推进速度对大采高工作面矿压显现的影响研究

发布时间：2018-08-23 09:23

【摘要】：通过对淮南矿业集团张集矿1611(3)大采高工作面不同推进速度下的矿压实测,研究不同推进速度下的矿压显现规律,实测发现：提高推进速度,周期来压步距、来压持续长度增幅明显,工作面超前应力峰值增大,影响范围变小,形成应力集中现象,片帮冒顶发生情况有所减低。运用材料力学、岩石力学相关知识,推导了采煤面上覆关键层的判别条件、岩梁荷载,以“关键层理论”为指导,分析1611(3)综采面上覆岩层结构,再结合损伤力学、大采高采场关键层相关研究成果,分析1611(3)大采高工作面在不同推进速度下采场上覆关键层“悬臂梁”结构的垮落运动型态,提出：工作面慢速推进时“短悬臂一砌体梁”交替垮落式和快速推进时“长悬臂”直接垮落式；慢速推进时周期来压步距和来压持续长度变小,来压步距呈现一大一小变化,具有明显的非均匀性；快速推进时“长悬臂梁”直接垮落式,造成工作面周期来压步距和来压持续长度的加大。采用FLAC3D数值模拟软件,以1611(3)大采高工作面为工程背景,通过改变单位时间截深模拟不同推进速度下采场围岩应力、塑性破坏区及关键层下沉运动,模拟结果与现场实测基本一致。针对大采高工作面末端回撤易压架问题,在对1611(3)工作面不同推进速度的矿压规律的研究基础上,分析先采用了降低推进速度减小顶板来压对采面的影响,再确定在合理的停采线位置(隔离煤柱)进行停采让压,避免工作面与回撤通道贯通时处于顶板来压状态而阻碍工作面安全回撤。
[Abstract]:Through measuring the rock pressure of Zhangji 1611 (3) large mining face of Huainan Mining Group under different advancing speed, the paper studies the regularity of mine pressure appearance under different propelling speed. The measured results show that: to increase the speed of propulsion, the interval between periodic pressure and pressure is increased. The continuous length of pressure increases obviously, the peak value of leading stress increases, the influence range becomes smaller, the phenomenon of stress concentration is formed, and the occurrence of roof fall is reduced. Based on the relevant knowledge of material mechanics and rock mechanics, the distinguishing conditions and the load of rock beam on the coal mining surface are derived. Under the guidance of "critical layer theory", the overburden structure of 1611 (3) fully mechanized coal face is analyzed, and the damage mechanics is combined. Based on the related research results of key strata in large mining height stope, the collapse motion patterns of "cantilever beam" structure in 1611 (3) large mining face overlying key strata under different advancing speeds are analyzed. It is proposed that the "short cantilever masonry beam" collapses alternately when the working face is moving slowly and the "long cantilever" directly collapses in the case of rapid propulsion, and the interval between the periodic pressure and the continuous pressure becomes smaller, and the pressure step distance changes greatly and slightly during the slow advance. The "long cantilever beam" directly collapses during the rapid advance, which results in the increase of the step distance and the continuous length of the working face. Using FLAC3D numerical simulation software, taking 1611 (3) large mining face as the engineering background, the stress of surrounding rock, the plastic failure zone and the subsidence of key strata are simulated by changing the unit time depth at different propelling velocities. The simulation results are in good agreement with the field measurements. Aiming at the problem of retreating easy pressure frame at the end of large mining face, on the basis of study on the law of mine pressure of 1611 (3) working face with different advancing speed, this paper first analyzes the influence of reducing pushing speed and reducing roof pressure on mining face. Finally, it is determined that stoppage pressure should be carried out at a reasonable stoppage position (isolating coal pillar) to avoid the roof pressure state when the face is connected with the withdrawal passage, thus hindering the safe withdrawal of the working face.
【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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