• 中文核心期刊
  • 中国科技核心期刊
  • RCCSE中国核心学术期刊
  • Scopus, DOAJ, CA, AJ, JST收录期刊
高级检索

沿空煤巷过断层破碎带围岩控制技术研究

Study on surrounding rock control technology of gob-side entry passing through fault fracture zone

  • 摘要: 以钱营孜煤矿W3 220机巷为工程背景,基于采空侧煤体内外应力场分布特征及护巷窄煤柱的极限平衡理论,结合矿井具体地质条件,确定窄煤柱合理留设宽度;采用FLAC 3D数值模拟软件分析相邻工作面回采及掘进沿空煤巷穿越断层破碎带条件下的不同剖面位置围岩应力分布状态和塑性破坏响应特征,明确窄煤柱沿空煤巷过断层破碎带围岩控制的难点与巷道支护对策,并针对性地提出“超前注浆加固+高强度高预应力锚杆+顶板补强长锚索+KTM4钢带+菱形钢筋网”联合支护技术。研究发现:基于理论计算与现场实际,确定缓倾斜中厚煤层沿空煤巷过断层破碎带护巷窄煤柱宽度留设的合理范围为5.2~7.1 m;模拟开挖沿空煤巷穿越断层时,巷道断面发生改变,应力发生较大调整,实体煤侧与煤柱侧不再有应力集中现象,煤柱受力极弱,煤巷围岩塑性破坏范围进一步扩大,巷道发生剧烈挤压变形。工程实践表明,支护完成36 d后巷道收敛变形趋于稳定,煤柱侧顶板、实体煤侧顶板、煤柱帮及实体煤帮最大变形量分别为66、62、59、47 mm,且本工作面回采期间,沿空煤巷整体变形量较小,没有影响工作面的正常回采,6 m窄煤柱和强力联合支护技术保证了沿空煤巷过断层破碎带围岩的稳定。

     

    Abstract: Taking W3 220 mining roadway of Qianyingzi Coal Mine as the engineering background, based on the distribution characteristics of internal and external stress field of gob-side coal mass and the limit equilibrium theory of narrow coal pillar for roadway protection, and combined with the specific geological conditions of the mine, the reasonable width of narrow coal pillar was determined; under the condition of adjacent working face mining and gob-side entry driving passing through fault fracture zone, FLAC 3D numerical simulation software was used to analyze the stress distribution and plastic failure response characteristics of surrounding rock at different section positions. The paper expounded the surrounding rock control difficulties and roadway support countermeasures of narrow coal pillar gob-side entry passing through fault fracture zone, and put forward the combined support technology of "advance grouting reinforcement + high strength and high pre-stressed bolt + roof reinforcement long cable + KTM4 steel belt + rhombus steel mesh". The results show that: based on theoretical calculation and field practice, the reasonable width of narrow coal pillar is 5.2 m to 7.1 m for gob-side entry of gently inclined medium thick coal seam passing through fault fracture zone; when simulated gob-side entry passes through the fault, the cross-section of the roadway changes and the stress is adjusted greatly. There is no stress concentration at the solid coal side and the coal pillar side. The stress of the coal pillar is very weak, the plastic damage range of the surrounding rock of the roadway is further expanded, and the roadway is subjected to severe extrusion deformation. The engineering practice shows that the convergence deformation of roadway tends to be stable 36 d after the support completion, and the maximum deformation of coal pillar side roof, solid coal side roof, coal pillar side and solid coal side is 66 mm, 62 mm, 59 mm and 47 mm respectively, the overall deformation of gob-side entry is small during the mining period and does not affect the normal mining of the working face, 6 m narrow coal pillar and strong combined support technology can ensure the stability of surrounding rock of gob-side entry passing through fault fracture zone.

     

/

返回文章
返回