综采工作面末采阶段矿压显现规律研究

发布时间：2018-04-28 19:23

本文选题：浅埋煤层 + 回撤通道　；参考：《西安科技大学》2015年硕士论文

【摘要】：对于综合机械化采煤工艺而言,工作面搬家倒面是实现高产高效的重要环节。由于受到采动影响,回撤通道顶板运动明显,两帮煤体位移将显著增大,容易发生顶板冒落及严重片帮等问题,甚至造成压架事故,影响矿井正常生产。本文分析了回撤通道在动压影响下的矿压显现规律,确定回撤通道最有利的顶板破坏形式,同时对不同矿压控制措施的作用机理及适用条件进行研究,本文研究的主要内容和结论有:(1)回撤通道围岩压力分布分为巷道掘进阶段的围岩压力分布、受动采影响阶段的围岩压力分布以及工作面贯通阶段的围岩压力分布三个阶段。依据弹塑性理论,确定出了回撤通道受动采影响的起始距离。(2)当老顶在贯通前断裂,贯通后在回撤通道或煤柱上部未发生再次断裂,此时巷道处于相对稳定阶段,支架回撤时受影响相对较小,说明该种顶板破坏形式对巷道稳定最为有利。经过进一步分析,给出了顶板合理断裂位置的确定公式。(3)建立力学模型,对老顶—直接顶协调变形体系进行受力变形分析,推导得出周期来压步距的函数关系式,并分析得出周期来压步距主要影响因素包括直接顶弹性模量、直接顶厚度、老顶弹性模量、老顶厚度、老顶抗拉强度、上覆岩层厚度。(4)通过对张家峁14204综采工作面矿压数据进行分析,得出周期来压步距与回采速率的回归曲线,结果显示周期来压步距随回采速率的提高有增加,但增加的幅度有所差异。(5)建立了贯通前压力调节时的剩余煤柱力学分析模型,求解得出剩余煤柱临界宽度的函数关系式。通过因素分析发现,老顶断裂位置、工作面埋深、岩层间的摩擦角以及采煤高度对剩余煤柱稳定性起到关键作用。由于不同的控制措施有其特殊的适用条件,在末采阶段应根据老顶实际断裂情况,采取合理的采煤措施进行控制。本文研究为综采回撤技术在陕北矿区的应用提供了有益的实践经验,具有重要的工程实际意义,同时丰富和发展了矿山压力控制相关理论,具有重要的理论意义。
[Abstract]:For comprehensive mechanized coal mining technology, moving face face is an important link to realize high yield and high efficiency. Due to the influence of mining, the roof movement of the withdrawal passage is obvious, the displacement of the two groups of coal bodies will increase significantly, and the roof caving and serious slab cover problems will easily occur, even resulting in a pressure rack accident, which will affect the normal production of the mine. In this paper, the law of rock pressure behavior under the influence of dynamic pressure is analyzed, and the most favorable roof failure form is determined. At the same time, the action mechanism and applicable conditions of different mine pressure control measures are studied. The main contents and conclusions of this paper are as follows: (1) the pressure distribution of the surrounding rock in the withdrawal passage is divided into three stages: the surrounding rock pressure distribution in the tunneling stage, the surrounding rock pressure distribution in the stage affected by dynamic mining and the surrounding rock pressure distribution in the working face through stage. According to the elastic-plastic theory, the starting distance of recoil passage affected by dynamic mining is determined. (2) when the main roof is fractured before transfixion, and there is no refracture in the retreating passage or the upper part of coal pillar after through, the roadway is in a relatively stable stage. When the support is retreated, the influence is relatively small, which indicates that the roof failure is the most favorable to the stability of roadway. Through further analysis, the formula of determining the reasonable fracture position of roof is given. The mechanical model is established, and the stress deformation analysis of the main roof and direct roof coordinated deformation system is carried out, and the functional expression of the periodic pressure step distance is derived. The main influencing factors include direct top elastic modulus, direct top thickness, old top elastic modulus, main roof thickness, and main roof tensile strength. By analyzing the rock pressure data of Zhangjiaomao 14204 fully mechanized mining face, the regression curves of the interval between the periodic pressure step and the mining rate are obtained. The results show that the periodic pressure step increases with the increase of the mining rate. But the amplitude of increase is different. (5) the mechanical analysis model of residual coal pillar under pressure-regulating before transfixion is established, and the function formula of critical width of residual coal pillar is obtained. Through factor analysis, it is found that the position of the main roof fracture, the buried depth of the working face, the friction angle between the strata and the mining height play a key role in the stability of the residual coal pillar. Because different control measures have their special applicable conditions, reasonable coal mining measures should be taken in the stage of final mining according to the actual fracture of the main roof. The research in this paper provides useful practical experience for the application of fully mechanized mining withdrawal technology in the mining area of northern Shaanxi, and has important engineering practical significance. At the same time, it enriches and develops the relevant theories of mine pressure control, which is of great theoretical significance.
【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】：TD323

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