不稳定围岩条件下大断面硐室掘进和支护的技术探讨

The Research about the Tunneling and Supporting Technologies for the Chambers with Large Cross Section in the Condition of Unstable Rock Surrounding

神华蒙西棋盘井煤矿隶属于桌子山煤田棋盘井南部井田,9#煤层围岩的稳定类别在采动条件下为Ⅲ～Ⅳ类,井下大断面换装硐室的掘进和支护技术难度很大。针对这一情况,矿方与山西太原理工大学合作,通过进行岩性和地应力分析,运用采动模拟系统,提出了按台阶、阶段和块段分步掘进、支护和分次浇注的施工工序;确定了采用"锚杆+钢筋焊接网"作为基本支护方式,快速承载预应力锚索作为加强支护方式,并给出了合理的锚固参数,较好地控制了大断面硐室的不稳定围岩,工程质量达到优良。

Qi Panjing Coal Mine of Shenhua Mengxi Coal Chemical Co.,Ltd.locates at the southern mining area of Qi Panjing,Zhuo Zishan Coal Field.While mining,the stability level of surrounding rock in number 9 coal seam is between Ⅲ and Ⅳ which make it very difficult to tunnel and support the underground rehandling chambers with large cross section.To deal with this problem,the company cooperated with Shanxi Taiyuan University of Sci-ence and Technology.Through analyzing the lithological characters and geo stress and applying mining simulation system,they put forward a construc-tion process which is to excavate,support and grade casting by stages,period and segment.They also decided to use 'bolt plus steel welding net' as the basic supporting method and the fast-loading prestress cable as strengthen supporting method.They also figured out a reasonable anchoring parameter.Through all of these,they reached a better control on the unstable rock surrounded chambers with large cross section and achieved a good quality of the whole project.