矿井涌水量渗透系数构造分形优化研究

Study on optimization of permeability coefficient of structural fractal for mine water inflow

精准的水文地质参数在矿井涌水量预测中起到了极为关键的作用,其中渗透系数是水文地质中最常用的参数,不仅是含水层富水程度评价的重要指标,更是矿井涌水量预计、信息融合突水预测、岩体稳定性评价等定量计算的重要指标。为提高矿井涌水量的预测精度,采用分形理论,以分维数中的容量维为基本特征量,以赵庄二号井作为研究对象,通过选用网格覆盖法定量评价赵庄二号井矿井构造的复杂性,给予断层和褶皱不同的权重分形维数,并优化构造分形维数,得出修正公式。在此基础上,运用相关分析法,发现构造复杂程度与抽水试验所得渗透系数呈正相关关系,并对“大井法”的经验公式中的渗透系数取值进行了优化。研究结果表明:定量评价了赵庄二号井的构造复杂程度,计算出赵庄二号井全区的容量值为1.1665,表明赵庄二号井内构造相对复杂,从全区构造网络容量维叠加图中可以看出,区内构造复杂程度具有明显的不均一性;将优化结果运用到赵庄二号井2309工作面“大井法”涌水量预测过程中,误差从42.5%降到7.8%,“大井法”采用优化后的渗透系数进行矿井涌水量预计极大提高了准确率;将分形理论中的容量维引入煤矿构造复杂程度的评价中,实现了构造复杂程度定量的评价及渗透系数优化,为水文地质参数较少的矿区预测矿井涌水量提供了一种较为便捷的方法。

Accurate hydrogeological parameters have played a crucial role in the prediction of mine gushing water.Permeability coefficient is the most commonly used parameter in hydrogeology.It is not only an important indicator for evaluating the richness of aquifer water,but also an important indicator for quantitative calculations such as mine gushing water forecast,information fusion water inrush forecast,and rock mass stability evaluation.In order to improve the prediction accuracy of water inflow,the fractal theory was used,and the capacity di⁃mension in the fractal dimension was taken as the basic feature quantity.The Zhaozhuang No.2 Mine was used as the research area.The complexity of the mine structure of Zhaozhuang No.2 Mine was quantitatively evaluated by grid cover method.The weight fractal dimension of faults and folds was given,and the fractal dimension of structure was optimized to obtain the correction formula.On this basis,it is found that the structural complexity is positively correlated with the permeability coefficient obtained from the pumping test,so the values of the permeability coefficient in the“Large Well Wethod”empirical formula were optimized using the correlation analysis method.The results show that the structural complexity of the Zhaozhuang No.2 Mine is quantitatively evaluated,and the capacity value of the whole area of the study area was calculated to be 1.1665,indicating that the structure in the study area is relatively complex.It can be seen from the superposition map of the structural network capacity of the whole area that the structure in the area complexity has obvious inhomogeneities;Applying the optimization results to the prediction process of the“Large Well Method”water inflow in the No.2309 working face of Zha⁃ozhuang No.2 Mine,the error decreased from 42.5%to 7.8%.The“Large Well Method”used the optimized permeability coefficient to greatly improve accuracy rate of the mine water inflow;the capacity dimension in the fractal theory is introduced into the evaluation of the complexity of coal mine structure,and the quantitative evaluation of the structural complexity and the optimization of the permeability coef⁃ficient are realized,which is of great significance for the mine prevention and control of water and gas prevention in the study area.