摘要
针对分层开采中分层煤柱巷道大变形与控制难题,以老公营子煤矿I05(8)2轨道平巷为工程背景,分析巷道围岩大变形破坏特征及失稳机理。研究表明,中分层回采后采空区空间增大,上覆岩层关键块体再次回转下沉是造成煤柱巷道大变形的主要原因;分层开采中区段煤柱受多次采动影响,煤柱整体已发生塑性破坏,其稳定性和承载能力不断降低,无法为锚固体提供稳定的锚固基础是造成巷道大变形的内在因素。基于巷道失稳机理,提出"强化煤柱、增强锚固"的控制思路,具体控制机制为表面喷浆固结破碎煤体提高巷帮完整性,煤柱内部注浆填充粘结裂隙为锚固体提供稳定的锚固点,煤柱帮增加锚杆支护提高浅部围岩整体性,增大锚索预紧力提高煤柱的自承能力。现场实践表明,巷道围岩变形量满足安全生产要求,联合支护方案能够有效的控制巷道围岩大变形。
Aiming at the large deformation and control in the pillar roadway of slice mining,taking the I05(8)engineering background,the characteristics of large deformation and failure of surrounding rock and its instabi2 tailgate as the lity mechanism are analyzed.The research shows that the large deformation of tailgate is mainly caused by the expanding of goaf and the revo lving subsidence of key blocks in overlying strata after middle and lower slicing stoping.In the section of slice mining,the coalpill ar is affected by multiple mining,plastic failure has happened in the coal pillar,its stability and bearing capacity dec linesconstantly,and it can’t self-stabilize and slow down the subsidence of key blocks,which are the internal causes for the roadway large deformation.Based on the mechanism of roadway instability,the combined support scheme of surface grouting andconsolidation of broken coal is proposed to improve the integrity of roadway wall,using grouting inside of the coal pillar to fill the cracks and repair the damaged coal,thus to improve the self-supporting capacity of coal pillar,and bolting support on coal pill ar to improve the integrity of shallow surrounding rock and increase the pre-tightening force of anchor cable.The field practiceshows that,the roadway surrounding rock deformation can meet the safety production requirements,and the combined support scheme can control thelarge deformation of roadway surrounding rock.
作者
李国志
孙立军
LI Guo-zhi;SUN Li-jun(Laogongyingzi Coal Mine,Inner Mongolia Pingzhuang Energy Co.,Ltd.,Chifeng 024076,China)
出处
《煤炭工程》
北大核心
2020年第12期46-50,共5页
Coal Engineering
关键词
分层开采
煤柱
破碎围岩
巷道失稳
注浆加固
联合支护
slice mining
coal pillar
broken surrounding rock
roadway instability
grouting reinforcement
combined support
