Imaging Fractures beneath a Residential Complex Using Novel 3-D Electrical Resistivity Arrays

ABSTRACT Typical 3-D electrical resistivity tomography sampling schemes, which require a grid of electrode lines to be deployed, are limited by physical conditions of the area under study. New array techniques are needed to characterize the subsoil beneath anthropogenic or natural structures to define hazardous zones. Use of multiple L-shaped arrays overcome the need for a grid of electrodes by surrounding an area in a square of electrode lines; however, in some instances, the physical environment does not allow closure of a square of electrodes. An alternative array introduced in this investigation is termed the horseshoe array. The horseshoe array combines the L-shaped arrays with equatorial and minimum coupling arrays to overcome array closure problems. Three synthetic examples were investigated to establish the limitations of the horseshoe array, and to describe the geological conditions of the subsoil, e.g., building foundations and fractures. The first two examples represent two resistive cubes init...