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.

Keywords

• two and three dimensional electrical resistivity survey;
• karst area;
• limestone cavities;
• ground subsidence

• $2{\sim}3$차원 전기비저항탐사;
• 카르스트 지역;
• 석회암 공동;
• 지반침하;

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References

1. Kim, C. R., Kim, J. H., Park, S. G., Park, Y. S., Yi, M. J., Son, J. S., and Rim, H. R., 2006, Application of geophysical methods to cavity detection at ground subsidence area in karst, Mulli-Tamsa, 9(4), 271-278
2. Kim, J. H., Yi, M. J., Hwang, S. H., Song, Y. S., Cho, S. H., and Lee, S. K., 2003, Application of integrated geophysical methods to investigate the cause of ground subsidence of a high civilized area, Geosystem Engineering, 6(3), 74-80 https://doi.org/10.1080/12269328.2003.10541208
3. Park, S. G., Kim, C. R., Son, J. S., Kim, J. H., Yi, M. J., and Cho, S. J., 2006, Detection of limesillicate cavities by 3-D electrical resistivity survey, Economic Environmental Geology, 39(5), 597-605
4. Yi, M. J., Kim, J. H., and Chung, S. H., 2003, Enhancing the resolving power of least-squares inversion with active constraint balancing, Geophysics, 68, 931-941 https://doi.org/10.1190/1.1581045
5. Zhou, W. F., Beck, B. F., and Adams, A. L., 2002, Effective electrode array in mapping karst hazards in electrical resistivity tomography, Environmental Geology, 42, 922-928 https://doi.org/10.1007/s00254-002-0594-z