巷道直流电阻率法超前探测三维数值模拟

针对巷道直流电阻率法超前探测的三维数值模拟，应用代数多重网格快速算法对二次场的有限差分问题进行求解。将均匀全空间板状体数值结果与解析解对比，最大误差不超过0.28%。模拟结果表明，巷道空腔对测量结果存在一定影响，采用比值曲线消除该影响，修正后的视电阻率极值与理论值误差为2.4%。进一步研究受旁侧影响的前方异常识别方法，可通过在不同巷道面进行定点源测量或掘进过程中的定点测量来识别旁侧影响，达到准确探测前方异常的目的。

3D numerical modeling of tunnel DC resistivity for in -advance detection

3D numerical modeling of tunnel DC resistivity for in-advance detection is carried out in this paper. A fast algebraic multi-grid solver is used to solve the finite difference problem of the second potential. Comparing the numerical solution to the analytical solution of a board model in homogeneous space, the relative error is under 0.28%. Modeling results show that the tunnel cavity itself has influence on the survey data, which could be corrected by ratio curve method. The relative error between the corrected apparent resistivity and the analytical one is 2.4%. Furthermore, a method for identification of the frond anomalies nfluenced by side anomalies is also studied. Modeling results show that the frond anomalies could be correctly identified by surveys on different surfaces of the tunnel or by surveys during the excavation.