煤层采空区排水对斜井管片结构影响的数值模拟分析

发布时间：2018-04-25 08:45

本文选题：斜井 + 离散元　；参考：《北京交通大学》2017年硕士论文

【摘要】：新街矿区斜井井筒采用TBM工法进行施工。在煤矿系统,采用立井比较多,而采用斜井比较少。尤其斜井采用TBM法施工可以说在国内基本属于空白。对这一问题开展研究具有划时代的意义,它对于我国煤矿建设技术是一场革命,为煤矿安全、高效生产具有极其重要的社会、经济、现实意义。本文依托新街矿区煤层开采设计,重点研究由于地下水的存在对斜井管片结构造成的不利影响。以数值模拟为主要研究方法,分别采用UDEC离散元软件和FLAC3D有限差分软件进行二维和三维数值模拟。主要分析了煤层采空区排水边界条件的变化对斜井管片结构内力和位移产生的影响。用UDEC软件进行二维模拟分析时,主要考虑了岩体节理开度和煤层采空区排水边界水压力条件的变化对斜井管片结构内力和位移的影响;用FLAC3D软件进行二维和三维模拟时,主要考虑了煤层采空区节点排水量和煤层采空区排水边界水压力条件的变化对斜井管片结构内力和位移的影响。主要研究工作和取得的成果如下:(1)开挖平衡与排水平衡模拟结果对比可以发现,采空区排水使管片结构内力相对于煤层开采结束时有所增大。且管片结构最大轴力均出现在左帮偏下,最大弯矩则有从左帮向右帮移动的趋势。(2)煤层采空区排水会对管片结构位移尤其是竖向位移产生影响,且增加幅度较大。(3)UDEC二维模拟结果显示,岩层的节理开度越大,采空区排水量也越大,对管片结构位移和内力的影响就越大。(4)FLAC3D二维模拟结果显示,煤层采空区单节点排水量越大,对管片结构的内力和位移影响也越大。(5)煤层采空区排水边界水压力对管片结构内力分布形态的影响不大;随着排水边界设置压力的增大,管片结构的轴力和弯矩都有所减小,但变化量不大。(6)FLAC3D三维模拟结果与二维模拟结果对比可以发现,管片结构内力和位移在三维模拟结果情形下都较二维模拟结果略小,但变化规律基本一致。
[Abstract]:The inclined shaft of Xinjie mining area is constructed by TBM method. In coal mine system, there are more vertical wells and less inclined wells. Especially the inclined well construction by TBM method can be said to be basically blank in our country. The research on this problem is of epoch-making significance. It is a revolution for the construction technology of coal mines in China, and has extremely important social, economic and practical significance for the safety and efficient production of coal mines. Based on the mining design of coal seam in Xinjie mining area, this paper focuses on the adverse effect of groundwater on the pipe structure of inclined shaft. Using UDEC discrete element software and FLAC3D finite difference software as the main research methods, two-dimensional and three-dimensional numerical simulations are carried out. The influence of drainage boundary condition in goaf on internal force and displacement of inclined shaft segment structure is analyzed. The influence of rock joint opening and drainage boundary water pressure on the internal force and displacement of inclined shaft segment structure is mainly considered when UDEC software is used to simulate the rock mass joint and the drainage boundary water pressure condition in goaf of coal seam, and when FLAC3D software is used to carry out 2D and 3D simulation, the influence of rock mass joint opening and drainage boundary water pressure condition on the internal force and displacement of inclined shaft segment structure is considered. The influence of the displacement of the node in the goaf of coal seam and the water pressure condition of the drainage boundary in the goaf on the internal force and displacement of the pipe structure of inclined shaft is considered. The main research work and the results obtained are as follows: (1) comparing the simulation results of excavation balance and drainage balance, it can be found that the drainage in goaf makes the internal force of segment structure increase relative to the end of coal seam mining. The maximum axial force of segment structure appears under the left side, and the maximum bending moment moves from the left side to the right side. The drainage of goaf in coal seam will affect the displacement of segment structure, especially the vertical displacement. The results of 2D simulation of UDEC show that the larger the joint degree of rock layer, the greater the displacement of goaf, the greater the influence on the displacement and internal force of segment structure. The result of 2D simulation shows that the displacement of single node in goaf of coal seam is larger, and the displacement of single node in goaf of coal seam is larger than that of UDEC, and the effect on the displacement of segment structure and internal force is greater. The greater the influence on the internal force and displacement of the segment structure, the greater the influence of the drainage boundary water pressure on the distribution of the internal force of the segment structure in the goaf of coal seam, and the axial force and bending moment of the segment structure decrease with the increase of the drainage boundary setting pressure. However, comparing the results of 3D simulation and 2D simulation, it can be found that the internal forces and displacements of segment structures are smaller than those of 2D simulation results, but the variation law is basically the same.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD74

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