煤巷采后顶板极限悬顶机理与沿空留巷应用研究

发布时间：2018-04-07 15:51

本文选题：煤巷顶板　切入点：极限悬顶　出处：《中国矿业大学》2016年硕士论文

【摘要】：针对煤层巷道项板采后极限悬项问题,应用理论分析、数值模拟和工程验证等综合手段,研究了不同项板情况下巷道极限悬项距的数学方程,分析了不同因素对极限悬项的影响,解释了巷道项板极限悬项机理,基于研究成果提出切项沿空留巷技术,得出的主要结论如下：(1)论文基于三种典型项板条件,通过建立相应的力学模型,分别得到巷道项板采后极限悬项距的计算表达式：坚硬岩层项板巷道、深井巷道顶板分别为近距离煤层未冒通情况下冒通情况下通过灵敏度分析法,对坚硬项板情况下巷道项板悬项距的影响因素进行分析评价,结果表明,塑性区宽度对悬项距的影响最大,其次依次为巷道宽度、极限抗拉强度、支撑强度、锚固强度、分层厚度,最后为开采深度。(2)实验确定项底板岩层力学性能指标,采用FLAC3D数值分析软件,分别模拟了巷内支护强度对深井巷道项板极限悬项距地影响,巷旁支护强度对近距离煤层极限悬项距的影响,煤壁强度对坚硬项板巷道极限悬项状态的影响。结果表明对于不同的巷内支护强度,侧向悬顶能力受到影响,当支护强度达到一定值后,再增大强度对侧向悬顶长度影响甚微。单纯的提高煤壁强度对巷道项板的侧向悬项影响较小,也不会明显改变工作面侧向与超前方向支承压力分布规律。巷旁支护强度对巷道项板悬项影响较大,且存在一个影响范围,相比于无巷旁支护时悬顶长度增大约50%。(3)基于研究成果介绍了两种工程应用,给出近距离煤层切项沿空留巷巷旁合理支护阻力确定依据,并对巷旁支护结构的稳定性控制提出判据,提出巷道支护技术遵循的原则。明确了厚硬底板岩层采后危害,介绍了顶板稳定性控制的处理方法,并给出了预裂坚硬项板的基本参数确定依据。(4)近距离煤层极限悬项距对切项沿空留巷工艺及采后巷道项板治理意义重大,工程应用中根据实际需求对项板极限悬项距的要求,灵活调整留巷巷道宽度、巷旁支撑强度、锚固强度等参数。
[Abstract]:Aiming at the problem of limit overhang after mining in coal roadway, the mathematical equation of the limit suspension of roadway under different item slab is studied by means of theoretical analysis, numerical simulation and engineering verification.This paper analyzes the influence of different factors on the limit suspension, explains the mechanism of the limit suspension of the roadway item board, and puts forward the cutting item along the goaf retaining technology based on the research results. The main conclusions are as follows: 1) the paper is based on three typical item plate conditions.Through the establishment of the corresponding mechanical model, the calculation expressions of the limit suspension distance after the mining of the entry item are obtained: the hard rock roof roadway and the deep mine roadway roof respectively under the condition of the short distance coal seam caving through, the sensitivity analysis method is adopted in the case that the roof of the deep mine roadway is under the condition of the short distance coal seam caving.The influence factors of suspension distance of roadway under the condition of hard slabs are analyzed and evaluated. The results show that the width of plastic zone has the greatest influence on the distance of suspension, followed by the width of roadway, ultimate tensile strength, supporting strength and anchoring strength.Layer thickness, and finally determine the mechanical performance index of item floor rock layer for mining depth. Finally, using FLAC3D numerical analysis software, the influence of support strength in roadway on the limit suspension distance of item slab in deep roadway is simulated, respectively.The influence of roadway side support strength on the limit suspension distance of short distance coal seam and the influence of coal wall strength on the limit suspension state of hard item plate roadway.The results show that the lateral roof suspension ability is affected for different supporting strength in roadway, and when the support strength reaches a certain value, the increase of support strength has little effect on the length of lateral suspended roof.Simply increasing the strength of coal wall has little effect on the lateral suspension of roadway slabs, and it will not obviously change the distribution of supporting pressure in the working face in the lateral and leading directions.The strength of roadway side support has a great influence on the suspension of roadway slabs, and there is a range of influence, compared with the length of suspended roof without roadway side support, the length of suspended roof is increased by about 50%.) based on the research results, two kinds of engineering applications are introduced.The harm of thick and hard bottom strata after mining is clarified, and the treatment method of roof stability control is introduced.Flexible adjustment of roadway width, roadway support strength, anchoring strength and other parameters.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD353

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