针对烧变岩巷道围岩力学性能显著偏低的问题, 以王才伙盘煤矿烧变岩区3202工作面回风巷为研究对象, 利用Hoek-Brown修正准则求解了巷道围岩各分区应力及塑性区半径解析表达式, 揭示了围岩稳定性的关键影响因素; 明确了烧变岩区围岩控制策略, 阐述了巷道浅部注浆和主、被动支护控制原理; 对无支护、锚杆(索)支护以及浅部注浆+主被动联合支护等3种支护方式的围岩应力分布、变形特征、裂隙发育以及支护系统受力特征进行了模拟。研究结果表明: 巷道松动圈主要与地质强度指标、岩体破碎度等因素密切相关; 综合理论计算和现场实测结果, 得到松动范围为4.2 m; 3种支护方式拉应力峰值分别为1.14, 0.85和0.81 MPa; 偏应力峰值距巷道表面的最大距离分别为2.59, 1.44和0.83 m; 顶板最大移近量分别收敛于350, 205和24 mm; 采用“注浆+锚杆(索)+金属架棚”支护形式, 可在围岩浅部形成稳定承载点, 实现有效支撑, 同时锚杆、锚索支护作用得到充分发挥。现场工程实践结果显示, 采用联合支护方式, 巷道顶板及两帮移近量均小于50 mm, 有效稳定了烧变岩区的巷道围岩。研究成果可为同类地质条件下的巷道围岩控制提供参考。

The significantly reduced mechanical properties of surrounding rock in burnt rock roadways caused by spontaneous coal seam combustion present substantial engineering challenges. This study investigates the 3202 return airway in the burnt rock zone of Wangcaihuopan Mine. Using the modified Hoek-Brown criterion, analytical expressions for the stress distribution and plastic zone radius in the surrounding rock were derived, revealing key factors affecting rock stability. A combined strategy involving shallow grouting and active-passive support is proposed for stabilizing the burnt rock roadway. Numerical simulations using UDEC were conducted to analyze stress distribution, deformation characteristics, crack development, and support system performance under three scenarios: unsupported, anchor (cable)-supported, and shallow grouting combined with active-passive support. The results indicate the loosened zone of the roadway is closely associated with geological strength index, rock fragmentation, and related factors. The calculated and measured loosened range is 4.2 m. Peak tensile stresses under the three support schemes were 1.14, 0.85, and 0.81 MPa, respectively, while peak deviatoric stress distances from the roadway surface were 2.59, 1.44, and 0.83 m. Maximum roof surface convergences were reduced from 350 mm (unsupported) to 205 mm (anchor-supported) and further to 24 mm (combined support). The combined grouting-anchor(cable)-metal frame support system effectively forms stable load-bearing points in the shallow surrounding rock, significantly enhancing support effectiveness. Field tests confirm that using this combined support technology limits the convergence of the roadway roof and sidewalls to less than 50 mm, ensuring stability in the burnt rock zone. These findings provide valuable guidance for surrounding rock control in similar geological conditions.