海安台井下与地表地电观测对比实验研究

The contrast experimental study between the down-hole and surface about the geo-electric field and resistivity observation in Haian station

在海安地电观测台站对地表、井下地电观测进行了对比实验,分析研究了地表游散电流、金属管线、以及人工交/直电流对地表、井下地电观测的影响.研究表明:(1)在使用铅电极的情况下,井下地电观测的长期稳定性明显优于地表观测;垂直方向观测的抗干扰能力明显优于地表、井下水平方向观测;(2)与地表观测相比,井下地电观测能在一定程度上抑制地表直流电流、雷电、和金属管线类的影响;(3)地表直流电流对地电观测所产生的干扰影响远大于交流电流.

Contrast experiment between the down-hole and ground-surface observations of the geo-electrical field and resistivity has been performed at Hai’an seismic station of Jiangsu province, and the effects for the geo-electrical observation accuracy that are caused by the ground-surface stray current,artificial A.C./D.C.and metal pipe net are analyzed and studied.As a result,we have the following results：（1）In the case of lead electrode,the long-term stability of the down-hole geo-electrical observation is superior to that of the ground-surface,and the vertical anti-interference ability is better than that of surface and the underground horizontal direction;（2）Compared with surface observations,underground Geo-electric observation can inhibit the effect of surface current,lightning,and metal pipeline class to a certain extent;（3）The interference generated by the surface of direct current is far greater than that of the alternating current to Geo-electric observation.