基于切顶成巷的巷道顶板危险性分区试验研究

Experimental Research on Dangerous Zoning of Roadway Roof Based on Cutting Roof

为了能够在留巷前对预留巷道顶板进行准确的危险性评估,采用理论分析、现场试验等方法对预留巷道围岩危险性评估方法开展研究.建立巷道围岩危险性分区评估模型,并应用评估模型对禾草沟二号煤矿1105回风顺槽巷道围岩进行危险性评估,根据评估结果将巷道划分为危险区、较危险区、相对稳定区,并提出针对危险区、较危险区的补强方案.结果表明:虽然危险区与较危险区顶板及两帮变形得到了有效控制,然而危险区巷道顶板最大下沉量为210 mm,比相对稳定区、较危险区分别增大70 mm和25 mm,沿空留巷前预留巷道的补强支护能够有效控制沿空巷道围岩稳定性,但留巷前巷道顶板的弱化难以通过补强支护完全消除,锚杆(索)补强支护对成巷后顶板完整性的提升是有限的,后期应考虑局部注浆等措施进行加强.

In order to make an accurate risk assessment of the roof of the reserved roadway before it leaves the roadway,a theoretical analysis,field tests and other methods were used to conduct research on the risk assessment method of the surrounding rock of the reserved roadway.The risk assessment model of the surrounding rock of the roadway was established to evaluate the risk of the surrounding rock of the 1105 return airway tunnel in Hecaogou No.2 Coal Mine.Based on the evaluation results,the roadway was divided into dangerous areas,more dangerous areas,and relatively stable areas,and a reinforcement plan for dangerous areas and more dangerous areas was proposed.The results show that although the deformation of the roof and two sides of the dangerous zone and the more dangerous zone are effectively controlled,the maximum subsidence of the roof of the roadway in the dangerous zone is 210 mm,which is 70 mm and 25 mm larger than that of the relatively stable zone and the more dangerous zone respectively.The reinforcement support of the reserved roadway before the gob-side entry retaining can effectively stabilize the surrounding rock of the roadway along the goof,but the weakening of the roof of the roadway before the reserved roadway is difficult to be completely eliminated by the reinforcement support.Bolt(cable)reinforcement support has limited the improvement of the roof integrity after the roadway is formed,so measures such as local grouting should be considered in the later stage.