基于铁木辛柯梁理论的端面冒顶机理及相似模拟试验研究  

Roof cavity mechanism in the face-to-tip area based on Timoshenko beam theory and its physical modeling

作　　者：宋高峰 魏臻 杨胜利[3] 王兆会[3] 孔德中[4] 安栋 SONG Gaofeng;WEI Zhen;YANG Shengli;WANG Zhaohui;KONG Dezhong;AN Dong(School of Civil Engineering,North China University of Technology,Beijing 100144,China;Department of Engineering Physics,Tsinghua University,Beijing 100084,China;School of Energy and Mining Engineering,China University of Mining and Technology-Beijing,Beijing 100083,China;Mining College,Guizhou University,Guiyang,Guizhou 550025,China)

机构地区：[1]北方工业大学土木工程学院,北京100144 [2]清华大学工程物理系,北京100084 [3]中国矿业大学(北京)能源与矿业学院,北京100083 [4]贵州大学矿业学院,贵州贵阳550025

出　　处：《采矿与安全工程学报》2023年第2期304-312,321,共10页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(52004010);北京市属高等学校优秀青年人才培育计划项目(BPHR202203036);北京市教委科技计划一般项目(KM202010009001)。

摘　　要：为研究端面冒顶机理及支架与围岩相互作用关系,采用铁木辛柯梁理论建立了工作面直接顶稳定性力学模型,并开发了新型分布式顶梁荷载监测系统和数字图像覆岩位移监测系统,开展了端面冒顶及覆岩切落大比例相似模拟试验,获得了不同因素影响下的工作面顶板变形变化规律,以及端面顶板冒落全过程、覆岩位移场演化规律和液压支架工作阻力曲线。研究结果表明:提高支架刚度或当直接顶弹性模量较大时,工作面顶板挠度和转角显著降低;随着煤层埋深的增大,工作面顶板挠度和转角变形参量也逐渐增大。直接顶岩层泊松比与直接顶的变形成正比,但对工作面顶板稳定性影响较为有限。根据模型试验中端面顶板(煤)的稳定性将相似模拟工作面的推进过程划分为端面稳定阶段、端面冒顶阶段和覆岩垮落阶段。在端面稳定阶段,顶板逐渐破碎且切顶线前移至支架上方,造成支架低头和接顶不实,支架最大工作阻力由2.5 kN逐渐降低至1.7 kN;在端面冒顶阶段,端面冒顶向上延展并发生3次冒落,冒落形态由“扁梯形”演化为“三角形”,工作阻力进一步降低为1.3 kN;在覆岩垮落阶段,支架上方岩层沿煤壁发生整体切落并向采空区倾倒垮落,模型支架模拟出现场完整的增阻过程,工作阻力增加至1.7 kN。For a better understanding of the mechanism of the roof cavity in the face-to-tip area and the shield-strata interaction,a roof stability mechanical model was developed based on the Timoshenko beam theory.A new type of canopy load measuring system for a physical shield and the digital image system for measuring strata displacement were also developed and used in the large-scale physical modeling study to reproduce the roof cavity and the massive roof fall in the face area.The deformation of the im mediate roof was obtained under different influencing factors including the shield stiffness,the immediate roof elastic modulus,the buried depth of the coal and Poisson’s ratio of the roof strata,as well as the processive development of the roof fall,the strata displacement field and the variation of the shield load.The results show that:the deflection and rotation angle of the immediate roof were significantly improved when the shield stiffness was increased or at a high strata modulus.The deformation,i.e.,the deflection and rotation angle of the immediate roof,increased with an increase of the buried depth,though the Poisson’s ratio increases the deformation of the immediate roof in a rather insignificant manner.The development of the physical longwall face was classified into three stages,i.e.,the stable stage,the cavity stage and the major fall stage,based on the stability of the roof in the face-to-tip area.In the stable stage,the immediate roof became broken and the roof fall cutting line moved forward to the position above the shield canopy,leading to the head drop of the canopy and incomplete contact between the canopy and the roof.The maximum shield load,therefore,decreased from 2.5 kN to 1.7 kN.During the roof cavity stage,however,the roof cavity occurred 3 times and developed upward.The caved shape evolved from a trapezoid to a triangle,and the shield load saw a further decline to 1.3 kN.During the massive roof fall stage,the entire fall of the roof along the coal wall occurred and the rotation of the mas

关 键 词：端面冒顶 铁木辛柯梁 支架-围岩相互作用关系 顶梁载荷 相似模拟 

分 类 号：TD323[矿业工程—矿井建设]