According to the field monitoring and the simulation results, the support plan was optimized, and simulation was cartied out to verify it. The results showed that：with the continuous driving of roadway, the plastic zone thickness of roadway surrounding rock in two sides increased at first, and gradually became stabilized, the shear failure in roof and splitting failure at two ribs were produced by the horizon stress from self weight; the roadway surrounding rock deformation amount was very small under the original support scheme, the bolt （cable）support scheme is too conservative, the length of side bolt was optimized from 2.7 m to 2.3 m, the support of roadway can meet the requirements of stability in the condition of unchanged other supporting parameters.