中厚煤层沿空留巷端头顶板断裂位置及巷旁支护强度研究

Study on the fracture position of end roof and the support strength of roadway side in gob-side entry retaining in medium-thick coal seam

针对沿空留巷端头顶板断裂位置不可见、很大程度影响巷旁支护强度计算的问题,围绕浅埋深中厚煤层工作面端头垮落特征和来压规律,采用理论分析与现场实测相结合的研究方法确定顶板断裂位置,并得出巷旁支护载荷及其强度;研究结果表明:通过“O X”理论,计算得出破断位置在实体煤柱侧2.4 m,实测破断位置在实体煤柱侧2~3 m之间;根据理论计算墩柱载荷为7473 kN;现场实测墩柱受力出现“增减增”3个阶段,最大载荷超过8500 kN。

The uncertain roof fracture position at the end of the gob-side entry retaining greatly affects the calculation of support strength of the roadway side.In view of the problem,according to the roof caving characteristics and pressure law of the end of the working face in the shallow-buried and medium-thick coal seam,the roof fracture position was determined by combination methods of theoretical analysis and field measurement,and the support load and strength of the roadway side were obtained.The research results showed that the breaking position was calculated as 2.4 m from the side of the solid coal pillar through the"O X"theory,while the field measured breaking position was between 2-3 m from the side of solid coal pillar;the theoretically calculated pier column load was 7473 kN,while the stress of the pier column measured on site showed three stages of increase,decrease and increase,and the maximum load exceeded 8500 kN.