Geophysical Investigation of the Causes of Building Cracks in a Basement Complex Terrain of FUNAAB, Southwest Nigeria

Abstract

Building failure is of great concern in the construction industry all over the world. Several kinds of activities can result in the failure, which oftentimes leads to loss of lives and properties. Among several other causes, instability of the ground is a critical factor that causes building collapse in Nigeria particularly in the urban areas like Lagos and Abeokuta. This important factor however is often neglected in the course of many investigations before construction. Whereas early researches have shown that instability of the foundation of a structure is largely traceable to the characteristic of the soil. Electrical resistivity Method (ERM) is a geophysical method capable of giving useful information about the subsurface. Result of the electrical resistivity tomography from the study area showed that the average depth of the top soil is 0.97 m. Top soil is often characterized by low bearing capacity, which makes it to be unstable when loaded with buildings. Conclusively therefore, the ground in the study area must be dug to a depth of about 1.0 m to be able to completely remove the top soil to have a good building foundation that can withstand the building stress.