江宁台多孔垂向地电阻率观测试验

Experiment of the Porous Vertical Geo-resistivity Observation at Jiangning Station

为了提高地电阻率观测抑制地铁干扰的能力,江宁台新建了多孔垂向地电阻率观测。在观测中探讨完善了装置系数计算方法,解决了缺数问题,并通过比较同测区井下和垂向地电阻率观测数据,得出如下结论:(1)垂向观测由于布极方式较为特殊,其年变化幅度大于井下地电阻率观测同等极距;(2)与井下地电阻率观测相比,垂向地电阻率观测信噪比更高,具备更好的抗地铁干扰能力,以期为地电观测抗干扰的方法和技术应用提供基础;(3)垂向地电阻率观测建设中,可能需要重视电极的位置固定。

In order to improve the ability of geo-electrical resistivity observation to restrain subway interference,the porous vertical geo-electrical resistivity observation has been newly built in Jiangning station.In the process of observation,the calculation method of device coefficient is improved and the problem of missing number is solved.By comparing the observation data of deep-well and vertical geo-electrical resistivity observation data,we come to the conclusions that:(1)The annual variation amplitude of vertical observation is larger than that of underground earth resistivity observation with the same polar distance because of the special polar arrangement;(2)The signal-to-noise ratio of vertical geo-electrical resistivity observation is higher than that of deep-well geo-electrical resistivity,it has better anti-interference ability of metro,so as to provide the basis for the anti-interference methods and technology application of geo-electrical resistivity observation;(3)In the construction of vertical geo-electrical resistivity observation,it may be necessary to pay attention to the fixed position of electrode.