倾斜煤层条带开采煤柱群长期稳定性研究  

Research on long-term stability of coal pillar group in strip mining of inclined coal seam

作　　者：陈远峰 杨静[1] 马占国 茅献彪 CHEN Yuanfeng;YANG Jing;MA Zhanguo;MAO Xianbiao(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,Xuzhou 221116,China)

机构地区：[1]中国矿业大学力学与土木工程学院,江苏徐州221116 [2]深部岩土力学与地下工程国家重点实验室,江苏徐州221116

出　　处：《煤矿安全》2024年第11期146-153,共8页Safety in Coal Mines

基　　金：国家自然科学基金资助项目(50490273);国家重点研发计划资助项目(2019YFE0118500);江苏省卓越博士后计划资助项目(JB0205039)。

摘　　要：在“三下”条带采煤法等留煤柱开采方式中,煤柱群的长期稳定性对于矿井安全高效绿色开采至关重要。基于煤柱与围岩的相互作用关系,建立了倾斜煤层留设煤柱的平面应变模型,并采用Rits法推导了煤柱应力场与位移场的解析表达式。在此基础上,结合某村庄条带开采实际,建立了倾斜煤层煤柱群流变的FLAC3D数值计算模型,并基于Burgers组合蠕变黏弹塑性本构模型与数值模拟结果,探讨了时间效应对煤柱群长期稳定性的影响。理论与数值研究结果表明:受煤层倾角的影响,单个煤柱的水平位移约为其竖向位移的2倍以上;在上覆岩层重力长期作用下,各煤柱两帮在蠕变1 d时即进入塑性屈服状态,并呈现出剪切破坏形式;煤柱埋深越大,任意时刻煤柱塑性区范围、应力及位移峰值越高,且煤柱达到稳定蠕变阶段所需的时间从75 d逐渐增大到120 d以上。In the strip coal mining under buildings,railways and water-bodies and other retaining coal pillar mining methods,the long-term stability of coal pillar group is of paramount importance to the safe and efficient green mining.Based on the interaction relationship between coal pillar and surrounding rock,the plane strain model of retaining coal pillar in inclined coal seam is established,and the analytical expressions of coal pillar stress field and displacement field are deduced by using Rits method.On this basis,combined with the actual strip mining in a certain village,the FLAC3D finite difference numerical simulation method is used to establish a numerical calculation model for the long-term stability of coal pillars in inclined coal seams.Based on Burgers combined creep viscoelastic-plastic constitutive model and numerical simulation results,the effect of time and coal pillar width on long-term stability of coal pillar group is studied.Theoretical and numerical research results show that,affected by the inclination angle of the coal seam,the horizontal displacement of a single coal pillar is more than twice of its vertical displacement.Under the long-term action of the gravity of the overlying strata,the two sides of each coal pillar enters the plastic yielding state after 1 day of creep,and presents a shear failure form.The greater the buried depth of coal pillar,the higher the plastic zone range,stress and displacement peak value of coal pillar at any time,and the time required for coal pillar to reach the stable creep stage gradually increases from 75 days to more than 120 days.

关 键 词：倾斜煤层 条带开采 Rits法 煤柱群 长期稳定性 

分 类 号：TD823.6[矿业工程—煤矿开采]