Comparison between dipole-dipole and pole-dipole arrays in delineation of subsurface weak zones using 2D electrical imaging technique in Al-Anbar University, Western Iraq

Abstract EN

The presence of natural voids and fractures (weak zones) in subsurface gypsiferous soil and gypsum, within the University of Al-Anbar, western Iraq.

It causes a harsher problem for civil engineering projects.

Electrical resistivity technique is applied as an economic decipher for investigation underground weak zones.

The inverse models of the Dipole-dipole and Pole-dipole arrays with aspacing of 2 m and an n-factor of 6 clearly show that the resistivity contrast between the anomalous part of the weak zone and the background.

The maximum thickness and shape are well defined from 2D imaging with Dipole-dipole array, the maximum thickness ranges between 9.5 to 11.5 m.

It is concluded that the 2D imaging survey is a useful technique and more effective for determining and mapping subsurface weak zones (voids, fracture and cavities), when taken in consideration using the suitable a-spacing and n-factor for each electrode array, especially with the Dipole-dipole array which provided the best imaging of the