工作面坚硬顶板破断特征与覆岩运移规律

Fracture Characteristics of Hard Roof and Overlying Rock Movement in Working Face

针对坚硬顶板综放工作面顶板破断特征与覆岩运移规律不清,在实际生产中严重影响工作面安全生产这一问题;以某矿8201工作面为工程背景,采用理论分析、数值模拟以及现场实测的方法对坚硬顶板综放工作面的顶板破断特征以及覆岩运移规律进行研究分析。研究结果表明:对顶板煌斑岩进行岩石力学实验得知煌斑岩在节理面单轴抗压强度为45 MPa左右,无节理为90.99MPa、单轴抗拉强度7.3～9.4 MPa;通过建立深梁结构破断过程中顶板受力模型,得到基本顶初次来压步距为47.57 m;数值模拟得到8201基本顶的初次来压步距约为45 m,周期来压的距离为20 m左右。在现场实测中基本顶初次来压平均46 m,周期来压步距为18.7～20.8 m,来压影响范围1.7～5.6 m。现场实测与理论分析所得结果和数值模拟所得结果相差不大。

In view of the problem that the characteristics of roof breaking and the law of overburden rock movement in hard roof fully mechanized caving face are not clear in actual production, the safety of working face is seriously affected. In this paper, based on the engineering background of 8201 working face in a certain mine, the characteristics of roof breaking and the law of overburden rock movement in fully mechanized top -coal caving face with hard roof are studied and analyzed by theoretical analysis, numerical simulation and field measurement. The results show that the uniaxial compressive strength of lamprophyre is about 45 MPa, the non-joint is 90.99 MPa and the uniaxial tensile strength is 7.3 MPa to 9.4 MPa. In the process of fracture, the stress model of roof is obtained, and the first step distance of basic top is 47.57 m, and the first step distance of 8201 basic roof is about 45 m and the distance of periodic pressure is about 20 m by numerical simulation. The average initial top pressure is 46 m, the interval of periodic pressure is 18.7 m to 20.8 m, and the in fluence range is 1.7 m to 5.6 m. There is little difference between the results of field measurement and theoretical analysis and the results of numerical simulation.