坚硬顶板矸石充填采场支承压力分布特征

Abutment Pressure Distribution Characteristics in Gangue Filling Stope With Hard Roof

某矿4916工作面开采9#煤,由于煤层上部直接覆盖厚24.5 m的火成岩,为避免采动造成的冲击地压危害,利用矸石充填工艺进行回采,为得到充填效果,利用数值模拟和现场实测手段对充填后采动应力场进行了研究。结果表明受相邻工作面的影响,煤壁前方支承压力场不是沿工作面中部对称分布,工作面上端头支承压力峰值和影响范围最大,中部次之,下端头最小,充填后峰值位置距煤壁很近,仅为6 m,最大值可达15 MPa,即工作面仍有动压冲击的危险,因此实际回采过程中配合使用强制放顶措施,实现了4916工作面的安全回采。

The 9# coal is mined at 4916 working face of a coal mine. Due to the 24.5 m thick igneous rock lying above the coal seam, the gangue filling process is applied to avoid the percussive dynamic pressure triggered by the coal excavation. In addition, the mining stress filed after filling is studied by the method of numerical simulation and field measurement for obtaining the filling results. The re- suits indicate that the abutment pressure field in front of the coal wall is not distributed symmetrically along the middle of the working face affected by the adjacent working face. To be specific, the peak value of abutment pressure and its scope of the upper termination occupy the first place ; the middle part comes second and those of the lower termination are minimal. The peak point is quite closed to the coal wall with the distance being only 6 m and the value researches 1.5 MPa. In other words, the working face is still in danger of percussive dynamic pressure. Therefore, forced caving is applied in practical mining process to achieve the safety at 4916 working face.