深井大断面沿空留巷底板裂隙分形特征动态演化规律试验研究

发布时间：2018-12-29 19:14

【摘要】：深井大断面沿空留巷常见严重底鼓问题,为更好揭示底鼓机理,利用自行研制的两向四面加载试验装置,结合顾桥矿1115(1)工作面轨道顺槽工程地质条件,采用相似材料模拟方法研究了深井大断面沿空留巷底板在掘进、一次采动、留巷和二次采动影响期间裂隙动态演化规律,并基于分形几何理论定量分析了分形维数变化规律及其与底鼓量的关系。研究结果表明,底板裂隙随着回采逐步发育、扩展、贯通,以剪切破坏的中高角度裂隙分布为主;底板裂隙分形维数逐渐增加,在顶板来压和留巷期间均有明显的升维现象;由于留巷上部基本顶的"回弹"现象,第二个工作面上覆岩层作用于煤体的载荷较小,导致在第二个工作面回采前期,底板裂隙分形维数增量较小;底鼓量和分形维数呈非线性正相关关系。通过对比现场实测底鼓量和试验底鼓量,发现二者能够较好吻合,验证模型试验结果的真实可靠。
[Abstract]:In order to better reveal the mechanism of bottom bulging, in order to better reveal the mechanism of bottom bulging, a test device with two directions and four sides is developed and combined with the engineering geological conditions of the track of 1115 (1) working face in Guqiao Coal Mine. Using similar material simulation method, the dynamic evolution law of fractures during excavation, primary mining, retaining roadway and secondary mining of bottom slab along goaf of large cross section of deep well is studied. Based on the theory of fractal geometry, the variation law of fractal dimension and the relation between fractal dimension and the volume of bottom drum are analyzed quantitatively. The results show that the bottom fissure develops gradually, expands and passes through along with the mining, and mainly distributes the fracture at the middle and high angle of shear failure, and the fractal dimension of the bottom fissure increases gradually, and there is obvious ascending dimension phenomenon in the period of roof pressure and roadway retention. Because of the "springback" phenomenon of the upper basic roof of the roadway, the load of the overlying strata acting on the coal body in the second working face is smaller, resulting in the small increment of fractal dimension of the floor fissure in the early mining period of the second working face. There is a nonlinear positive correlation between bottom drum and fractal dimension. By comparing the measured results with the experimental ones, it is found that both of them are in good agreement with each other and the results of the model tests are true and reliable.
【作者单位】：安徽理工大学能源与安全学院;煤矿安全高效开采省部共建教育部重点实验室;淮南国力液压装备有限公司;
【基金】：国家自然科学基金面上项目(No.51274010)~~
【分类号】：TD327.3

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