矩形大定源回线TEM法全区视电阻率在煤田采空区勘探中的应用  

Application of large rectangular loop source TEM all-time apparent resistivity on colliery goaf exploration

作　　者：韩自强[1,2] 刘涛[2] 欧阳进[2] 罗姣[2] 

机构地区：[1]招商局重庆交通科研设计院有限公司,重庆400067 [2]长安大学地质工程与测绘学院,西安710054

出　　处：《地球物理学进展》2015年第1期343-349,共7页Progress in Geophysics

摘　　要：大定源回线TEM法在煤田采空区勘探中发挥着重要作用.利用偶极子合成回线源方式和二分法计算大定源回线TEM全区视电阻率时,误差函数计算十分耗时.研究发现用自变量复杂化的双曲正切函数近似误差函数,不仅计算速度快,而且精度满足要求,方便了大量实测数据快速全区视电阻率计算.理论模型计算结果验证了该方法的正确性.对实测采空区大定源回线TEM数据进行全区视电阻率处理,结果基本消除晚期视电阻率存在的"边界效应",在早期道不存在晚期视电阻率假高值,接近地表真实电阻率,对近地表局部异常有较好反映,对探测埋深较浅的积水小煤窑具有重要意义.Large loop source TEM method has played an important role in colliery goaf exploration.When using the method of dipole synthesis loop source and bisection method to calculate TEM all-time apparent resistivity,calculation of error function is very time-consuming.It is found that by hyperbolic tangent function with complicated argument to approximate error function,not only the calculation speed is fast,but also being to meet the accuracy requirements.So it is convenient to quickly calculate all-time apparent resistivity of large number of measured data.The results of the theoretical model verified the correctness of the method.The measured data of large rectangular loop source TEM in goaf is processed.Results not only weaken the border effect of late-apparent resistivity,but also have no false high values of late-apparent resistivity and more close to true resistivity of earth surface.All-time apparent resistivity has much better reflection of local anomaly in earth surface and has important meaning to explore small colliery goaf filled water in earth surface.

关 键 词：采空区 TEM 全区视电阻率 边界效应 

分 类 号：P631.84[天文地球—地质矿产勘探]