近距离浅埋煤层房柱下开采动压机理研究

发布时间：2018-05-30 01:26

本文选题：浅埋煤层 + 重复采动　；参考：《西安科技大学》2015年硕士论文

【摘要】：随着陕北侏罗纪浅埋煤层开采规模不断扩大,许多矿井开采的浅部煤炭资源逐渐枯竭,煤层开采已经转入浅部煤层的下层煤开采。由于开采距离较近,上部煤层采空区遗留煤柱对下部回采工作面产生极大的影响,常引发下部煤层回采工作面出煤柱的过程的动压灾害,造成压架事故。本论文针对近距离浅埋煤层长壁工作面通过房柱采空区宽煤柱过程中的动压现象和压架事故的特殊性,结合陕北集团韩家湾煤矿下部煤层赋存状况,采用物理相似模拟实验、计算机数值模拟和理论分析等综合手段,从应力场的变化和岩层运移的角度分析回采工作面出房柱区动压机理分析可能引发动压事故的原因。揭示了下部煤层回采工作面过煤柱的动压现象的机理。下部回采工作面出房柱区的过程中,工作面超前支撑压力的动载作用与煤柱作用下的静载作用叠加,并始终作用在工作面的前方。回采过程中引起房柱区底板下沉,房柱区遗留煤柱上部关键岩块回转失稳,失稳的关键岩块和煤柱上部层岩在Z方向的运动不再一致,上部覆岩运动速度较快,其动能通过煤柱作用于下部岩层,煤柱上部关键岩块的动能通过煤柱传递至下部覆岩内,这三者叠加作用在回采工作面的前部,形成能量集聚区。煤柱底板岩层在其上的高集中应力作用下岩层承载能力降低。同时,由于工作面推进过程中提供的空间及其的扰动影响,使得集聚的能量突然释放至工作面,使得工作面发生剧烈的动压现象。动压的发生具有突然性,剧烈性,对工作面的安全与支护具有极大的危害性。下部回采工作面通过其上部房柱区时,必须预先处理其内遗留的煤柱。通过计算机模拟实验分析煤柱宽度是影响其下动压的关键因素,因此提出通过超前预裂房柱区内未失稳的煤柱的手段控制下部回采动压的技术措施。
[Abstract]:With the expansion of the mining scale of shallow coal seam in Jurassic in Northern Shaanxi, the shallow coal resources of many mines are gradually exhausted, and the coal seam mining has been transferred to the lower coal mining of shallow coal seam. Because of the close mining distance, the coal pillar left over from the goaf of the upper coal seam has a great influence on the lower coal mining face, which often leads to the dynamic pressure disaster in the process of coal pillar extraction in the lower coal seam mining face, resulting in the pressure frame accident. In this paper, according to the phenomenon of dynamic pressure and the particularity of press frame accident in the long wall face of short distance shallow coal seam passing through the wide pillar of roof pillar, combined with the occurrence of coal seam in the lower part of Hanjiawan Coal Mine of Northern Shaanxi Group, the physical similarity simulation experiment is adopted. By means of computer numerical simulation and theoretical analysis, the causes of dynamic pressure accident caused by dynamic pressure in pillar area of mining face are analyzed from the point of view of the change of stress field and the movement of rock layer. This paper reveals the mechanism of dynamic pressure phenomenon of coal pillar in the lower coal seam mining face. In the process of coming out of the pillar area of the lower mining face, the dynamic load action of the leading supporting pressure of the working face is superposed with the static load action under the action of the coal pillar, and it always acts in front of the working face. In the process of mining, the bottom plate of the roof pillar area is sinking, the key rock block left over from the roof pillar area is rotated and unstable, the movement of the key rock block which is unstable is no longer consistent with that of the upper layer rock in the Z direction, and the velocity of the upper overburden rock is relatively fast. The kinetic energy of the coal pillar acts on the lower strata, and the kinetic energy of the key rock blocks above the pillar is transferred to the lower overburden rock through the pillar. These three superpositions act on the front part of the mining face and form an energy accumulation area. Under the action of high concentration stress, the bearing capacity of coal pillar floor is decreased. At the same time, due to the space provided by the working face and its disturbance, the accumulated energy is suddenly released to the working face, which makes the working face violent dynamic pressure phenomenon. The occurrence of dynamic pressure is sudden and violent, which is harmful to the safety and support of working face. When the lower mining face passes through the upper roof pillar area, it must deal with the coal pillar left behind in advance. The width of coal pillar is the key factor to influence the lower dynamic pressure of coal pillar by computer simulation experiment. Therefore, the technical measures of controlling the lower mining dynamic pressure by means of the unsteady pillar in advance pre-split room column area are put forward.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD823.81

【参考文献】