The need for ENVIRONMENTAL GEOPHYSICS: the case of abandoned complex behind UBA and FIDELITY banks near Greenhouse at Nsukka campus of University of Nigeria

Abstract

Subsurface geologic structure around an abandoned building at the University of Nigeria, Nsukka campus was investigated to ascertain the cause or reason for abandonment. 2-D resistivity method was employed in the study. Three electrical resistivity tomography (ERT) profiles and one vertical electrical sounding (VES) profile were conducted around the building using SSR-MP-ATS resistivity meter. Winresist software and RES2DINV software were used to process the VES and ERT data respectively. The result of the analysis of the VES data showed a six layered earth model with the resistivity and depth respectively for each layer. The results of the ERT revealed that the area is covered with a conductive top-layer to a depth of about 15 m coupled with fault zone that passed through the building site. These results showed that the foundation of the building was laid without priori or adequate geologic information about the site before commencement of the building. Geologically, the areas with a conductive layer or fault zone have earth materials with low or poor engineering strength that could lead to collapse of engineering structure either by sinking or by fall and which is the case with this site we have studied.