装置和电极距对岩溶管道高密度电法响应特征的影响研究

Research on the effect of device and electrode distance on the characteristics of high-density resistivity method in karst pipeline

高密度电阻率法在岩溶区找水具有较好的效果,但其成像效果和工作效率易受装置和电极距的影响。为了提高岩溶区高密度电法找水的勘探效果,文章采用高密度电阻率法微测系统,利用铜柱体模拟地下岩溶管道,研究不同装置及电极距对高密度电法探测岩溶管道的影响。结果表明:矩形AMN装置和滚动MNB装置比α_2装置对异常的响应更灵敏,对确定异常体的顶部埋深优于α_2装置;而α_2装置对异常的定位及确定异常体的大小优于前二者;岩溶管道低阻异常体的高密度电阻率联合剖面法的响应特征为高阻正交点,利用该方法能精确地对异常体进行定位;电极距越小,分辨率越高,反演异常顶部埋深和横向宽度越接近真实异常,但反演异常投影中心越偏离真实异常。

The high-density resistivity method is effective in searching for groundwater in karst areas, but the device and electrode distance can affect the image quality and work efficiency. In order to improve the prospecting effect of this method on water exploration, the authors use a high-density micro-electrical measurement system and the copper cylinder model to simulate the underground karst pipelines, and examine the effect of the device and electrode distance on the characteristics of the resistivity method in karst pipelines. The results indicate that the rectangular AMN and the roiling MNB device is more sensitive than the c^2 device, the or2 device is superior to the rectangular AMN device and the rolling MNB device for locating the anomaly and determining the size of the abnormal body. The rectangular AMN device and rolling MNB device are better than the c^2 device for determining the top depth of the abnormal body. The response characteristics of the high density resistivity combined profiling method for the low resistivity anomaly body of karst pipelines are the high resistivity positive intersection, and the high density resistivity combined profiling method can precisely locate the abnormal body. The smaller the electrode distance, the higher the resolution, and the more close to the true anomaly in the inversion anomaly of the top depth and the lateral width, but the more deviated from the true anomaly in the inversion anomaly of the projective center.