Geohazard characterization of subsurface materials using integrated geophysical methods for post foundation studies: a case study

Abstract

Different geophysical approaches including seismic refraction, electromagnetic resistivity with very low frequency and magnetics prospecting method were used to gain a richer and more complete understanding of subsurface environment in delineating the origin of the cracks on the buildings of the Faculty of Social Sciences and Humanities, Federal University Oye- Ekiti. Three (3) profiles of seismic refraction, Five (5) Very Low Frequency-Electromagnetic traverses, twenty-one (21) Vertical Electrical Soundings and three (3) magnetic profiles were occupied and investigated around the distress building. Three major layers were delineated in the study region comprising the topsoil, the weathered/fractured layer and the fresh basement. The VES curve types obtained were A, H, K and Q curves. The buildings were found to be situated within the area of a fairly high concentration of fractures that can aid subsidence in the area and relatively low resistivity zones typical of incompetent clay formation. The geovelocity layers’ characteristics substantiate the electrical resistivity imaging and vertical electrical sounding results as it revealed a 3-layer model namely: topsoil and basement bedrock as the weathered layer is blinded. The topsoil has average velocity 363 m/s which is diagnostic of weak/unconsolidated materials presumably clayey materials and average thickness of 1.7 m. The sub-weathering/ is blinded while the third layer is the bedrock with average velocity of 1183 m/s and characterized with a displaced parallel time segment indicating fault within the bedrock. From the result, the building failure observe as cracks and foundation subsidence may have been caused by the foundation soils that made up of incompetent materials (clay) which could compress on imposing loads by differential settlement. It is noteworthy that geological features such as fractures/faults delineated within the bedrock is also inimical to the building foundation.

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References

  1. Ackermann HD, Pankratz LW, Dansereau D (1986) Resolution of ambiguities of shallow refraction travel-time curves. Geophysics 51:223–235

    Article  Google Scholar 

  2. Adeleke BO, Leong GC (1978) Certificate physical and human geography, west, African edn. Oxford University Press, Nigeria

    Google Scholar 

  3. Adesida A, Omosuyi GO (2005) Geoelectric Investigation of Bedrock Structures in the Mini- campus of the Federal University of Technology, Akure, Southwestren Nigeria, and the geotechnical significance. Niger J Pure Appl Phys 4:32–40

    Google Scholar 

  4. Barry KM (1967) Delay-time and its application to refraction profile interpretation. In: Musgrave AW (ed) seismic refraction prospecting. Society of Exploration Geophysicists, Tulsa

    Google Scholar 

  5. Federal Ministry of Works and Housing (1972) Highway manual part 1 road design. Federal Ministry of Works and Housing, Lagos

    Google Scholar 

  6. Olorunfemi MO, Idoringie AI, Coker AT, Babadiya GE (2004) The application of the electrical resistivity method in foundation failure investigation. J Appl Geosci 2(1):139–151

    Google Scholar 

  7. Oyedele KF (2009) Engineering geophysical approach to progressive or sudden collapse of engineering structures in Lagos Nigeria. J Am Sci 5(5):91–100

    Google Scholar 

  8. Rahaman MA (1989) Review of the basement geology of southwestern Nigeria. In: Kogbe CA (ed) Geology of Nigeria. Rock View (Nig.) Limited, Jos

    Google Scholar 

  9. Sharma SK (1967) Response characteristics and stability of earth dams during strong earthquakes. PhD Thesis, Imperial College, University of London

  10. Vander Velper BPA (1988) Resist Version 1.0, M.Sc. esearch Project, ITC. Delft, Netherlands

  11. Venkatranmaiah C (2006) Geotechnical engineering. New Age International Limited Publisher, Chennai, pp 541–603

    Google Scholar 

  12. Walker C, Leung TM, Win MA, Whiteley RJ (1991) Engineering seismic refraction: an improved field practice and a new interpretation method. Explor Geophys 22:423–426

    Article  Google Scholar 

  13. Whiteley, R.J., Eccleston, P.J., (2006) Comparison of shallow seismic refraction interpretation methods for regolith mapping: 18th ASEG Geophysical Conference and Exhibition, paper. p23

Download references

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Correspondence to Akindeji O. Fajana.

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Fajana, A.O. Geohazard characterization of subsurface materials using integrated geophysical methods for post foundation studies: a case study. Model. Earth Syst. Environ. 7, 403–415 (2021). https://doi.org/10.1007/s40808-020-00861-3

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Keywords

  • Electrical resistivity
  • Foundation
  • subsidence
  • Building and fractures