ZZ Resistivity Imaging Pty. Ltd.
There are other cases in which void detection could be difficult to use; for instance, when the void is saturated with water after heavy rain. This case study is a surface resistivity survey aimed at detecting buried mine shafts. After allocating main mine shaft chambers, the circled zone under question was hypothesized to be a void as well due to the heavy raining before the survey started. Further drilling validated with the previous deduction.
This survey is aimed at finding voids for construction safety purposes, as the figure below shows, 32 and 20 electrodes were placed into two boreholes, respectively. The inversion image found that the low resistivity areas beside the boreholes were likely to be karst caves. Later site investigation coincided with the inversion result.