新街矿区3-1煤层开采对斜井管片结构影响的数值分析

发布时间：2018-03-17 17:40

本文选题：TBM工法　切入点：煤矿斜井　出处：《北京交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：TBM工法已经广泛应用于国内外各个领域的隧道建设中,技术理论成熟,施工经验丰富。但是,以TBM工法为基础建立的主、副运输斜井应用于煤矿领域,在国内尚属首次。本文依托内蒙古新街矿区(一井)斜井结构,研究TBM工法应用于煤矿建设领域的技术问题。新街矿区煤田由于工程所处地质情况复杂,其穿过某含水层厚度平均达到327.56m,且含水层透水性良好,故此斜井采用TBM(隧道掘进机)法开挖和管片拼装结构支护,斜井斜长6558m、倾角6。、厚度350mm,落底于3-1可采煤层的底板,与煤田中部的大巷连接。为了最大限度地进行煤层开采并控制对斜井结构的不利影响,需要估算合理的斜井保护煤柱尺寸。经验公式法只笼统地涉及煤层的几何参数和力学性质,而数值模拟则可以同时考虑煤层、岩层、斜井结构的几何特征和力学特征。本文针对地层-斜井的相对位置关系,采用以有限差分法为基本思想的FLAC3D软件计算分析。主要研究工作和取得的成果如下： 1.以二维固体力学模型为基础,在模型几何关系不变的情况下,保护煤柱宽度变化对管片影响最大,其次为岩层弹性模量变化,岩层粘聚力和摩擦角变化影响很小；而在其他参数不变的情况下,斜井底板距煤层越高,对管片的影响越小。以改变保护煤柱弹性模量大小和加固范围作为预加固措施,随着模量大小和加固范围的提高,斜井管片的轴力、弯矩均显著减小。 2.以三维固体力学模型为基础,随着保护煤柱宽度增加,管片所受的最大轴力、弯矩递减,但保护煤柱宽度增大到一定程度后,轴力、弯矩值将会稳定在一个范围内。岩石移动角变化对管片受力影响很小,对管片位移影响较大,随着岩石移动角增大,管片最大位移值呈先缓慢增大,后快速增大。 3.考虑地下水作用的流固耦合模型表明,渗流作用对管片的受力和位移更为不利；且地下水渗流时间越长对管片的位移影响越大,因此在实际工程中需要控制地下水的渗流影响。 4.根据“等效轴向刚度模型”理论公式及新街煤矿的实际参数,计算得到了管片纵向连接螺栓的弹性、塑性及破坏状态的临界曲率半径。根据FLAC3D计算结果,单纯的煤层开采对斜井纵向不均匀位移影响较小；但斜井周围发生局部渗流时,则会显著降低位移曲线的曲率半径,使斜井纵向螺栓达到塑性工作状态。
[Abstract]:TBM method has been widely used in tunnel construction in various fields at home and abroad. The technical theory is mature and the construction experience is rich. However, the main and secondary transportation inclined wells based on TBM method are applied to the coal mine field. It is the first time in China. Based on the inclined well structure of Xinjie mining area in Inner Mongolia, this paper studies the technical problems of the application of TBM method in the field of coal mine construction. Due to the complex geological conditions of the coal field in Xinjie mining area, the thickness of the coal field passing through an aquifer is 327.56 m on average, and the aquifer permeability is good. Therefore, the inclined shaft is excavated by TBM method and supported by the segment assembly structure. The inclined shaft is 6558 m long, with a dip angle of 6.50 mm and a thickness of 350 mm. It falls to the floor of the 3-1 minable coal seam and is connected with the roadway in the middle of the coal field. In order to maximize the coal seam mining and control the adverse effects on the inclined shaft structure, it is necessary to estimate the reasonable size of the inclined shaft protection pillar. The empirical formula method only deals with the geometric parameters and mechanical properties of the coal seam in general. The geometric and mechanical characteristics of coal seam, rock formation and inclined well structure can be taken into account in numerical simulation. The calculation and analysis of FLAC3D software based on the finite difference method are adopted. The main research work and the results obtained are as follows:. 1. Based on the two-dimensional solid mechanics model, under the condition that the geometric relation of the model is invariant, the change of the width of the protection coal pillar has the greatest influence on the segment, the next is the change of the elastic modulus of the rock layer, and the change of the cohesive force and the friction angle of the rock layer is very small. However, the higher the floor spacing of inclined well, the smaller the influence on the pipe segment when other parameters are not changed. With the change of elastic modulus and reinforcement range of coal pillar as pre-reinforcement measures, the axial force and bending moment of inclined shaft pipe are significantly decreased with the increase of modulus and reinforcement range. 2. Based on the three-dimensional solid mechanics model, the maximum axial force and bending moment of the segment decrease with the increase of the width of the protecting coal pillar, but when the width of the protected coal pillar increases to a certain extent, the axial force and bending moment value will be stabilized in a certain range. The change of rock moving angle has little effect on the stress of the segment and a great influence on the segment displacement. With the increase of the rock moving angle, the maximum displacement value of the segment increases slowly at first and then increases rapidly. 3. The fluid-solid coupling model considering the effect of groundwater shows that the seepage action is more unfavorable to the stress and displacement of the segment, and the longer the groundwater seepage time, the greater the influence on the displacement of the segment. Therefore, it is necessary to control the influence of groundwater seepage in practical engineering. 4.According to the theoretical formula of "equivalent axial stiffness model" and the actual parameters of Xinjie Coal Mine, the elastic, plastic and critical curvature radius of segment longitudinal connection bolt is calculated. According to the FLAC3D calculation results, Simple coal seam mining has little effect on longitudinal uneven displacement of inclined well, but when local seepage occurs around inclined well, the curvature radius of displacement curve will be significantly reduced, and the longitudinal bolt of inclined shaft will reach the plastic working state.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD82;TD32

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