摘要
人工裂化煤岩体是主动改造煤岩体结构的有效手段,但人工致裂产生的人工裂缝的形态及参数等对于煤岩体结构的改造程度、对应力场的改善程度等,将影响到高应力的转移卸压程度。采用物理实验、数值模拟、理论分析和现场应用等方法,开展了人工裂化煤岩体的力学特性、应力场改变机制及控制方面的研究,得出含人工裂缝煤岩体在不同裂缝类型及参数条件下的力学特性和破坏失稳规律不同,随着裂缝长度、密度的增加或者裂缝角度在30°~45°,试块的弹性模量、强度、能量释放程度均逐渐降低;阐释了人工裂化煤岩体的弱结构体特征,分析了煤岩裂化弱结构体随裂缝长度、角度、间距及组数变化对宏观应力的改变规律,进而提出了基于煤岩裂化弱结构体的应力转移理论框架,建立了煤岩裂化弱结构体应力转移控制流程,给出了基于水力压裂的煤岩裂化控制参数的确定方法;针对淮北矿业祁南煤矿313工作面跨底板大巷回采的动压影响问题,现场实施了水力压裂大巷顶板岩层形成弱结构体卸压的巷道围岩控制方法,水力压裂后孔壁出现了明显的裂缝,跨采期间底板大巷的变形量显著减小,巷道得到了有效控制。
Artificial cracking is an effective means to actively transform the structure of coal-rock mass.However,the influence of shape and parameters of coal-rock mass by artificial cracking on transformation degree of its structure and improvement of stress field will have an impact on the transfer and pressure relief degree of high stress.Through physical experiment,numerical simulation,theoretical analysis,and field application,mechanical properties,stress field change mechanism,and control of artificially cracked coal-rock mass were studied.The results have shown that mechanical properties and failure and instability laws of artificially cracked coal-rock mass are different under different fracture types and parameters.With the increase of crack length and density or crack angle in 30°~45°,elastic modulus,strength and energy release degree of the test block gradually decrease.The weak structure characteristics of artificially cracked coal-rock mass was explained,and the change law of coal-rock cracking weak structures to macroscopic stress with changes in crack length,angle,spacing,and group number was analyzed.The theoretical framework of stress transfer based on coal-rock cracking weak structure was proposed,control flow of coal-rock cracking weak structural stress transfer was established,and determining method of coal-rock cracking control parameters based on hydraulic fracturing was given.Finally,in order to solve dynamic pressure influence of mining across floor roadway in working face 313 of Qi’nan Coal Mine of Huaibei Mining Company,the roadway surrounding rock control method of weak structure pressure relief formed by roof strata of hydraulic fracturing roadway was implemented in the field.Obvious cracks appeared in the hole wall after hydraulic fracturing,the deformation of the floor roadway decreased significantly during the span mining period,and the roadway was effectively controlled.
作者
刘长友
刘江伟
LIU Changyou;LIU Jiangwei(School of Mines,China University of Mining&Technology,Xuzhou,Jiangsu 221116,China;College of Energy and Mining Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China)
出处
《采矿与安全工程学报》
EI
CSCD
北大核心
2022年第2期359-369,共11页
Journal of Mining & Safety Engineering
基金
国家自然科学基金项目(52074267)。
关键词
煤岩体裂化
弱结构体
应力转移
卸压
水力压裂
coal-rock mass cracking
weak structure
stress transfer
pressure relief
hydraulic fracturing
作者简介
刘长友(1965-),男,山东省东营市人,教授,工学博士,博士生导师,主要从事矿山压力与岩层控制方面的研究;通信作者:刘江伟,E-mail:jiangweiliu@cumt.edu.cn,Tel:15162119505。
