Penetrating radar study of the collapse features in a Nantou earth slide, Central Taiwan

This paper shows that ground-penetrating radar is an indispensable tool to study the internal configuration of a slide mass. The georadar facies and sliding surface are easily recognizable on the GPR profiles. The study area in this paper had undergone at least two earth slides. The internal configuration of the slide mass details the mechanism of this mass movement. Ten georadar facies were observed on the GRP profiles. They are chaotic, contorted, disrupted, hummocky, lenticular, oblique, onlap, overlap, subparallel, and reflection-free. At the head or crown part of the slide mass, chaotic, contorted, disrupted, oblique, and onlap facies are dominant. At the toe part, contorted, oblique, onlap, ad reflection-free facies are most common. In the main body of the slide mass, chaotic, contorted, disrupted, hummocky, lenticular, overlap, and subparallel facies dominate. Chaotic, contorted, and disrupted facies exist throughout the slide mass. Chaotic facies indicates severe movement, including rotation. Contorted facies results from a checked gravity sliding, whether checked by friction or blockade. Disrupted facies is caused by extension from gravity sliding. Similar studies can be extended to other areas prone to earth slide, so preventive measures can be adopted to abate the landslide hazards