基于比较法消除巷道影响的三维电法超前探测技术

Three-dimensional electrical method advanced detection technology based on comparative method to eliminate the influence of roadway

为消除巷道对井下三维电法超前探测技术的影响,选用ANSYS有限元软件模拟井下三维电法超前探测的实际工作,以控制变量法为准则,建立4个模型进行对比,对模型进行网格划分、加载与求解;从等位面电位变化的角度进行分析,得到视电阻率受巷道影响出现先减小后增大的假异常现象,而后运用比较法得出的消除巷道影响的干扰公式进行校正,校正后符合无巷道干扰时的结果;最终将工程应用中的数据用此方法进行校正,进行基于不等式约束与圆滑约束双重约束最小二乘反演,通过立体可视化处理,得到煤矿顶底板地层电阻率三维数据体,结合工区资料,圈定顶板砂岩及底板三灰富水异常区,提高了矿井三维电法超前探测技术的精确度。

In order to eliminate the influence of roadway on underground 3D electric method advanced detection technology,ANSYS finite element software was used to simulate the actual working situation of 3D electric advance detection in underground.Based on the control variable method,four models were established for comparison,and meshing,loading and solving of the established models were carried out.From the perspective of the potential change of the isosurface,it is obtained that the apparent resistivity is affected by the roadway,and then the false anomaly phenomenon that first decreases and then increases.The interference formula to eliminate the influence of the roadway obtained by the comparison method is used for correction,and the corrected result is consistent with the result when there is no roadway interference.Finally,the data in the engineering application was corrected,and the least-squares inversion based on the inequality constraint and the round constraint was applied.The threedimensional visualization process was used to obtain the three-dimensional resistivity data volume of the top and bottom layers of the coal mines.Combined with the work area data,the top sand sandstone and bottom grey ash rich water anomalies are delineated,which improves the accuracy of the mine 3D electric advanced detection technology.