浅埋近距煤层过煤柱矿压显现规律研究

发布时间：2018-03-10 18:24

本文选题：浅埋近距煤层　切入点：过煤柱　出处：《西安科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：浅埋近距煤层上层开采结束后遗留的煤柱对下层开采影响很大,经常导致下部煤层开采矿压显现明显,甚至诱发冲击矿压等事故。因此本文以哈拉沟煤矿12101工作面为工程背景,对浅埋近距下煤层开采过煤柱时覆层垮落特征、裂隙演化规律及采场应力分布特征进行研究,对后续类似工作面的安全生产和稳定开采具有一定指导意义。论文建立下煤层工作面进煤柱、过煤柱、出煤柱(过空巷)三个不同阶段煤柱上方关键块体结构的力学模型,并对其稳定性进行了分析。通过FLAC3D模拟软件和相似材料模拟实验,对过煤柱时围岩应力分布和覆岩运动规律进行监测,将光纤Bragg光栅传感器与PPP-BOTDA技术应用到模拟实验中,对上覆关键层变形移动进行监测。结合12101工作面现场矿压观测数据,对工作面末采阶段过煤柱时的矿压规律进行分析。研究表明,哈拉沟煤矿12101工作面在过辅回撤巷道时,上覆1段煤柱整体随亚关键层在巷道底鼓破断线处回转,导致工作面压力突然增大,出现强矿压显现;进煤柱、过煤柱和出煤柱时的超前支承压力峰值分别为2.64 MPa、2.79 MPa和3.26 MPa,应力集中系数平均为1.48。工作面过1段煤柱时超前支承压力从上覆煤柱转移至12101工作面,出辅回撤巷及排矸巷时应力峰值达到最大,塑性区分析表明浅埋煤层开采条件下,工作面顶板呈切落式破断。现场监测结果表明在过空巷时支架支护阻力明显大于过煤柱阶段时支架的支护阻力。在相似模型中光纤Bragg光栅监测结果与岩层移动规律一致,且过辅回撤巷时光纤H1的布里渊频移曲线右侧峰值发生突增,证明了上覆煤柱在此阶段发生整体下沉,导致出现强矿压显现。
[Abstract]:The pillar left over from the upper layer of shallow and close coal seam has a great influence on the lower coal mining, which often leads to obvious mining pressure in the lower coal seam, and even induces accidents such as impact mine pressure. Therefore, this paper takes the 12101 working face of Haragou Coal Mine as the engineering background. The characteristics of overburden collapse, fracture evolution and stope stress distribution during coal pillar mining in shallow and short distance coal seam mining are studied. It has certain guiding significance for the safety production and stable mining of the following similar coal face. This paper establishes the mechanical model of the key block structure above the coal pillar in three different stages: the coal pillar, the coal pillar and the coal pillar in the next coal face. Through FLAC3D simulation software and similar material simulation experiment, the stress distribution of surrounding rock and the law of overlying rock movement during coal pillar are monitored, and the fiber Bragg grating sensor and PPP-BOTDA technology are applied to the simulation experiment. The deformation movement of the overlying key strata is monitored. Combined with the field pressure observation data of 12101 face, the law of mine pressure during the coal pillar passing in the final mining stage of the working face is analyzed. The study shows that the 12101 face of Hagagou coal mine is in the process of over-auxiliary retracement roadway. The whole coal pillar of the first section of the overlying layer rotates with the sub-key layer at the break line of the roadway bottom, which results in the sudden increase of the working face pressure and the appearance of the strong mine pressure. The peak value of leading support pressure in coal pillar and coal pillar is 2.64 MPa and 3.26 MPA, respectively, and the average stress concentration factor is 1.48.The leading support pressure is transferred from overlying pillar to 12101 face. The peak stress of roadway and gangue roadway reaches the maximum. The plastic zone analysis shows that under the condition of shallow coal seam mining, The field monitoring results show that the support support resistance is obviously higher than the support support resistance in the coal pillar stage. In the similar model, the monitoring results of the fiber Bragg grating are consistent with the rock movement law. Moreover, the peak value of Brillouin frequency shift curve of fiber H1 on the right side of the Brillouin frequency shift curve of fiber H1 increases suddenly when the roadway is retreated, which proves that the overlying coal pillar is sinking as a whole at this stage, which leads to the appearance of strong ground pressure.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD323

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