地质雷达在华南某工地岩溶勘察中的应用效果分析

Application Effect Analysis of Ground Penetrating Radar in Karst Exploration of a Construction Site in South China

华南某岩溶工地准备进行超前钻勘察工作,由于场地详勘过程发现岩溶较发育,为查明近地表5 m范围内土洞、溶洞等不良地质体平面位置及顶底板埋深,采用地质雷达进行连续剖面测量。根据地质雷达勘察成果选择3个异常进行钻孔验证,3个验证孔均打到空洞或充填型溶洞,异常埋深与地质雷达异常深度位置基本一致,物探推测与钻孔验证结果基本吻合。通过勘察实例表明,在第四系覆盖层厚度较小或基岩裸露场地,利用地质雷达探测能够获得场地不良地质体发育情况。同时要注意,识别并排除干扰源才能对地质雷达资料做出正确推断解释。

Before advanced drilling and survey work is carried out in a karst construction site in South China,the ground penetrating radar is used to perform continuous profile measurements to find out the plane position of unfavorable geological bodies such as soil caves and karst caves within 5 meters of the surface and the buried depth of the roof and floor,due to the fact that karst is relatively developed in the course of detailed site survey,According to the results of ground penetrating radar(GPR)survey,3 anomalies are selected to be verified by drilling,and all the 3 verification holes are drilled into cavities or filled karst caves.The depth of the anomalies is basically consistent with the position of the GPR anomalies,the result of geophysical prospecting is basically consistent with that of drilling verification.In this paper,the exploration examples show that the development of bad geological bodies can be obtained by using GPR in the areas where the thickness of the quaternary overburden is small or where the bedrock is exposed,only by identifying and eliminating the jamming sources can we make correct inference and interpretation to the GPR data.