摘要
煤层开采过程中裂隙的演化对于煤矿顶板导水通道的形成至关重要。以研究区煤矿2煤首采工作面为地质原型,采用相似材料模型试验研究了不同开采距离下覆岩应力的动态演化过程。基于信息论中的信息熵,对模型中应力的监测结果进行计算,得到不同开采距离下的应力信息熵,对采动覆岩应力变化过程进行定量化的动态分析。结果表明:应力信息熵的演化分为3个阶段,即发生期、扩展期和稳定期。应力信息熵随开采距离的增加呈波动上升态势,这是由覆岩系统内部离层和导水裂隙带的发育情况引起的。当离层产生以及导水裂隙带发育时,应力信息熵增大;当裂隙闭合时,应力信息熵会相应减小。在不同的空间演化中,应力信息熵也存在着较大的差异性。从竖向监测线来看,开切眼附近的应力信息熵随着工作面的推进波动减小,终采线附近的应力信息熵随着工作面的推进波动增大,中间位置的应力信息熵在开采前后基本一致;从横向监测线来看,在应力信息熵的扩展期裂隙发育最为强烈。通过对矿井水害致灾危险源进行辨识,揭示导水通道的形成阶段,在相似材料模型开挖至45~105 cm期间为应力信息熵的扩展期,此阶段导水通道形成。工程实例表明应力信息熵的扩展期与水害发生的危险期具有一致性,在此阶段及时采取防治措施,避免水害事故的发生。
The evolution of roof fracture in coal seam mining is important for the formation of roof water passage in coal mine.The first mining face of No.2 coal seam in the research area is taken as geological background,and the dynamic evolution process of overburden stress under different mining distances was studied by using similar material model.Based on the information entropy of information theory,the moni-toring results of stress in the model were calculated to obtain the stress information entropy under different mining distances,so as to conduct a quantitative dynamic analysis of overburden strata stress induced by mining.The results show that the evolution of stress information entropy can be divided into three stages:occurrence period,expansion period and stable period.With the increase of mining distance,the stress information entropy is fluctuating and rising,which is caused by the development of separation and the wa-ter-conducting fracture zone in the overlying strata system.The stress information entropy increases when the separation is formed and the water-conducting fracture zone is developed,and decreases when the fracture is closed.In different spaces,there are great differences in stress information entropy.From the vertical moni-toring line,the stress information entropy near the open-off cut position decreases with the advance of the working face,and the stress information entropy near the stop line position increases with the advance of the working face.The stress information entropy at the middle position is basically the same before and after mining.From the horizontal monitoring line,the fracture develops most strongly in the expansion period of stress information entropy.By identifying the hazard sources of mine water disaster,the formation stage of water passage is revealed.During a similar material model excavation from 45 cm to 105 cm,this is the expansion period of stress information entropy,and the water passage is formed in this stage.The engineering example shows that the extension peri
作者
杨鹏
杨伟峰
张鑫全
王振荣
杨茂林
YANG Peng;YANG Weifeng;ZHANG Xinquan;WANG Zhenrong;YANG Maolin(School of Resources and Geosciences,China University of Mining and Technology,Xuzhou 221116,China;China Railway Major Bridge Reconnaissance and Design Institute Group Co.,Ltd.,Wuhan 430050,China;Shendong Coal Branch,China Shenhua Energy Co.,Ltd.,Shenmu 719315,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2021年第9期3006-3014,共9页
Journal of China Coal Society
基金
国家重点研发计划资助项目(2017YFC0804101)。
关键词
覆岩应力
信息熵
矿井水害
相似材料模型
导水通道
overlying strata stress
information entropy
mine water disaster
similar material model
water passage
