矿用聚焦双频激电法电场扫描探测方法

Focusing dual-frequency induced polarization on electric field scanning method in coal mine roadway

为实现煤矿巷道超前探测,提出了一种基于双频激电法和电场扫描探测理论的矿用聚焦双频激电法超前探测技术。基于共线点电流源的电力线方程理论,推导煤矿巷道探测电场边界电力线方程算法;提出电场扫描探测策略,分析了电场扫描探测的实际分辨率;基于电介质边界条件,根据巷道地质结构模型推导电力线偏移向量求解公式,分析了地质异常体对电力线的影响。理论计算表明:通过连续改变探测仪各通道电流强度,探测电场扫描分辨率理论上可任意设定,实际探测由实际地质工况条件选定;地质异常体的存在会影响电力线分布,板状体的厚度越大或者围岩与板状体之间的电阻率比值越大或者板状体倾角越大,则电力线偏移向量横坐标与纵坐标的绝对值越大;通过电场聚焦和偏转扫描探测,可确定异常体的直径和方位。

To achieve an advanced detection in coal mine roadway,a method called focusing dual-frequency induced polarization method based on dual-frequency induced polarization method and electric field scanning detection theory was proposed in this paper. Based on the theory of collinear point current source electric line equation,the detection electric field boundary electric line equations were established and the complete algorithm was derived. The electric field scanning detection strategy was proposed and the actual resolution of electric field scanning detection was analyzed with the boundary electric line equation. Based on dielectric boundary conditions theory,the offset vector of the electric line was derived according to the roadway geological structure model,and the influence of geological anomaly on the electric line was analyzed. Theoretical calculations show that the detection electric field scanning resolution can be set arbitrarily by continuously changing the current amplitude of different channel of the detector theoretically,but it is set according to actual detection conditions. The existence of geological anomalies will affect the distribution of electric line and the greater of a,ρ1/ ρ2and β（ β≥90°- α）,the larger the absolute value of the offset vector of electric line. The size and orientation of the geological anomalies could be calculated through electric field deflection and focusing canning detection.