采动承压水共同作用下煤矿底板突水演化特征试验研究

发布时间：2018-03-18 10:10

本文选题：流固耦合　切入点：底板突水　出处：《山东科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：矿井突水水害一直是我国煤矿安全开采面临的一大难题,随着采深增加和开采强度的不断增大,矿山开采所面临的环境更加复杂,矿井水害问题也日趋严重。本文就深部开采所处的高地应力和承压水等所处的复杂环境,通过理论推导、软件模拟、相似材料模拟试验等方法对采动承压水共同作用下煤矿底板突水演化特征进行了基础试验研究。本文参考前人的研究成果,推导裂纹初裂强度判据公式,揭示底板突水的动态机理;基于底板岩体裂隙的产生机理,通过理论推导,得出矿压作用下煤层底板破坏深度的计算公式,在此基础上,建立在高承压水作用下的底板破坏力学模型,分析得到应力分量式的计算公式。为了研究渗流场与应力场共同作用下,受高水压的破坏带和煤层底板破坏带能否沟通,以及高压底板破坏和突水通道形成、演化过程中的特征规律,运用COMSOL软件进行数值模拟,探究底板突水的发生与隔水层性质、水压等因素的对应关系。结合对渗流速度场、应力场、位移场、破坏深度、渗流压力场及流速分布在不同水压、隔水层性质因素影响下的分析对比,得出:承压水水压越大,渗流速度越大,底板位移变化量和破坏深度越大;隔水层厚度越大,底板承压水渗流速度越大,位移变化量及底板破坏深度越大,更易发生突水。综合深部地质构造力学环境以及相似材料渗流性等因素影响,研制了以凡士林、石蜡做为胶结剂,碳酸钙、河沙做为骨料,抗磨液压油做为调节剂的新型流固耦合相似模拟材料;建立承压水影响下的深部开采物理模型,探究采动煤层底板煤岩体应力及渗流变化规律,分析得出:岩体渗透性在采动煤层的底板周期性变化下显示出区域性、时间性;底板高渗透区分布具有不均匀性,首先产生于开切眼下方;远离采场影响范围岩体渗透性变化具有滞后性。
[Abstract]:Mine water inrush is always a difficult problem in the safe mining of coal mine in China. With the increase of mining depth and the increasing of mining intensity, the environment of mining is more complex. The problem of mine water damage is becoming more and more serious. In this paper, the complex environment of high ground stress and confined water in deep mining is deduced by theory and simulated by software. The basic experimental study on the evolution characteristics of water inrush in coal mine floor under the action of mining pressure and water is carried out by similar material simulation test. In this paper, the criterion formula of crack initial crack strength is derived with reference to the previous research results. The dynamic mechanism of floor water inrush is revealed, and the formula for calculating the depth of failure of coal seam floor under the action of mine pressure is obtained by theoretical derivation based on the formation mechanism of floor rock cranny, and on the basis of which, In order to study whether the failure zone under high water pressure can communicate with the failure zone of coal seam floor under the combined action of seepage field and stress field, a failure model of bottom plate under the action of high pressure water is established, and the formula of stress component is obtained by analyzing the model. As well as the characteristic law in the process of formation and evolution of high pressure bottom plate failure and water inrush passage, using COMSOL software to carry out numerical simulation, to probe into the corresponding relation between the occurrence of water inrush of bottom plate and the property of water barrier layer, water pressure and so on, combining with the seepage velocity field, The stress field, displacement field, failure depth, seepage pressure field and velocity distribution are analyzed and compared under the influence of different water pressure and the property of water barrier. It is concluded that the greater the water pressure of confined water, the greater the seepage velocity. The greater the thickness of the diaphragm, the greater the seepage velocity, the greater the displacement change and the deeper the failure depth of the bottom plate, the greater the displacement and the depth of the damage, the greater the thickness of the diaphragm layer, the greater the seepage velocity of the bottom plate pressure water. Water inrush is more likely to occur. Taking into account the influence of factors such as the mechanical environment of deep geological structures and the seepage properties of similar materials, Vaseline, paraffin as cementing agent, calcium carbonate and river sand as aggregates have been developed. A new type of fluid-solid coupling simulation material with antiwear hydraulic oil as regulator is established, the physical model of deep mining under the influence of confined water is established, and the law of stress and seepage of coal and rock mass in mining seam floor is studied. The analysis shows that the rock permeability shows regional and temporal characteristics under the periodic changes of the floor of the mining seam, and the distribution of the high permeability area of the floor is uneven, which first occurs under the open hole. The change of rock permeability away from the influence range of stope has hysteresis.
【学位授予单位】：山东科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD745.2

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