Proceedings of the Korean Geotechical Society Conference (한국지반공학회:학술대회논문집)
- 2005.03a
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- Pages.376-383
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- 2005
Application of Geophysical Methods to Cavity Detection at the Ground Subsidence Area
물리탐사 기술의 지반침하지역 공동탐지 적용성 연구
- Kim, Chang-Ryol (Korea Institute of Geoscience and Mineral Resources) ;
- Kim, Jung-Ho (Korea Institute of Geoscience and Mineral Resources) ;
- Park, Young-Soo (Korea Institute of Geoscience and Mineral Resources) ;
- Park, Sam-Gyu (Korea Institute of Geoscience and Mineral Resources) ;
- Yi, Myeong-Jong (Korea Institute of Geoscience and Mineral Resources) ;
- Son, Jeong-Sul (Korea Institute of Geoscience and Mineral Resources) ;
- Lim, Heong-Rae (Korea Institute of Geoscience and Mineral Resources) ;
- Jeong, Ji-Min (Korea Institute of Geoscience and Mineral Resources)
- 김창렬 (한국지질자원연구원) ;
- 김정호 (한국지질자원연구원) ;
- 박영수 (한국지질자원연구원) ;
- 박삼규 (한국지질자원연구원) ;
- 이명종 (한국지질자원연구원) ;
- 손정술 (한국지질자원연구원) ;
- 임형래 (한국지질자원연구원) ;
- 정지민 (한국지질자원연구원)
- Published : 2005.03.25
Abstract
In this study, we conducted geophysical investigations for the organization of integrated geophysical methods to detect underground cavities of ground subsidence area at the field test site, located at Yongweol-ri, Muan-gun. We examined the applicability of geophysical methods such as electrical resistivity, electromagnetic, and microgravity to cavity detection with the aid of borehole survey results. Underground cavities are widely present within the limestone bedrock overlain by the alluvial deposits in the area of the test site where the ground subsidences have occurred in the past. The limestone cavities are mostly filled with groundwater and clays in the test site. Thus, cavities have low electrical resistivity and density compared to the surrounding host bedrock. The results of the study have shown that the zones of low resistivity and density correspond to the zones of the cavities identified in the boreholes at the site, and that the geophysical methods used are very effective to detect underground cavities. Furthermore, we could map the distribution of cavities more precisely with the test results incorporated from the various geophysical methods. It is also important to notice that the microgravity method is a very promising tool since it has rarely used for the cavity detection in korea. Beyond the investigation of underground cavities, the geophysical methods are required to provide useful information for the reinforcement design for the ground subsidence areas. It is, therefore, necessary to develop integrated geophysical technique incorporating different geophysical methods to precisely map underground cavities and image the subsurface of the ground subsidence areas.