Abstract
Geophysical investigation using Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT) and Seismic Refraction at a proposed conference center site along Ajibode-Labani road, Ibadan, southwestern Nigeria has been carried out. The investigation aims at characterizing and delineating the subsurface strata to understand the weathered profile at the site. Understanding the weathered profile is essential in determining the suitability of the site for engineering construction of the future conference center. A total of 25 VES and 10 ERT profiles were acquired in a systematic grid pattern using both Schlumberger andWenner configurations with Allied omega terrameter. TheVES data were processed and analyzed using WinResist and the ERT data were inverted using RES2DINV. The data were combined to form a 3-D data set of the site and RES3DINV was used to produce the depth slices. Seismic refraction data were also acquired with an ABEM seismograph and processed using SeisImager and Fajseis software. Seismic data were used in understanding the velocity distribution and thickness. The results of VES, ERT and seismic refraction show good correlation. Four sub-surface layers were delineated: top layer of reworked sand, clayey sand/ lateritic hard pan, clay/ sandy clay and fracture/ fresh basement. The 3-D model permits a pictorial view of the sub-surface in relation to materials that overlie the basement. The thickness of unconsolidated materials to bedrock varies from 2.7 m to 12.2 m which revealed inhomogeneity in weathering under the shallow sub-surface. It is found that the integrated geophysical tool is well suited to characterize and delineate sub-surface structure (weathered profile) for engineering site characterization.
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References
Adesida, A. and Omosuyi, G.O. (2005) Geoelectric investigation of bedrock structures in the mini-campus of the Federal University of Technology Akure, Southwestern Nigeria and the geotechnical significance. Nigeria Jour. Pure Appld. Physics, v.4, pp.32–40.
Al Fouzan, F. and Dafalla, M.A. (2013) Study of cracks and fissures phenomenon in Central Saudi Arabia by applying geotechnical and geophysical techniques. Arab Jour. Geosci. DOI 10.1007/s12517-013-0884-7.
Alisiobi, A.R. and Ako, B.D. (2012) Groundwater investigation using combined geophysical methods. AAPG annual convention poster presentation.
Egwuonwu, G.N. and Osazuwa, I.B. (2011) Geophysical and geotechnical investigation of the origin of structural instabilities shown on some low rise buildings in Zaria, northwestern Nigeria. Pacific Jour. Sci. Tech., v.12, no.2, pp.534–547.
Fajana, A.O., Oladunjoye, M.A., Olayinka, A.I. (2014) Computation of low velocity layer correction parameters by computer models. Jour. Pure Appld. Sci. Tech., v.25, no.2, pp.46–62.
Gay, D.A., Morgan, F.D., Vichabian, Y., Sogade, J.A., Reppert, P., Wharton, A. E. (2006) Investigations of andesitic volcanic debris terrains. Part 2:Geotechnical. Geophysics, v.71, pp.B9–B15.
Kearey, P., Brooks, M. and Hill, I. (2002) An Introduction to geophysical exploration. Blackwell Science Ltd. Third edition.
Neil, A. and Ahmed, I. (2006) A generalized protocol for selecting appropriate geophysical techniques. Department of Geology and Geophysics, University of Missouri, Rolla, Missouri, 19p.
Nigerian Geological Survey Agency (NGSA) (2004) Topographical Map of Ibadan. Published by the authority of the Federal Republic of Nigeria.
Ofomola, M.O., Adiat, K.A.N., Olayanju, G.M. and Ako, B.D. (2009) Integrated Geophysical Methods for Post Foundation Studies, Obanla Staff Quarters of the Federal University of Technology, Akure, Nigeria. Pacific Jour. Sci. Tech., v.10, no.2, pp.93–111.
Olayinka, A.I. and Olayiwola, M.A. (2001) An integrated used of geoelectrical imaging and hydrogeochemical methods in delineating limits of polluted surface and groundwater at a landfill site in Ibadan area, Southwestern Nigeria. Jour. Min. Geol., v.37, no.1, pp.53–68.
Oyediran, I.A. (2010) Geotechnical Evaluation of a site at Ajibode, Ibadan for Landfill: Unpubld. PhD Thesis, Dept. of Geology, Univ. Ibadan, Ibadan.
Samouëlian, A., Cousin, I., Tabbagh, A., Bruand, A., Richard, G., (2005) Electrical resistivity survey in soil science: a review. Soil & Tillage Res., v.3, pp.173–193.
Susan, E.P. (2004) The role of geophysics in 3-D mapping. Geological Survey of Canada. ON, KIAOE8, Canada, 5p.
Soupios, P.M, Georgakopoulos, P., Papadopoulos, N., Saltas, V., Andreadakis, A., Vallianatos, F., Saoris, A. and Makris, J.P. (2007) Use of engineering geophysics to investigate a site for a building foundation. Jour. Geophys. Engg., v.4, pp.94–103.
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Oladunjoye, M.A., Salami, A.J., Aizebeokhai, A.P. et al. Preliminary geotechnical characterization of a site in southwest Nigeria using integrated electrical and seismic methods. J Geol Soc India 89, 209–215 (2017). https://doi.org/10.1007/s12594-017-0585-z
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DOI: https://doi.org/10.1007/s12594-017-0585-z