复采工作面过空巷（群）顶板煤岩结构及控制

发布时间：2018-06-03 07:00

本文选题：复采 + 空巷　；参考：《太原理工大学》2017年硕士论文

【摘要】：回收遗留在采空区的优质资源、实现对旧采残煤的再次利用,对我国经济发展、资源可持续利用有重大意义。本文以圣华煤业3号煤1301复采工作面过空巷为研究背景,结合圣华煤业相关地质资料及物探手段对煤层赋存情况进行了分析统计,建立了基于顶板初次垮落和周期垮落两个过程的不同边界条件的顶板力学模型,计算并模拟出了顶板断裂形式。通过数值模拟手段,分析了空巷断面为65.64′mm和65.68′mm两种条件下顶板初次垮落步距及位置,以及遗留煤柱随复采工作面推进过程中应力分布与塑性区变化。针对顶板跨巷关键块B对复采工作面支架压力较大特点,提出了超前注浆充填工艺技术手段,并对其注浆参数进行了优化。其主要工作如下:(1)通过物探手段测得复采区遗留空巷宽度主要为2~10m,遗留煤柱宽度为4~20m;煤层赋存特征主要分为五种情况,分别是实体煤状态,顶煤完好、存在空巷状态,直接顶完好、顶煤冒落状态,底煤、顶煤全部采出、直接顶完好状态,直接顶冒落状态。(2)通过计算分析了3号煤基本顶厚度为4.66m,直接顶厚度为16.10m。根据弹性薄板理论,论证了将圣华煤业直接顶视为弹性薄板的可能性,为下文分析提供了一定的理论基础。(3)构建了采空区条件下“煤柱+顶板”系统力学模型,计算求得顶板中心挠度公式为,并求得“煤柱+顶板”系统条件下顶板最大挠度较小,复采区整体保持稳定。(4)构建了复采区工作面推进过程中初次垮落和周期垮落的顶板边界条件变化模型,初次垮落过程中顶板边界条件从四边固支、到两边简支两边固支、再到四边简支,所对应的顶板断裂形式为不对称的竖“O—X”型断裂形式;周期垮落过程可以将顶板边界条件看成从一边简支三边固支、到三边简支一边固支、再到四边简支的过程,所对应顶板断裂形式为不对称竖“半X—O”型断裂形式。与回采实体煤相比,遗留煤柱和空巷的存在使得顶板中间竖向裂纹出现在偏采空区侧。(5)通过FLAC3D数值模拟比较两种不同空巷断面随工作面推进对遗留煤柱、顶板的影响,有以下结论:空巷宽度较大时,煤柱塑性区范围增加较快,煤柱垂直应力的变化体现为煤柱应力分布从“马鞍型”、到“平台型”、再到“孤峰型”,并且在工作面向前推进的过程中,应力增长速率加快,尤其是在揭露空巷后,垂直应力变化强烈,煤柱出现提前失稳现象;空巷宽度的改变导致顶板断裂时关键块B长度与关键块C长度差值变化,且呈正相关性,即顶板发生断裂时,顶板中间竖向裂纹总是偏向于采空区后方。(6)建立了基于过空巷条件下的“跨空巷长关键块B”力学模型,计算求得支架工作阻力明显高于支架额定工作阻力,此时容易发生压架事故。为了工作面能够顺利过空巷,提出了对空巷或空巷冒落区采取超前注浆充填工艺。提出了充填承载层和截割层概念,理论计算出承载层厚度为4.5m,截割层厚度为2m;对承载层的强度要求为2MPa,对截割层的强度要求为1.5MPa。同时对注浆压力、注浆量、钻孔角度等参数进行了优化。
[Abstract]:It is of great significance to recycle the high quality resources left over in the goaf and realize the reuse of the old residual coal. It is of great significance to the economic development of our country and the sustainable utilization of resources. This paper has carried on the analysis of the coal seam occurrence with the related geological data and geophysical means of Shenghua coal industry 3 coal mine 1301 coal mining face as the research background. The roof mechanics model based on the different boundary conditions of the two processes of the first roof fall and the periodic caving is set up. The roof fracture form is calculated and simulated. Through numerical simulation, the initial caving distance and position of the roof under the two conditions of the 65.64 'mm and 65.68' mm are analyzed. The stress distribution and the plastic zone change in the process of surface propulsion. Aiming at the high pressure characteristics of the support of the key block B for the roof cross section, the advanced grouting technology is proposed and the grouting parameters are optimized. The main work is as follows: (1) the main work of the main work is that the width of the left lane width in the compound mining area is mainly 2~10m, The width of left coal pillar is 4~20m, and the characteristics of coal seam occurrence are mainly divided into five kinds, namely, solid coal state, good top coal and alley state, direct top and top coal caving state, bottom coal and top coal all mining, direct top condition and direct top caving state. (2) through calculation and analysis, the thickness of base top of No. 3 coal is 4.66M, direct top thickness. 16.10m. based on the elastic thin plate theory, the possibility that the direct roof of Shenghua coal industry is considered as an elastic thin plate is demonstrated. (3) a mechanical model of the coal pillar + roof system under the condition of goaf is constructed, and the formula of the roof central flexure is calculated and the "coal pillar + roof" system is obtained. The maximum deflection of the roof is small, and the overall recovery area remains stable. (4) the roof boundary condition change model of the first caving and periodic collapse in the process of the working face of the compound mining area is constructed, and the roof boundary conditions are fixed from four sides to the two sides of the simple support and then to the four side simply supported. The symmetrical vertical "O - X" type of fracture form; the process of periodic caving can be regarded as the roof boundary condition as a simple support from one side to three sides, to the three side simply supported on one side and then to the simple support of the four sides. The corresponding roof fracture form is the asymmetric vertical "half X O" type fracture. The vertical crack in the middle of the roof appears on the side of the partial goaf. (5) through the FLAC3D numerical simulation, the effects of the two different air roadway sections on the left coal pillar and the roof are compared. The following conclusion is that the plastic zone range of the coal pillar increases rapidly when the width of the empty lane is large, and the change of the vertical stress of the coal pillar is reflected in the stress distribution of the coal pillar. The saddle type, to the "platform type", and then to the "solitary peak type", and in the process of advancing front of the work, the stress growth rate is accelerated, especially after the opening of the alley, the vertical stress changes strongly and the coal pillar appears early instability, and the change of the width of the alley leads to the difference between the length of the key block B and the C length of the key block when the roof is broken, and In a positive correlation, when the roof breaks, the vertical crack in the middle roof always tends to the rear of the goaf. (6) a mechanical model of "B" based on the "cross lane length key block" is established under the condition of the over empty lane. The calculation results show that the working resistance of the support is obviously higher than the rated working resistance of the support. At this time, the pressure frame accident is easy to occur. Ahead of the empty alley, we put forward the pre grouting filling process for the empty alley or the empty lane. The concept of filling bearing layer and cutting layer was put forward. The thickness of the bearing layer was 4.5m, the thickness of the cutting layer was 2m; the strength of the bearing layer was 2MPa. The strength of the cutting layer was required for 1.5MPa. at the same time to grouting pressure, grouting amount and drilling angle. The parameters are optimized.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD327.2

【相似文献】