大采高工作面薄层松软破碎顶板稳定性及控制技术研究

发布时间：2019-01-02 13:33

【摘要】：由于淮南潘谢矿区煤炭资源的紧张形势,因此开发潘谢矿区的A组煤具有重要意义。本文针对淮南矿区潘二煤矿11223工作面地质条件,理论分析了大采高工作面破碎顶板冒落的力学机理和破碎顶板的注浆加固机理。数值模拟和现场实测相结合的方法,对大采高工作面薄层松软破碎顶板稳定性及控制技术进行研究。运用FLAC3D数值模拟软件建立了三维数值计算模型,分别采用不同采厚和不同采宽的数值模拟手段,比较分析了工作面覆岩应力分布特征和薄层松软破碎顶板中应力特征；并利用数值模拟手段,比较分析了注浆前后工作面顶板下沉量和超前支承压力分布规律。研究结果表明： (1)不同采高条件下,工作面煤壁前方应力峰值位置、工作面切眼后方煤柱内应力峰值位置均与采高成一定的正比例关系,而采动影响范围与采高没有明显的关系； (2)在不同工作面长度条件下,随着工作面长度的增加,工作面采空区应力拱由平顶拱趋向马鞍形应力拱,工作面前方煤壁以及工作面后方煤柱侧应力拱扩展变化及范围基本相同； (3)沿走向工作面切眼后方煤柱内应力峰值及最大相对应力集中系数,与工作面长度成非线性正比；沿走向工作面煤壁前方应力峰值及最大相对应力集中系数,与工作面长度成非线性正比。 (4)随着距煤壁距离的增加,工作面后方顶板下沉量先逐渐增大,然后趋于稳定。顶板最大下沉量在未注浆时为345mm,注浆时为169mm,注浆段比未注浆段顶板下沉量明显减小,注浆对工作面顶板下沉起到了显著的控制左右。 (5)未注浆段工作面前方超前支承压力最大值为33MPa,超前应力集中系数峰值为3,注浆段工作面前方超前支承压力最大值为30MPa,超前应力集中系数为2.72,较未注浆段减小了9.3%；注浆后应力集中系数变小,顶板完整性增强,注浆段受超前压力影响程度较未注浆段小。研究成果可为现场提供理论参考,对淮南潘谢矿区大采高采场薄层松软破碎顶板的煤层安全回采提供一定的指导意义。
[Abstract]:Because of the shortage of coal resources in Panxie mining area in Huainan, it is of great significance to develop group A coal in Panxie mining area. According to the geological conditions of 11223 face of Paner Coal Mine in Huainan mining area, the mechanical mechanism of broken roof caving and grouting reinforcement mechanism of broken roof in large mining face are analyzed theoretically in this paper. The stability and control technology of thin layer soft broken roof in large mining face are studied by combining numerical simulation and field measurement. Three dimensional numerical simulation model was established by using FLAC3D software. The stress distribution characteristics of overburden and the stress characteristics in thin soft broken roof were compared and analyzed by using different mining thickness and different mining width respectively. By means of numerical simulation, the law of roof subsidence and leading support pressure distribution before and after grouting are compared and analyzed. The results show that: (1) under different mining height conditions, the peak position of stress in front of coal face wall and the peak position of stress in pillar behind cutting face are positively proportional to mining height. However, there is no obvious relationship between the influence range of mining and mining height. (2) under the condition of different working face length, with the increase of working face length, the stress arch in goaf of working face changes from flat top arch to saddle type stress arch, The variation and range of stress arch expansion in front coal wall and back coal pillar are basically the same. (3) the peak stress and the maximum relative stress concentration factor in the pillar are directly proportional to the length of the face; The peak stress and the maximum relative stress concentration factor in front of the coal wall along the strike face are nonlinear proportional to the face length. (4) with the increase of the distance from the coal wall, the amount of roof subsidence at the rear of the face increases gradually and then tends to be stable. The maximum subsidence of roof is 345mm without grouting and 169mm with grouting. The roof subsidence of grouting section is obviously smaller than that of non-grouting section, and grouting plays a significant role in controlling the roof subsidence of working face. (5) the maximum value of the leading support pressure, the peak value of the leading stress concentration factor and the leading stress concentration factor are 33MPa, 3and 30MPa, respectively, and the lead stress concentration factor is 2.72, respectively. Compared with the ungrouted section, the ratio of 9.3% was decreased. After grouting, the stress concentration factor becomes smaller, the roof integrity is enhanced, and the grouting section is less affected by the lead pressure than the non-grouting section. The research results can provide a theoretical reference for the field and provide certain guiding significance for the safe mining of thin layer soft broken roof of large mining height stope in Panxie mining area of Huainan.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD323

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