Yang Zhenwei, Xu Junyi, Xu Zhaofeng, Chen Jiangfeng
Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo, 454000, China.
Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization, Jiaozuo, 454000, China.
Sci Rep. 2022 Jul 25;12(1):12658. doi: 10.1038/s41598-022-12656-w.
With the increasing depth of coal mining, the geological stress and structure becomes more and more complex. The elevation of No.8 coal floor significantly undulates in the studied coal mine. Even though a lot of boreholes have been drilled, it remains difficult to predict the spatial distribution features and it becomes challenging to plan the tunnel for the working face. Consequently, there has been a great loss of production in the coal mine, therefore, it is of great significance to study the prediction method for coal floor elevation of the working face. The surface spline function can be regarded as an infinite flat plate deformation in pure bending. The fluctuation of the coal floor can be considered to be the result of multi-period tectonic stress applied on the coal seam, so, the prediction of elevation of the coal floor with surface spline method is feasible. An advantage of surface spline method is that any order differentiable smooth surface can be obtained without regular known lattice and boundary derivatives. In the paper, the complete expression of surface spline function is derived, which is used to predict the elevation of No.8 coal floor of the coal mine. The results show that the trend of elevation of the coal floor can be extrapolated by known data, and the maximum error is 20 m, the minimum error is 0 m, and the error of 80% of the data is less than 3 m. The general trend of the coal floor has been predicted well. However, local peaks and valleys could not be predicted correctly, therefore, the first and second order derivative are projected to predict the peaks and valleys in the head of the tunneling.
随着煤矿开采深度的增加，地质应力和构造越来越复杂。在该研究煤矿中，8号煤层底板标高起伏显著。尽管已施工了大量钻孔，但仍难以预测其空间分布特征，给工作面巷道布置带来挑战。因此，该煤矿产量损失巨大，研究工作面煤层底板标高预测方法具有重要意义。曲面样条函数可视为无限大平板纯弯曲变形。煤层底板的起伏可认为是煤层受到多期构造应力作用的结果，所以，采用曲面样条法预测煤层底板标高是可行的。曲面样条法的一个优点是无需规则的已知网格和边界导数就能得到任意阶可微的光滑曲面。本文推导了曲面样条函数的完整表达式，并用于预测该煤矿8号煤层底板标高。结果表明，利用已知数据可外推煤层底板标高趋势，最大误差为20米，最小误差为0米，80%的数据误差小于3米。煤层底板的总体趋势预测良好。然而，局部的峰谷无法正确预测，因此，通过求一阶和二阶导数来预测巷道掘进头处的峰谷。
