大采高孤岛工作面片帮原因及控制技术研究

摘要

针对大采高孤岛工作面易发生片帮冒顶的难题,采用理论分析、数值模拟和现场实践的方法,对大采高孤岛工作面片帮冒顶原因及控制技术进行研究.研究结果表明:大采高工作面片帮冒顶不仅归因于围岩应力大、自由空间大、煤体裂隙发育程度高等自然因素,还受支架初撑力低、支护不及时等工程因素的影响.首次提出采用“棕绳+注浆”全长锚固技术相结合的综合控制技术,煤体与棕绳胶结为一体,显著增加了煤体的自承能力,增强了煤体的抗剪强度和拉伸力,且其应用成本明显低于传统的锚杆或锚索技术.通过数值模拟分析验证了该技术的控制效果,并在现场得到了成功应用,有效控制了煤壁片帮冒顶的发生,为类似大采高工作面煤壁片帮冒顶的防治提供了经验.%According to the spalling and roof falling easily occurred in the high cutting island coal mining face,the theoretical analysis,numerical simulation and site practice methods were applied to the study on the spalling and roof falling causes and control technology for the high cutting island coal mining face.The study results showed that the spalling and roof falling of the high cutting coal mining face were not only due to the high stress surrounding rock,large free space,high developed cracks of the seam and other natural factors,but also were influenced by the low initial support force of the powered support,untimely support and other engineering factors.A "palm rope+grouting" full length anchoring technology combined with the comprehensive control technology was firstly provided.The technology could make the coal seam and the palm rope bound as one body,could obviously improve the self bearing capacity of the coal seam and could enhance the shearing strength and tensile strength of the coal seam.And the application cost would be obviously lower than the conventional bolt and anchor technology.The numerical simulation analysis was verified the control effect of the technology.The technology was successfully applied to the mine site,could effectively control the spalling and roof falling occurred in the coal wall and could provide the experiences to prevent and control the spalling and roof falling of the coal wall in the similar high cutting coal mining face.