Application of 2D and 3D Electrical Resistivity Imaging Techniques for Site Investigation in Ramadi City, Western Iraq

Abstract

Ramadi city, western Iraq, is considered an area with risks resulting from the presence of gypsum soil near the surface and the water table on shallow depth which facilitates the solubility of the soil and creates a weak area. So a dipole-dipole array with an n factor of 6 and a -spacing of 2 m was used. Ten 2D resistivity imaging traverses and 3D resistivity imaging station were done. The robust constrained inversion method is used to obtain 2D and 3D models. The results show that the topsoil layer extends to 2m depth with resistivity of 800 to 4000 Ωm. This is caused by high inhomogeneities in the deposits. The weakness zones and Depositional lenses appears after 2m depth and extent to 9m with resistivity value extend from 200 to 800 Ωm. Finally, it is concluded that four main reasons for civil engineering failure in Ramadi city. These reasons may be the inhomogeneity of the underground deposition material. In addition, the existence of weak areas and sedimentation lenses, and the change of water table.