1999 Volume 9 Pages 9-14
On natural ground consisting of altered andesite lava and pyroclastic rock of the Neogene period of the Miocene epoch, two-dimensional resistivity method and VLF-EM survey were conducted in addition to seismic wave exploration using the refraction method - which is commonly used for. geological surveys in tunnels. Comparisons of the results of these surveys were made along with comparisons of these results with actual geological conditions found through pilot boring.
As a result, geological conditions which were noto clear with only the results of seismic wave exploration using the refraction method could be further elucidated by the other two method. It was also confirmed that the differences in geological conditions within the natural ground, such as the physical and mechanical properties of bedrock and subterranean water conditions, were well refracted in the contrast of the resistivity and seismic wave velocity in the natural ground. It was also through that different geological conditions within the natural ground were probably caused by mineral composition variations due to differences in the extent of past alteretions.
