超低频地质雷达在岩溶勘探中的应用研究

研究目的:高频及中低频地质雷达在工程质量检测及浅部岩溶、洞穴的探测中已得到广泛应用,但在勘察设计阶段的较深部(15～40 m)路基岩溶探测中需要采用更低频率地质雷达进行探测。通过对超低频雷达组合天线的应用研究,可采用改变组合频率实现某些特殊情况下大深度的岩溶探测,以弥补传导类电法勘探的不足。研究结论:超低频雷达组合频率在某些较厚覆盖层场地条件下可取代常规直流电法,由于地表坚硬或地形起伏较大所带来的应用能力不足,从而可提高路基岩溶勘探精度及效率。针对不同场地条件下的各种雷达空气回波干扰特征进行了分析并找到了较合理的处理方式,在实际应用中取得了较好的岩溶探测效果。

Study on Application of Ultra- low Frequency Ground Penetrating Radar in Karst Exploration

Research purposes: The high and middle-low frequency ground penetrating radars have been widely used in the testing engineering quality and detecting shallow karst and the karst cave,but detecting the deeper karst cave(15~40 meters) needs lower frequency ground penetrating radar in the stage of survey and design.The research on application of the combined antenna of the ultra-low frequency radar shows the ultra-low frequency radar can be used for detecting the deeper karst cave in some special cases by changing the combined frequency to make up the deficiency of the electrical prospecting. Research conclusions:The electrical prospecting method is poor in detecting in the hard ground or rugged terrain,so the method of ultra-low combined frequency ground penetrating radar could be substituted for the normal electrical prospecting in this condition,and it could improve the precision and efficiency in the exploration of karst roadbed.The jamming characteristic of different radar echoes under the different site conditions is analyzed and the rational method is found,achieving the good results in the practical application of karst cave exploration.