松软厚煤层超高巷道围岩失稳因素分析与控制技术

Instability factor analysis and control technology of surrounding rock of soft and thick coal seam ultra-high roadway

安阳主焦煤矿2301综放工作面回风巷沿煤层顶板布置,但在回采过程中,存在上端头三角煤损失和巷道底板煤层无法回收问题。为此,提出了回风巷超前底煤回收工艺,但面临着超前超高回采巷道围岩控制问题。支承压力高、煤体软弱、巷道超高和超前架反复支撑等因素导致超高巷道变形严重;结合回收底煤工艺和巷道变形破坏特征,提出了主被动联合支护、强化巷帮支护的控制策略和强力锚网索+超前超高液压支架联合支护方法。采用离散元数值模拟方法,分析了不同支承压力下巷道围岩塑性区、位移和应力场分布特征,验证了支护方案的合理性。现场工业性试验表明,补打锚杆、强化超前支架护帮等措施,能够有效控制巷道片帮现象。采用超高巷道围岩控制方法可多回收煤炭资源2.44万t,直接经济效益2.19亿元,具有较强的技术经济前景。

The No.2301 fully-mechanized caving face of Anyang Main Coking Coal Mine is arranged along the roof of coal seam along the return airway,but in the process of mining,there are problems of triangular coal loss at the upper end and the coal seam of roadway floor cannot be recovered.For this reason,the advanced floor coal recovery process was proposed,but facing with the problem of surrounding rock control of the advanced ultra-high mining roadway.The factors such as high abutment stress,weak coal body,ultra-high roadway,and repeated support from advanced frames lead to severe deformation of ultra-high roadway.Based on the process of floor coal recovery and the deformation and failure characteristics of roadways,the control strategy of active and passive combined supporting,strengthening roadway wall supporting and the combined support method of strong anchor net cable and advanced ultra-high hydraulic support were put forward.The distribution characteristics of plastic zone,displacement and stress field of roadway surrounding rock under different abutment stress were analyzed by using discrete element numerical simulation method,and the rationality of supporting scheme was verified.On-site industrial experiments show that measures such as adding anchor rods and strengthening advanced support can effectively control the phenomenon of roadway rib spalling.The use of ultra-high roadway surrounding rock control method can recover 24400 tons of coal resources,with a direct economic benefit of 219 million yuan,and has strong technical and economic prospects.