晋冀蒙交界及附近地区小极距井下地电阻率观测装置设计

Observation Scheme for Short Electrode Spacing Well Apparent Resistivity at the Vicinity of Shanxi-Hebei-Inner Mongolia Area

摘要:

为提升2022年北京冬奥会期间地电阻率测项的震情保障能力，将对晋冀蒙交界及附近区域的宝昌、集宁、阳原、大同、代县、临汾、通州和平谷8个台站在原有观测基础上增加具有全空间性质的小极距井下地电阻率观测。本文根据台站钻孔岩芯剖面和电测深数据反演测区水平层状电性结构，利用介质对地电阻率观测的影响系数方法，计算影响系数随极距和埋深的变化，选择合适的极距和埋深，使浅层介质对地电阻率观测的影响尽可能小，使目标层位对观测的贡献尽可能大，减少浅层介质对观测的影响。由此得出了各台站观测极距及埋深等装置系数，在此基础上完成了8个台站观测装置的方案设计。

Abstract:

In order to enhance earthquake prediction capacity of apparent resistivity during the Winter Olympics in 2022, short electrode spacing well apparent resistivity measurement will be added at 8 seismic stations(i.e., Baochang, Jining, Yangyuan, Datong, Daixian, Linfen, Tongzhou and Pinggu seismic stations), at the vicinity of Shanxi-Hebei-Inner Mongolia area. This paper combines the borehole core profile and electric sounding data to inverse the layered electric structures of these stations. Sensitivity coefficients of each layer versus electrode spacing and burning depth have been obtained. Then the appropriate electrode spacing and burning depths have been selected, making the effect from surface layer as small as possible and the contribution of the target horizon to observation as large as possible. Observation schemes of the 8 seismic stations have been eventually completed and have been approved by relevant departments. Construction of the stations will be launched in 2019.