Econ. Environ. Geol. 2001; 34(2): 193-204
Published online April 30, 2001
© THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY
Surface Geophysical Investigations of a Slope-failure Terrane at Wiri, Andong, Korea
Correspondence to : Ji-Soo Kim
Abstract
A geophysical survey was undertaken at Wiri area, Andong, to delineate subsurface structure and reveal the fault zone nearby which heaving of road and subsidence of slope occurred in 1997, especially in the heavy rainy season. Electrical resistivity methods of dipole-dipole array profiling and Schlumberger array sounding and seismic methods of refraction and reflection were performed for the mapping of clay layer, which was interpreted to be the major factor among the reasons of slope deformation. The clay layer was characterized by lower electrical resistivities (<100 Ω ? m) and lower seismic velocities (<400 m/s), respectively. The results of electrical and seismic surveys showed that subsidence of slope was probably associated with sliding of wet clay on 18SW/NNW trending fault
plane, while heaving of road was probably caused by upward movement of the wet clay through subvertical NNE trending fault.
Keywords surface geophysical survey; electrical resistivity; seismic velocity; slope-failure terrane; fault
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Econ. Environ. Geol. 2001; 34(2): 193-204
Published online April 30, 2001
Copyright © THE KOREAN SOCIETY OF ECONOMIC AND ENVIRONMENTAL GEOLOGY.
Surface Geophysical Investigations of a Slope-failure Terrane at Wiri, Andong, Korea
Ji-Soo Kim1*, Soo-Hyung Han1, and Gyo-Cheol Jeong2
1Department of Earth and Environmental Sciences, Chungbuk National University, Chongju, Korea, 361-763
2Department of Earth and Environmental Sciences, Andong National University, Andong, Korea, 760-749
Correspondence to:
Ji-Soo Kim
Abstract
A geophysical survey was undertaken at Wiri area, Andong, to delineate subsurface structure and reveal the fault zone nearby which heaving of road and subsidence of slope occurred in 1997, especially in the heavy rainy season. Electrical resistivity methods of dipole-dipole array profiling and Schlumberger array sounding and seismic methods of refraction and reflection were performed for the mapping of clay layer, which was interpreted to be the major factor among the reasons of slope deformation. The clay layer was characterized by lower electrical resistivities (<100 Ω ? m) and lower seismic velocities (<400 m/s), respectively. The results of electrical and seismic surveys showed that subsidence of slope was probably associated with sliding of wet clay on 18SW/NNW trending fault
plane, while heaving of road was probably caused by upward movement of the wet clay through subvertical NNE trending fault.
Keywords surface geophysical survey; electrical resistivity; seismic velocity; slope-failure terrane; fault
