浅埋煤层开采突水溃砂的颗粒流模拟研究

发布时间：2018-09-17 07:08

【摘要】：为研究浅埋煤层开采下突水溃砂的覆松散层渗透破坏、水砂耦合流动及突涌规律,指导预防突水溃砂灾害的发生提供依据,采用二维颗粒流软件PFC2D分别对上覆松散层渗透变形破坏、水砂混合流运移过程进行数值模拟研究,建立了浅埋煤层开采突水溃砂的数值模拟模型。结果表明:上覆松散含水层的初始水压力与裂隙通道的宽度对松散层的渗透变形破坏过程有较大影响。当含水层初始水压力增加时,裂隙处流体的流速、颗粒间的接触应力均明显增加,且呈现出非线性增长趋势;水砂混合流的突出时间以及突出速度与裂隙通道的倾角、粗糙度相关。同时根据水砂混合流的Y方向突出速度大小的波动变化规律,预测了2种可能存在的水砂突出类型;含水层的初始水压力影响突水溃砂的发生及运移过程,由此提出了通过疏放松散层水来预防突水溃砂灾害发生的方法。
[Abstract]:In order to study the seepage failure, coupled flow and surge of water and sand under shallow coal seam mining, and to guide the prevention of water bursting and sand bursting, the paper provides a basis for preventing the occurrence of water bursting and sand bursting. A numerical simulation model of water burst sand burst in shallow coal seam mining is established by using two-dimensional particle flow software PFC2D to simulate the seepage deformation failure and mixed flow migration process of overlying loose beds. The results show that the initial water pressure of the overlying loose aquifer and the width of the fissure channel have great influence on the seepage deformation and failure process of the loose layer. When the initial water pressure of the aquifer increases, the velocity of fluid and the contact stress between particles increase obviously, and show a nonlinear increasing trend, the outburst time of the mixed flow of water and sand, and the angle between the outburst velocity and the fissure channel, Roughness correlation. At the same time, two possible types of water-sand outburst are predicted according to the fluctuation law of Y direction outburst velocity of water-sand mixed flow, and the initial water pressure of aquifer affects the occurrence and migration of water-bursting sand. Therefore, the method of preventing water inrush and sand bursting by thinning loose layer water is put forward.
【作者单位】：中国矿业大学力学与建筑工程学院;中铁第五勘察设计院集团有限公司;
【基金】：国家自然科学基金(51134018) 国家重点基础研究发展计划(2011CB201201) 中央高校基本科研业务经费(2010YL07)
【分类号】：TD745;TD823

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