大倾角煤层回采巷道非对称锚网索支护与实践

Study on Asymmetrical Bolting Support of Retreating Entry in Large Dip Coal Seam and It's Practice

根据淮南矿区大倾角(25°～45°)煤层开采地质和技术条件,采用物理模拟综合分析了大倾角煤层回采巷道围岩结构特征及采用锚杆支护时的围岩变形、破坏、应力演化等力学特征,揭示了大倾角煤层回采巷道围岩力学特征非对称演化机理。研究表明,实体煤回采巷道应重点支护顶板和高帮,而留小煤柱回采巷道应重点支护顶板和低帮。基于巷道围岩力学特征的非对称性,提出并实施了大倾角煤层实体煤回采巷道和留小煤柱回采巷道的非对称锚网索支护方法。工程应用表明,非对称锚网索支护能适应大倾角煤层回采巷道围岩结构和力学特征,有效控制巷道围岩变形。

According to geological and technical conditions of large dip coal seams （LDCS） whose angle is from 25° to 45° in Huainan Coal Mine, a physical model was used to simulate configuration and mechanical characteristics of roadway with bolt supporting, such as patterns of deformation, displacement, failure, and mining-induced stress （MIS） of surrounding rock. It revealed the unsymmetrical mechanism of mechanical characteristics of surrounding rock of retreating entry in large dip coal seams. Study result shows that additional support needs to be implemented for different sections of roadway. The roof and upper-fib of solid roadway are the main supporting section but, the road- way of gob-side with small width pillar, the roof and lower-rib are the key sections. So considering the dissymmetrical strata behaviors and mechanical characteristics, the asymmetrical bolting support technique （ABST） was put forward and implemented. The engineering practice shows that ABST is suitable and reliable for controlling rock stability in LDCSs mining.