Application of Resistivity Technique for Identifying Cavities Near Surface in Karst Area, Muan-gun, South of Korea

무안군 카르스트 지역의 지하공동 탐지를 위한 전기비저항 탐사 기술 적용

  • Farooq, Muhammad (Department of Mineral Resources and Energy Engineering, Chonbuk National University) ;
  • Park, Sam-Gyu (Geotechnical Engineering Division, KIGAM) ;
  • Song, Young-Soo (Department of Mineral Resources and Energy Engineering, Chonbuk National University) ;
  • Kim, Jung-Ho (Geotechnical Engineering Division, KIGAM)
  • ;
  • 박삼규 (한국지질자원연구원 지반안전연구부) ;
  • 송영수 (전북대학교 자원.에너지공학과) ;
  • 김정호 (한국지질자원연구원 지반안전연구부)
  • Published : 2008.11.30

Abstract

This study evaluates the usefulness and capability of surface electrical resistivity technique for identifying the weak zones or subsurface cavities in karst area with limestone formation. Weak zones or cavities near surface can be potentially dangerous and several problems are associated with collapse of roads or buildings accompanied by subsidence phenomena. In this paper, both two and three dimensional resistivity investigation were conducted to investigate subsidence along a road in Yongweol-ri, Muan-gun, South Korea. The results of the resistivity survey using dipole-dipole array provide a clear view of the weathered regolith, the distribution of weak zones or cavities and bedrock. Several low resistivity areas were identified and subsequent drilling led to the discovery of several weak zone or clay-filled underground cavities. The drilling results show excellent correlation with the resistivity images. It is illustrated, the ability of electrical technique to produce high resolution images of subsurface, which are useful for subsidence assessment. Also the results of this study have demonstrated that two and three dimensional electrical resistivity surveys are useful for delineating the subsidence area. Based on resistivity imaging, the map of hazardous zone has been developed.

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