预掘回撤通道末采围岩破坏机制研究  

Study on failure mechanism of withdrawal channel's surrounding rock during last mining period

作　　者：贺艳军 宋亚新 石占山 李俊奇 陈凯 李治平 HE Yanjun;SONG Yaxin;SHI Zhanshan;LI Junqi;CHEN Kai;LI Zhiping(Mining Research Institute,Inner Mongolia University of Science and Technology,Baotou Inner Mongolia 014010,China;Lijiahao Coal Mine,Shenhua Baotou Energy Co.,Ltd.,Ordos Inner Mongolia 017000,China;School of Mines,Liaoning Technical University,Fuxin Liaoning 123000,China)

机构地区：[1]内蒙古科技大学矿业研究院,内蒙古包头014010 [2]神华包头能源有限责任公司李家壕煤矿,内蒙古鄂尔多斯017000 [3]辽宁工程技术大学矿业学院,辽宁阜新123000

出　　处：《中国安全科学学报》2022年第2期158-166,共9页China Safety Science Journal

基　　金：国家自然科学基金青年科学基金资助(52004118);辽宁省教育厅青年科技人才“育苗”项目(LJ2019QL005,LJ2020QNL009)。

摘　　要：为保证工作面安全高效回撤,通过理论分析及现场观测法,研究综采工作面末采期间回撤通道围岩应力分布及破坏特征,提出垛架支撑力控制顶板围岩破坏机制及方法,得到垛架最小支撑力计算方法。结果表明:回撤通道围岩集中应力与工作面前方支承压力逐步叠加,导致剩余煤柱由两侧向中部逐渐破坏,当两侧破坏区连通时,煤柱上方直接顶跨距增加为原来的2倍,且载荷较大。该应力及跨距满足直接顶失稳条件时,直接顶在工作面未贯通前发生预先破坏,进而导致贯通前发生冒顶。调整垛架初撑力能够减小回撤通道侧煤柱叠加应力值,减小剩余煤柱失稳时对应的煤柱宽度,减小直接顶对应的跨距,避免直接顶破坏,保证回撤顺利进行。In order to make the working face withdrawal safe and efficient,the stress distribution and failure characteristics of withdrawal channel's surrounding rock in fully-mechanized area during last mining period were studies through theoretical analysis and field observation.Then,failure mechanism and method for roof surrounding rock control by supporting force of cog timbering were proposed,and calculation method of minimum initial support force of cog timbering was obtained.The results show that concentrated stress of the withdrawal channel's surrounding rock is gradually superimposed with the bearing pressure in front of working face,which leads to the gradual failure of remaining coal pillar from both sides to the middle.When the failure areas on both sides are connected,the direct top span above coal pillar is increased by 2 times,and the load is large.When the stress and span meet the instability conditions of direct roof,the latter is damaged before working face is cut through,thus leading to roof fall before penetration.Adjusting the initial support force of cog timbering can reduce superimposed stress value of coal pillar at the side of withdrawal channel,corresponding coal pillar width when remaining coal pillar loses stability and the span of direct roof,thus avoiding shear failure and ensuring smooth withdrawal.

关 键 词：回撤通道 破坏机制 垛架支撑力 末采期间 叠加应力 

分 类 号：X936[环境科学与工程—安全科学]