大埋深岩巷支护优化技术实践

Practice of support optimization technology for large buried deep rock roadway

城郊煤矿二水平西翼轨道大巷埋深800 m,沿二_(2)煤顶板穿层掘进,采用常规的锚网喷支护后,巷道变形严重,维修周期短,费用高。对顶底板围岩力学参数进行测试,结果表明,煤层顶板复合性质明显,抗压强度低且变化较大,岩体呈明显非均质性,且RQD分级属于“差”等级;围岩松动圈范围普遍在2.0 m以上,为大松动圈不稳定围岩,由此提出提高预紧力和协同支护的控制思路,优化了支护方案,现场应用效果良好。

The buried depth of the track roadway in the west wing of the second level of the Chengjiao coal mine is 800 m,and it is excavated along the roof of the second 2 coal seam,which is a cross-layer roadway.After using the conventional anchor cable spray support,the roadway deformation is serious,the maintenance period is short,and the cost is high.The mechanical parameters of the surrounding rock of the roof and floor are tested.The results show that the composite properties of the coal seam roof are obvious,the compressive strength is low with large change,the rock mass is obviously heterogeneous,and the RQD classification belongs to the'poor' level.The range of surrounding rock loose circle is generally above 2.0 m,which is unstable surrounding rock with large loose circle.Therefore,the control idea of improving pre-tightening force and collaborative support is put forward,and the support scheme is optimized.The field application has achieved good results.