裸露岩溶区地下河管道综合地球物理方法探测研究

The Study of underground river course detection by integrated geophysical methods in bare karst area

本文选取桂林市海洋乡裸露岩溶区地下河管道分别进行了可控源音频大地电磁法、三极电测深法和充电法试验对比研究,其综合成果得到了钻探验证.试验研究表明,充电法对具有出口、进口或天窗的地下暗河定位追踪准确,效果明显.可控源音频大地电磁法探测深度大,横向分辨率高,对寻找深部构造破碎带具有独特的优势.三极测电深法受场地条件、高阻围岩和地形起伏影响较大,不能满足对地下暗河的定位要求.

In bare karst area, the comparative experimental study of Controlled Source Audio Magnetotelluric Method, three-pole electrical sounding and Mise-a-la-Masse method were carried out over the subterranean river in Hai Yang county, Guilin. The integrated results have been approved well by drilling. Experimental studies have shown that Mise-ada-Masse method can accurately position and track the underground river which has the outlet, inlet or underground river window. Controlled Source Audio Magnetotelluric Method has unique advantages to seek deep fracture zone due to its deeply probing depth and high lateral resolution. Three-pole electrical sounding was heavy affected by the site space and surrounding rock＇ s high- resistance as well as undulating terrain, couldn＇ t effectively locate the underground river.