摘要
为解决极软煤层巷道的控制难题,以芦岭煤矿9号煤层(f=0.16~0.53)巷道为研究对象,采用FLAC5.0软件研究了锁腿锚杆与卸压钻孔实施前后U型钢支架的载荷分布规律及巷道变形特征。结果表明:U型钢支架施加锁腿锚杆后支架的稳定性和承载能力得到了明显改善,但巷道变形量并没有大幅度降低,单纯采用锁腿锚杆难以控制巷道的剧烈变形。卸压钻孔可以为围岩的碎胀变形预留一定的释放空间,缓解作用在U型钢支架上的压力,两者协同作用,可以充分发挥各自的优点,有效改善U型钢支架的支护效果。现场实践表明,实施钻孔卸压和锁腿锚杆后巷道回采期间的平均底鼓速度由2.0 mm/d减小至0.98 mm/d,两帮平均变形速度由2.64 mm/d减小到1.86mm/d,能够有效维护极软煤层巷道围岩的稳定。
To solve the problem of roadway maintenance in ultra-soft coal seams,the roadways in No. 9 coal seam at Luling Coal Mine,China were investigated in this study.The characteristics of load distribution on the U-steel and the roadways deformation before and after the usage of pressure-released boreholes and leg-locked bolts were modeled using FLAC5.0.The results show that the stability and bearing capacity of U-steel was significantly improved after the shed's legs being locked,but the roadway deformation was not significantly reduced,which meant only leg-locked bolts could not control the severe deformation of the roadway.As the pressure-released boreholes could reserve a certain free space for rock hulking deformation,which could relieve the pressure acting on U-steel,with the collaborative action of both pressure-released boreholes and leg-locked bolts,the supporting capability of U-steel could be effectively improved.The result of field survey showed the average speed of floor heave and rib to rib deformation during mining were reduced from 2.0 mm / d,2.64 mm / d to 0.98 mm / d,1.86 mm / d respectively,which meant it could maintain the stability of roadways in ultra-soft coal seam effectively.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2015年第10期2279-2286,共8页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2010CB226801)
中央高校基本科研业务费专项资金资助项目(2014QL01)
关键词
极软煤层
卸压钻孔
U型钢支架
锁腿锚杆
ultra-soft coal seam
pressure-released borehole
U-steel
leg-locked bolt
