沿空留巷两回采巷道分区域围岩控制技术研究

Regional surrounding rock control of gob-side entry retaining with two parallel mining entries

以神东煤炭集团锦界煤矿31116工作面两回采巷道为研究对象,提出了沿空留巷双巷综合支护技术思路:基于工作面的地质条件对工作面上方的关键层顶板进行分析确定,该工作面机尾压力较大,机尾采空区悬顶长度较大,悬顶长度最长时可达40m以上,宽度2m左右,机尾压力一直紧随工作面。结果表明:工作面上方存在三组关键层,其中J4岩层粉砂岩、J6粉砂岩层为亚关键层;J12岩层粗粒砂岩为主关键层;对工作面煤层以及顶底板进行参数测试,提供基本的力学数据;对空巷进行锚杆(索)支护模拟,模拟工作面回采期间,锚杆的受力状态以及围岩的变形效果;工作面推进过程中,对两回采巷道进行矿压规律的实时监测,对试验结果进行分析,验证机尾沿空留巷两回采巷道支护设计思路的可行性。现场实测结果表明:机尾围岩分区域综合控制技术可有效提高围岩得完整性。可以为类似沿空留巷条件下回采工作面支护方式的确定提供参考依据,利于沿空煤矿无煤柱开采的成熟应用。

Taking the two mining roadways in the 31116 working face of Jinjie Coal Mine of Shendong Coal Group as the research object,the technical idea of comprehensive support of double roadways with gob side entry is put forward:based on the geological conditions of the working face,the roof of the key layer above the working face is analyzed and determined.The working face has a large tail pressure,and the length of the suspended roof in the gob area at the tail is large.The longest length of the suspended roof can reach more than 40m,and the width is about 2m.The tail pressure has always followed the working face.The results show that there are three groups of key layers above the working face,among which J4 siltstone and J6 siltstone are sub key layers;J12 coarse sandstone is the main key layer;Test the parameters of coal seams and roof and floor of the working face to provide basic mechanical data;Simulate the bolt(cable)support in the goaf to simulate the stress state of the bolt and the deformation effect of the surrounding rock during the mining of the working face;In the process of advancing the working face,the real-time monitoring of the ground pressure law of the two mining roadways was carried out,and the test results were analyzed to verify the feasibility of the support design idea of the two mining roadways with gob side entry at the tail of the machine.The field measurement results show that the comprehensive control technology of the surrounding rock area in the tail of the turbine can effectively improve the integrity of the surrounding rock.It can provide a reference for the determination of the support mode of the working face under the similar conditions of gob side entry retaining,and is conducive to the mature application of pillar free mining in gob side coal mines.