The three-year mapping and monitoring of underground cavity expansion with 2D resistivity survey: What has revealed?

摘要

Dissolution of near-surface salt domes appears to underlie the severe geotechnical and environmental problems in the Northeastern Thailand. Such salt dissolution increases not only a problem of salinity in soil and groundwater but also a problem of underground cavity. Thus this study aimed to apply a 2D resistivity survey for mapping and monitoring cavity expansion. A resistivity profile was conducted in the area nearby the sinkhole surface expression. A survey result indicated that the 2D resistivity survey could be used as a basic tool for identifying the near-surface underground cavity. An anomalous zone of the underground cavity could be distinguished as a low, 0.3 to 1.0 Ohm-meters, resistivity zone surrounded by a higher background resistivity. A cavity image appears as lateral and vertical anomalies. Result from three repeatedly measurement of apparent resistivity data that were acquired at the same month from different years was found to be useful for a determination of underground deformation through time.