特厚煤层大采高综放工作面煤壁片帮机制分析

针对特厚煤层大采高工作面，将超前支承压力作用的煤体分为破裂区、塑性区和弹性区。考虑支架护帮阻力等因素，建立了支承压力作用的煤体变形破坏及煤壁片帮分析力学模型。通过摩尔-库仑准则和非关联弹塑性分析，推导出了煤壁水平位移量及破裂区和塑性区半径解析表达式，分析了影响煤壁片帮的主要因素。理论结果与现场实测结果误差仅为15.6%，验证了模型的正确性。研究表明，随支承压力集中系数的增大、机采高度的增加以及支架护帮阻力的减小，煤壁水平位移量明显增大，煤壁片帮程度严重。工程实践表明，提高支架工作阻力，减缓煤壁处压力，控制合理采高以及增大支架护帮阻力，可有效缓解大采高综放工作面煤壁片帮程度。

Analysis of rib spalling mechanism of fully-mechanized top-coal caving face with great mining height in extra-thick coal seam

Aiming at fully-mechanized top-coal caving face with great mining height in extra-thick coal seam, the coal mass affected by abutment pressure is divided into three zones, the fracture zone, the plastic zone and the elastic zone. A mechanical model of rib spalling affected by abutment pressure is established. With Mohr-Coulomb yield criterion and non-associated elastoplastic analysis, analytical expressions of coal wall horizontal displacement and the fracture zone and the plastic zone radii, are obtained by considering the hydraulic support protecting unit strength. At the same time, the main factors of rib spalling are analyzed. The model is demonstrated by comparing the theoretical results with the results of field measurement, the error is only 15.6%. The results show that with the increasing of abutment pressure concentration factor and cutting height and the decreasing of hydraulic support protecting unit strength, the horizontal displacement of coal wall increases and the extent of rib spalling is worse. Some measures, such as improving support resistance, reducing the pressure of coal wall, controlling the cutting height and increasing the protecting unit strength, are adopted to decrease the rib spalling.