This study investigated soil competence in Cross River University of Technology, Calabar Campus using Electrical Resistivity Tomography (ERT) method. The major equipment employed in the study was the Resistivity Meter Model SSR-MP-ATS by IGIS (India) that can measure earth resistances with an accuracy of 1μΩ with 24V rechargeable batteries and other accessories. The findings of the study revealed that in ERT1, moderately competent soil has resistivity less than 150 Ώm while the resistivity of competent and highly competent soils ranges from 373 Ώm to >750 Ώm. In ERT 2, the resistivity values of moderately competent soil lie between 175 Ώm and 272 Ώm and that of competent and highly competent soil lie between 421 Ώm and > 750 Ώm. In ERT 3, small portion of incompetent soil was observed with resistivity value less than 100Ώm. Other sections of the profile are characterized by competent and highly competent soil with resistivity values ranging from 113 Ώm to > 750 Ώm. In ERT 4, a pocket of incompetent soil was observed with resistivity value less than 100 Ώm. Other portions of the profile are characterized by moderately competent soil and competent soil with resistivity ranging from 148 Ώm to 580 Ώm. The implication of this study is that the soils in the study area are suitable and competent for the erection of any civil engineering structures such as buildings, masts etc. It is therefore recommended that geotechnical methods should be integrated with geophysical methods to get a full picture of the area.
Keywords: Electrial resistivity tomography, soil competence, geophysical methods, geotechnical method, Calabar campus.