Malaysian Journal of Geosciences (MJG)

ABSTRACT

APPLICATION OF SEISMIC REFRACTION METHOD FOR GEOTECHNICAL INVESTIGATION OF FUPRE CAMPUS AND ITS ENVIRONS’ SUBSURFACE STRUCTURES

Journal: Malaysian Journal of Geosciences (MJG)
Author: Olaseni V.B, Esi E.O, Chukwusa F.O, Umana Ondu And Sibebo T

This is an open access article distributed under the Creative Commons Attribution License CC BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

DOI: 10.26480/mjg.02.2025.140.145

The conventional approach to subsurface investigation (drilling and trenching) always result to shallow sub-structural information. This challenge now informed the application of seismic refraction method in 3 locations FUPRE-Campus, Okorikperhe, and Okoukouko for geophysical characterization. Twelve traverses were investigated using a 24-channel seismograph and the subsurface images in all locations revealed the presence of three subsurface layers. It is observed that there is a gradual increase of seismic velocities values with depth, first layer ranged from 113.02 to 235.45 m/s, the second ranged between 215.29 and 422.88 m/s while the third layer ranged 492.10–973.63 m/s, this showed that the subsurface experienced high pressure with depth. The first two layers is suspected to be composed of silty-sand formation due to the lower value of shear modulus that ranged 20.20 to 91.32 MPa while the third layer that has the highest seismic velocity value is classified as a dense sand environment due to its higher shear modulus value of 594.38 MPa. The values of other modulus (bulk and young modulus) also increased progressively from first to third layer across the study area and this further confirmed the stronger resistance to deformation with depth. However, the subsurface images generated also revealed a consistent very low value of poisson’s ratio of 0.35 indicating a low measure of deformation in the study area, while the low-density value of 1800 kg/m³ suggested a sedimentary rock composition. In conclusion, the third layer of the study area is the most suitable foundation zone for massive structural development.