Geoelectrical exploration of solution cavities at the Khao Laem damsite, Western Thailand

Abstract

Geophysical investigations including resistivity profiling, self potential survey and cross-hole-fan shooting seismic survey were carried out on a damsite to assess the applicability of geophysical techniques to explore solution cavities in limestone terrain. Electrical resistivity profiling was done using conventional Schlumberger, Wenner, half-Schlumberger and half-Wenner configurations. The results of geophysical surveys are compared with actual geological conditions obtained from tunnels. It is found that resistivity profiling with half-Schlumberger configuration gives the best results and shows good correlation with actual location of karstic features below the profile line.