恒昇煤矿采场覆岩应力分布与导水裂隙带高度研究

Study on Stress Distribution of Overlying Strata and Height of Water Flowing Fractured Zone in Hengsheng Coal Mine

依据恒昇煤矿9301工作面水文地质资料,建立9301工作面采动覆岩数值计算模型,模拟分析工作面采场覆岩应力分布、破坏特征及导水裂隙带发育高度。并利用分布式光纤测试技术,在9301回采工作面上方布设分布式光纤,监测9301工作面回采过程中采场覆岩离层破坏区域应变数据,分析得出9301工作面采场覆岩变形、破坏特征及导水裂隙带发育高度。研究结果表明:9301工作面回采后,采空区上方出现应力降低区,呈"拱型"分布形态;沿工作面推进方向和倾斜方向,采场覆岩卸压拱基本呈对称分布形态。9301工作面覆岩冒落带高度与工作面推进距离关系不大,随工作面推进距离的增加而缓慢增加。导水裂隙带发育高度随着工作面推进距离的增加而快速增加,在工作面一次见方后,导水裂隙带发育高度趋于平缓,基本保持在一个稳定值。光纤应变分布与采场上覆岩层岩性具有很好的对应关系,光纤应变值在弹性模量较高岩层中相对较小,而在弹性模量相对较低岩层中则相对较大,证明煤矿回采过程中上方软弱岩层易发生变形破坏。通过数值计算及现场分布式光纤实测综合确定9301工作面冒落带发育高度为13.1~16.33 m,导水裂隙带发育高度为58~60.6 m。

Based on the hydrogeological data of 9301 working face in Hengsheng coal mine, the numerical calculation model of mining overburden in 9301 working face is established to simulate and analyze the stress distribution, failure characteristics and development height of water flowing fracture zone of overburden. By using distributed optical fiber testing technology, distributed optical fiber is laid above 9301 working face to monitor the strain data of overburden strata separation failure area in 9301 working face. The deformation and failure characteristics of overburden strata in 9301 working face and the development height of water flowing fracture zone are analyzed. The research results show that: after the 9301 working face is mined, the stress reduction area appears above the goaf, which is in the form of "arch" distribution;along the advancing direction and inclined direction of the working face, the pressure relief arch of the stope overburden is basically symmetrical distribution. The height of overburden caving zone of 9301 working face has little relationship with advancing distance of working face, and increases slowly with advancing distance of working face. The development height of the water flowing fractured zone increases rapidly with the increase of the advancing distance of the working face.After the first square of the working face, the development height of the water flowing fractured zone tends to be flat and basically remains at a stable value. The optical fiber strain distribution has a good corresponding relationship with the lithology of the overlying strata. The optical fiber strain value is relatively small in the strata with higher elastic modulus, but relatively large in the strata with lower elastic modulus, which proves that the upper weak strata are prone to deformation and damage in the process of coal mining. Through numerical calculation and field distributed optical fiber measurement,it is determined that the development height of caving zone in 9301 working face is between 13.1 and16.33 m, and the development height of water flowing fractured zone is between 58 and 60.6 m.