Detection of subsurface cracking depth using electrical resistivity tomography: A case study in Masjed-Soleiman, Iran

Abstract Soil cracks affect the engineered earth structures, being known to contribute to failures in road surfacing. Electrical resistivity imaging technique is a generally appealing method to investigate such phenomena. Cracks deviate the resistivity distribution of the soil, since resistivity of the air-filled cracks is significantly higher than the intact soil. In this study, the non-invasive 2D electrical resistivity imaging survey was conducted along two parallel lines using a Wenner-Schlumberger configuration to investigate vertical and horizontal extension of the existing cracks in the structure of a road covered by asphaltic sandstone near Masjed-Soleiman city. From the inverted results, 17 different cracks were detected, which their depths ranged from 0.5 to 5.5 m. However, there is not any considerable crack progressing toward the axis of the road. Borehole drilling confirmed the results of electrical resistivity sections to detect the cracks. The results show that the 2D electrical resistivity imaging survey using the Wenner-Schlumberger array in combination with an appropriate 2D inversion method can be highly useful to delineate vertical extension of the existing cracks in road structures.