深部沿空掘巷含软弱夹层顶板离层破坏特征及控制研究  

Study on failure characteristics and control of roof separation with weak interlayer of deep gob-side entry driving

作　　者：常聚才[1,2] 郭钇君 吴博文 史文豹[1,2] 齐潮 王宏达 CHANG Jucai;GUO Yijun;WU Bowen;SHI Wenbao;QI Chao;WANG Hongda(State Key Laboratory for Safe Mining of Deep Coal Resources and Environment Protection,Anhui University of Science and Technology,Huainan 232001,China;School of Mining Engineering,Anhui University of Science and Technology,Huainan 232001,China)

机构地区：[1]安徽理工大学深部煤炭安全开采与环境保护全国重点实验室,安徽淮南232001 [2]安徽理工大学矿业工程学院,安徽淮南232001

出　　处：《煤炭科学技术》2024年第9期88-102,共15页Coal Science and Technology

基　　金：国家自然科学基金资助项目(52174105,52204079);安徽省优秀科研创新团队资助项目(2023AH010023)。

摘　　要：含软弱夹层顶板对深部沿空掘巷稳定性具有重要影响,为有效控制深部高偏应力沿空掘巷含软弱夹层顶板离层破坏,基于含软弱夹层组合体试件力学试验及受采动影响下沿空掘巷数值模拟试验,获得了软弱夹层层厚、层数和层位对顶板的影响以及偏应力条件下含软弱夹层顶板离层演化规律,阐释了含软弱夹层顶板沿空掘巷失稳主要原因,结合顶板支护载荷和煤柱支撑载荷下的悬臂梁力学模型,对含软弱夹层顶板控制要点进行分析,进而提出离层控制方法。结果表明:随着软弱夹层厚度和层数增加,对组合体力学特性劣化影响逐渐变大,软弱夹层位于低位时对组合体试件的劣化影响强于高位,组合体试件破裂均由软弱夹层产生,并随着层厚、层数和层位的不同呈现差异化破裂发育特征。沿空掘巷后主剪切破裂带由顶板左肩角产生并与软弱夹层邻近岩层破裂区相互连接,导致软弱夹层离层严重,主剪切破裂带发育形态和顶板非协调变形程度随主应力偏转角度以及软弱夹层层厚、层数和层位变化,揭示了含软弱夹层顶板沿空掘巷失稳机理。推导了顶板支护载荷和煤柱支撑载荷下的巷道顶板离层解析式,发现软弱夹层在锚固区内的离层量比在锚固区外减少79%,离层大小各主控因素影响程度及其控制优化顺序依次为煤柱支撑载荷—顶板支护载荷—顶板弹性模量。针对深部沿空掘巷含软弱夹层顶板的离层规律和控制要点,提出了“提高煤柱承载能力、减少顶板裂隙发育、增加软弱夹层顶板变形协调性”的离层联合控制方法。现场离层监测显示顶板最大离层量为10 mm,表明该方法能有效控制含软弱夹层顶板离层。Roof with weak interlayer has significant influence on the stability of deep gob-side entry driving,to effectively control the separation of roof with weak interlayer in deep gob-side entry driving under high deviatoric stress,based on the mechanical experiment of composite specimen with weak interlayer and numerical simulation experiment of gob-side entry driving under the influence of mining,the influence of the thickness,number and position of weak interlayer and the evolution law of roof separation under high deviatoric stress conditions are obtained,the main reasons for separation of the roof with weak interlayers of deep gob-side entry driving are elucidated.The key points for controlling the roof with weak interlayer are analyzed using the mechanical model of cantilever beams under the support load and coal pillar support load,and the separation control method is subsequently proposed.The results show that the influence on the deterioration of the mechanical properties of the composite gradually becomes larger with the increase of the thickness and the number of layers of the weak interlayer,the influence on the deterioration of the composite with weak interlayer at the low position is stronger than that at the high position.The fracture of the composite specimen is produced by the weak interlayer,and the characteristics of the fracture development are different with its thickness,the number and position.The main shear failure zone generated at the left shoulder corner of the roof and connected to the adjacent rock failure area near the weak interlayer after gob-side entry driving,resulting in the separation of the weak interlayer,and the development morphology of main shear failure zone and non-coordinated degree deformation of roof vary with the deviation angle of principal stress and the thickness,number and position of weak interlayers,which revealed the instability mechanism of roof with weak interlayer of deep gob-side entry driving.The mechanical model of roof separation under the support load and t

关 键 词：沿空掘巷 深部开采 软弱夹层 剪切破裂带 顶板离层 变形协调 

分 类 号：TD322[矿业工程—矿井建设]