切顶参数对沿空留巷效果分析研究

Analysis and Study on the Effect of Roof Cutting Parameters on Retaining Roadway Along Goaf

为解决某矿沿空留巷围岩变形严重的问题,利用数值模拟软件对切顶卸压参数进行研究发现:切顶高度越大,巷道顶板垂直应力、位移越小,切顶7 m和切顶8 m效果影响差距较小;在切顶角度为0°、15°、25°条件下内部垂直应力最大值分别为12.1 MPa、10.9 MPa、12.0 MPa,顶板垂直位移最大值分别为250 mm、300 mm、500 mm;经综合比较,选定合理的切顶高度为7 m,切顶角度为15°。对合理参数下围岩变形进行监测,发现经过切顶卸压后巷道的围岩变形量得到了有效的控制,巷道顶板、底板的变形量最大值为50 mm和52 mm,巷道矸石侧移近量最大值为27 mm,煤帮侧的移近量最大值为60 mm,切顶卸压沿空留巷较为成功。

In order to solve the problem of serious deformation of surrounding rock of retaining roadway along goaf,this paper uses numerical simulation software to study the pressure relief parameters of roof cutting.It is found that the larger the height of roof cutting is,the smaller the vertical stress and displacement of roadway roof is,and the difference between the effects of 7 m and 8 m roof cutting is small.When the cutting angle is 0°,15°and 25°,the maximum internal vertical stress is 12.1 MPa,10.9 MPa and 12.0 MPa respectively.The maximum vertical displacement of the roof is 250 mm,300 mm and 500 mm respectively,so the reasonable cutting height is 7 m and the reasonable cutting angle is 15°through comprehensive comparison.By monitoring the surrounding rock deformation under reasonable parameters,it is found that after roof cutting and pressure relief,the surrounding rock deformation of the roadway has been effectively controlled.The maximum deformation of the roadway roof and floor is 50 mm and 52 mm,the maximum displacement of the roadway gangue is 27 mm,and the maximum displacement of the coal side is 60 mm.The roadway retention is relatively successful.