多年冻土层下煤层开采地表沉陷规律研究

发布时间：2018-05-13 11:19

本文选题：多年冻土层 + 大倾角煤层　；参考：《西安科技大学》2017年硕士论文

【摘要】：娘姆特煤矿首采区煤层属于大倾角煤层,地表赋存有20m-70m厚的多年冻土层。冻土的特殊性决定了工作面煤层开采后地表沉陷规律的特殊性。因此,研究多年冻土层下煤层开采的地表沉陷规律具有重要意义。本文以娘母特煤矿二采区为具体背景,采用理论分析、物理相似材料模拟实验和数值模拟相结合的研究方法,对多年冻土层下煤层开采后的地表沉陷规律进行研究。根据资料分析以及冻土力学实验得出矿区多年冻土层的物理力学参数。利用物理相似模拟以及数值模拟方法对地表多年冻土层下沉特征和多年冻土层的变形破断特征进行分析。研究表明多年冻土层下大倾角煤层开采后地表变形的下沉曲线呈非对称分布,最大下沉点偏向于埋藏较深煤层地表,最大下沉量达2.14m;地表多年冻土层与下覆岩层产生离层,最大离层量达1.35m;随着多年冻土层厚度的增加,地表下沉量逐渐减小,下沉范围逐渐增大,地表水平移动最大值逐渐减小,水平移动范围逐渐增大。通过理论公式计算研究得出多年冻土层挠曲变形下沉值为1.48m时发生初次破断,初次破断步距为291m;下沉挠度达到周期破断挠度0.11m时发生周期型破断,周期破断步距为85m。研究结果对多年冻土层下煤层开采地表损害控制具有重要意义。
[Abstract]:The coal seam in the first mining area of Niangmute coal mine belongs to the large dip coal seam, and the permafrost of 20m-70m thickness exists on the surface. The particularity of frozen soil determines the particularity of surface subsidence law after coal seam mining. Therefore, it is of great significance to study the surface subsidence law of coal seam mining under permafrost. Taking the second mining area of Niangmutie Coal Mine as the specific background, this paper studies the law of surface subsidence after mining coal seam under permafrost by means of theoretical analysis, physical similar material simulation experiment and numerical simulation. The physical and mechanical parameters of permafrost in mining area are obtained based on the analysis of data and the experiment of frozen soil mechanics. The subsidence characteristics of permafrost and the characteristics of deformation and fracture of permafrost are analyzed by physical similarity simulation and numerical simulation. The research shows that the subsidence curve of the surface deformation after mining the coal seam with large inclination under permafrost is asymmetrical, the maximum subsidence point is inclined to the surface of buried deep coal seam, and the maximum subsidence amount is 2.14m.The permafrost layer and the overlying rock layer are separated from each other. With the increase of permafrost thickness, the surface subsidence gradually decreases, the subsidence range increases, the maximum horizontal movement decreases, and the horizontal movement increases gradually. Through theoretical formula calculation and study, it is concluded that the first break occurs when the deflection subsidence value of permafrost is 1.48 m, the first break step distance is 291 m, and the periodic break occurs when the deflection reaches 0.11 m and the periodic break step distance is 85 m. The results are of great significance to control the surface damage of coal seam mining under permafrost.
【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】：TD327

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