亿欣煤矿沿空切顶留巷围岩变形特征及控制技术

Deformation Characteristics and Control Technologies of Retaining Roadway Surrounding Rock in the Roof Cutting Along Goaf of Yixin Coal Mine

为优化矿山压力显现强度与煤炭资源回收效率,以亿欣煤矿XV1306试验工作面为例,采用数值模拟与工程实测方法开展无煤柱自成巷切顶应用技术。运用Rocscience-phase2软件分析了未切顶采场与切顶采场的覆岩运移特征,设计应用2种预裂爆破切缝参数与恒阻大变形锚索,同时对采空区后方实施二级预裂爆破。根据工作面推进位置设计3种支护形式,包括单体液压支柱支护、木垛支护、挡矸支护。结果表明:切顶方式下的覆岩应力为非对称分布,位移矢量仅在采空区内发育,地表的下沉量更小。配合临时支护与挡矸支护可有效控制围岩变形,顶底板最大移进量为324 mm,平均下沉量为245 mm。巷帮无明显碎胀与片帮,验证了无煤柱沿空留巷技术取得了较好的工程实践效果。

In order to optimize the manifestation strength of mine pressure and the efficiency of coal resource recovery,taking the XV1306 test working face of Yixin Coal Mine as an example,numerical simulation and engineering measurement methods are used to carry out the application technology of roof cutting in the self-forming roadway without coal pillars.The Rocscience-phase2 software is used to analyze the overlying rock transport characteristics of roof uncutting stopes and roof cutting stopes.Two types of pre-splitting blasting joint-cutting parameters and constant resistance large deformation anchor cables are designed and applied,and a two-stage pre-splitting blasting is implemented behind the goaf.Design three support forms according to the advancing position of the working face,including single hydraulic prop support,wooden pile support,and gangue blocking support.The results indicate that the overlying rock stress under the roof cutting method is asymmetric distribution,and the displacement vector only develops in the goaf,resulting in smaller surface subsidence amount.Combined with temporary support and gangue retaining support,the deformation of surrounding rock can be effectively controlled.The maximum displacement amount of the top and bottom plates is 324 mm,and the average subsidence amount is 245 mm.There is no obvious broken expand or wall caving of the roadway side,which verifies that the technology of retaining the roadway along the goaf without coal pillars achieves good engineering practice effects.