Effects of Fractures on Buildings and Road Construction: A Case Study of Area BZ, Ahmadu Bello University, Zaria, Nigeria

Abstract

Structural collapse due to the absence of geophysical information has become a major concern in the construction and building industries today. In this research, we reported the effect of fracture on some selected buildings in Area BZ, Ahmadu Bello University, Zaria. Reflex W software was used to analyze the vertical and horizontal profiles of the subsurface features in two-dimensional (2D) tomography of seismically related regions. The data were collected using MK6 Terraloc seismograph. Seismic refraction method was used to obtain relevant information about the subsurface strata. The velocities of different layers were obtained from the distance-time graph to generate the tomography of the four profiles of 115 m distance each. Results revealed that there are fractures beneath the surface, starting from the depth of 10 m into the basement region as evident in the four (4) profiles with variations in the seismic velocities of 1652 to 2086 m/s and 2521 to 2955 m/s for given strata. The 2D tomography of the study area also revealed that the eastern parts of profiles 1-3 may not be safe for the erection of buildings and other structures without excavation, while profile 4 revealed high levels of structural deformation and it is recommended as a high-risk region that will not support engineering structure. We, however, recommend that further geophysical surveys should be carried out in the area, using Electrical Resistivity Tomography (ERT).