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

  • Amina M. Salman Department of Geology, College of Science, Baghdad University, Baghdad, Iraq
  • Ali M. Abed Department of Applied Geology, College of Science, Al- Anbar University, Ramadi, Iraq
  • Jassim M. Thabit Department of Geology, College of Science, Baghdad University, Baghdad, Iraq
Keywords: Pole-dipole array, Dipole-dipole array, Cavity detection, Weak zone delineation, Injana Formation

Abstract

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
subsurface shape of the weak zones.

Published
2020-03-27
How to Cite
Salman, A. M., Abed, A. M., & Thabit, J. M. (2020). 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. Iraqi Journal of Science, 61(3), 567-576. https://doi.org/10.24996/ijs.2020.61.3.12
Section
Geology