旧采残煤长壁开采煤柱应力分布及破坏规律研究

发布时间：2018-06-15 14:14

本文选题：残煤复采 + 蠕变试验　；参考：《太原理工大学》2017年硕士论文

【摘要】：上世纪八、九十年代,限于技术和装备条件不足,我国地方小煤矿曾长期采用刀柱式、巷柱式(高落式)等旧式采煤方法,回采率不到30%,导致大量的优质煤炭资源遗留于采空区内,造成极大的浪费。旧采残煤的再次开采利用,能充分利用宝贵的煤炭资源、对矿井可持续发展具有重要的现实意义。本文以晋煤集团圣华煤业3号煤层残煤复采为工程背景,在煤岩蠕变试验的基础上,运用正交试验设计法,研究了各开采因素对旧采区煤柱稳定性的影响规律;通过数值模拟,研究了复采工作面推进时不同稳定性煤柱的应力分布及破坏规律及在预充填条件下煤岩体的应力分布及破坏规律,为残煤长壁开采提供理论依据。主要工作如下:1、为研究开采因素对旧采区煤柱稳定性影响规律,进行了煤岩蠕变试验,比较了西原模型与西原加速模型对描述圣华煤业煤岩蠕变特性的适用性,得出了适于描述圣华煤业煤岩蠕变特性的本构模型,并对该本构模型的蠕变参数进行了辨识。2、利用蠕变试验结果对旧采区煤柱稳定性状态进行数值模拟。研究了煤柱宽度、巷道宽度、巷道高度等开采因素对煤柱核区率、煤柱中最大垂直应力、煤柱中最大剪切应力的影响。研究表明,对煤柱核区率影响最大的因素为自身煤柱宽度、巷道高度;对煤柱中最大垂直应力与最大剪切应力影响最大的因素为空巷宽度。建立了圣华煤业旧采区煤柱的核区率、最大垂直应力、最大剪切应力与各影响因素的数学模型。3、研究了复采工作面推进时应力场的变化规律与超前煤柱稳定性对复采工作面在推进时应力场变化规律的影响。研究表明:在复采工作面推进时,超前支承压力应力集中系数为2-3,应力峰值位于工作面前方煤柱或超前煤柱。当旧采区超前煤柱核区率为45%时,基本顶初次垮落步距为14m,基本顶超前断裂步距为17m;当旧采区超前煤柱核区率为70%时,基本顶初次垮落步距为16m,基本顶超前断裂步距为18m。4、分析了超高水材料预充填旧采区空巷对复采工作面的推进时应力场变化规律的影响。研究表明:预充填旧采区空巷后,在复采工作面推进时,应力峰值始终位于工作面前方煤岩,基本顶初次垮落步距为20m。与未充填相比,空巷预充填对工作面前方围岩与顶板稳定性控制起到了积极作用。
[Abstract]:In the eighties and nineties of the last century, limited to inadequate technical and equipment conditions, local small coal mines in China have long adopted old mining methods such as knife pillar type, roadway pillar type (high fall type) and so on. The recovery rate is less than 30, resulting in a large number of high quality coal resources left in the goaf, resulting in a great deal of waste. The remining and utilization of residual coal in old mining can make full use of valuable coal resources and have important practical significance for the sustainable development of mines. In this paper, the influence of mining factors on the stability of coal pillar in the old mining area is studied by using orthogonal design method based on the creep test of coal and rock, based on the engineering background of residual coal remining in Shenghua Coal Mine of Shanxi Coal Group, and the numerical simulation is carried out to study the influence of mining factors on the stability of coal pillar in the old mining area. This paper studies the stress distribution and failure law of different stability pillars and the stress distribution and failure law of coal and rock mass under pre-filling condition, which provides theoretical basis for long wall mining of residual coal. The main work is as follows: in order to study the influence of mining factors on the stability of coal pillar in old mining area, the creep tests of coal and rock are carried out, and the applicability of Xiyuan model and Xiyuan accelerated model to describe the creep characteristics of coal and rock in San Hua coal industry is compared. A constitutive model suitable for describing the creep characteristics of coal and rock in San Hua coal industry is obtained, and the creep parameters of the constitutive model are identified. The creep test results are used to simulate the stability of coal pillar in the old mining area. The influence of mining factors such as the width of coal pillar and the height of roadway on the rate of coal pillar core the maximum vertical stress in the pillar and the maximum shear stress in the pillar are studied. The results show that the most important factors affecting the core area of coal pillar are the width of coal pillar and the height of roadway, and the maximum vertical stress and shear stress of coal pillar are the most important factors affecting the width of empty roadway. The nuclear area rate and maximum vertical stress of the coal pillar in the old coal mining area of the San Hua coal industry were established. The maximum shear stress and the mathematical model of influencing factors. 3. The variation law of stress field and the influence of the stability of leading coal pillar on the stress field of remining face are studied. The results show that the stress concentration factor of the leading support pressure is 2-3 and the peak value of the stress is located at the coal pillar or the leading pillar in front of the working face. When the rate of coal pillar core in the old mining area is 45, the first collapse step distance of the basic roof is 14 m, the walk distance of the basic top leading fault is 17 m, and when the coal pillar core rate is 70 m in the old mining area, The initial collapse step distance of the basic roof is 16 m and the basic top leading fault step distance is 18 m.4. The influence of the old goaf roadway pre-filled with ultra-high water material on the stress field variation law of the remining face is analyzed. The study shows that the peak stress is always located in the coal rock in front of the working face and the initial collapse distance of the basic roof is 20m after pre-filling of the old goaf roadway and when it is pushed forward in the remining face. Compared with the non-filling, the pre-filling in the empty roadway plays a positive role in controlling the stability of surrounding rock and roof in front of the face.
【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】：TD823.4

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