Post Foundation Geophysical Investigation of the Former Faculty of Arts Building, Ekiti State University, Ado-Ekiti, Nigeria

Main Article Content

Henry Y. Madukwe
Ifeoluwa J. Talabi

Abstract

Aims: This study entails the geophysical approach for the post foundation investigation using magnetic prospecting and impact method of electromagnetism.

Study Design: Traverses and GPS stations of the area were taken.

Place and Duration of Study: The former Faculty of Arts building at Ekiti State University. Ekiti State University is located along Ado-Iworoko road in Ado-Ekiti, Ekiti State which is located in southwestern Nigeria. The work was on 3rd of October 2019.

Methodology: The instrument used in the ground magnetic data acquisition was the proton precession magnetometer. The study area was divided into four traverses that are 100 m long perpendicular to the strike line i.e. the traverse runs from east to west of the study area. A spacing of 5 m serving as stations were maintained on each traverse making a total of eighty stations was accumulated for the four traverses. The impact method of electromagnetics was carried out immediately after the ground magnetic method, the only alteration was the establishment of sub-stations immediately after each station at 2.5 m away from the main station at each traverse. The creation of sub-stations is to comb the study area and obtain a concise data so as to delineate each of the subsurface structures.

Results: The generated geomagnetic contour map of the study area indicates that the central region with high magnetic value implies competent formation, while the extreme North West has low magnetic values suggesting unstable formation. Electromagnetic Profiles of Traverse EFA-1 is a very conductive zone from top to bottom and can be classified as a very weak zone. It cannot bear the load of the structure that was placed on it and thus not a safe site. The weakness of the zone may lead to differential settlement. Traverse EFA-2 defines a fairly competent zone of weathered or a fractured bedrock typically a weathered zone of intermediate value; it can still bear the load of a structure. Traverse EFA-3 is a zone of weathered/fractured bedrock. It has an intermediate potential and evidence of a linear fracture. In traverse EFA-4 is not a competent zone of low to intermediate value. The low value zones may be seasonally wet and dry which can affect the stability of the foundation.

Conclusion: Data analysis delineated suspected fractured, shear or faulted zones and also revealed that the collapsed Faculty of Arts building was sited within the incompetent clayey weathered layer; these weak zones were detrimental to the integrity and stability of the structure.

Keywords:
Building failure, differential settlement, fracture, post foundation, traverse.

Article Details

How to Cite
Madukwe, H. Y., & Talabi, I. J. (2021). Post Foundation Geophysical Investigation of the Former Faculty of Arts Building, Ekiti State University, Ado-Ekiti, Nigeria. Asian Journal of Geological Research, 4(1), 19-32. Retrieved from https://journalajoger.com/index.php/AJOGER/article/view/30121
Section
Original Research Article

References

Olubi AR, Adewolu TO. Impacts of building collapse on sustainable development in Nigeria. Journal of Culture, Society and Development. 2018;44:35-50.

Douglas J, Ransom WH. Understanding building failures, 3rd edn. New York: Routledge. 2007;326 .

Oni AO. Analysis of incidences of collapsed buildings in Lagos Metropolis, Nigeria. International Journal of Strategic Property Management. 2010;14:332–346.

Oyedele KF, Okoh C. Subsoil investigation using integrated methods at Lagos. Nigerian J. Geol. Mining Res. 2011;3:169-179.

Aroyehun MT, Akintorinwa OJ. Application of geophysics in post foundation study: A case study of the faculty of social science building, Phase I, Federal University, Oye-Ekiti, Southwestern, Nigeria. J. Geol. & Geophys. 2018;7(1):2-8.

Akintorinwa OJ, Abiola O. Emerging trends in engineering and applied sciences. J. Emerging Trends Eng App. Sci. 2011;21: 858-863.

Tomlingson MJ, Boorman R. Foundation design and construction. longman scientific and technical: Singapore. 1999;1-125.

Reynolds JM. An introduction to applied and environmental geophysics. John Wiley and Sons, Ltd.: West Sussex, England. 1997;796.

Morrow CA, Moore DE, Lockner DA. Permeability reduction in granite under hydrothermal conditions. Journal of Geophysics Research and Solid Earth. 2001;106:30551-30560.

Marrita. Presented at short course II on surface exploration for geothermal resources, organized by UNU-GTP and KenGen, at Lake Naivasha, Kenya; 2007.

Henkel H, Guzmam M. Magnetic features of fracture zones. Geoexploration. 1977; 15:173-181.

Hersir GP, Björnsson A. Geophysical exploration for geothermal resources. Principles and applications. UNU-GTP. report 15. 1991;94.

Jiracek GR. Near-surface and topographic distortions in electromagnetic induction. Surveys in Geophysics. 1990;11:163-203.

Richard K, Paul B. Mapping groundwater in regolith and fractured bedrock using ground geophysics: A case study from Malawi, SE Africa. Canadian Society of Exploration Geophysics (CSEG). 2004;24 33.

Sharma SP, Baranwal VC. Delineation of groundwater-bearing fracture zones in a hard rock area integrating Very Low Frequency Electromagnetic and Resistivity data. Journal of Applied Geophysics. 2005; 57:155-166.

Sultan SA, Hatem MM, Santos FAM, Abd Alla M. Geophysical measurements for subsurface mapping and groundwater exploration at the central part of the Sinai Peninsula, Egypt. The Arabian Journal for Science and Engineering. 2009;34(1A): 103-119.

Oyegoke SO, Ayeni OO, Olowe KO, Adebanjo AS, Fayomi OO. Effectiveness of geophysical assessment of boreholes drilled in Basement Complex terrain at Afe Babalola University using electromagnetic (EM) method. Nigerian Journal of Technology. 2020; 39(1):36 – 41.

Rahaman MA. Recent advances in the study of the basement complex of Nigeria. Edited by Nigeria Geological Survey. 1988; 11-43.

Adebayo WO. Weather and Climate. In FS. Ebisemiju (Ed.), Ado-Ekiti Region. A Geographical Analysis and Master Plan. Alpha Prints, Lagos, Nigeria. 1993;11-14.

About Nigerians; 2020.
Available:http://aboutnigerians.com/list-of-36-states-in-nigeria-with-their-capitals-current-governors-and-title-slogan/
Accessed 13 May 2020.

Oyedele AA. Use of remote sensing and GIS techniques for groundwater exploration in the basement complex terrain of Ado‑Ekiti, SW Nigeria. Applied Water Science. 2019;9(51):1-13.

Ademilua LO, Eluwole AB, Bawallah M. Geophysical Investigation for Subsurface Integrity Assessment and Its Implications on Existing and Proposed Building Around the Southwestern Part of Ekiti State University Campus, Ado-Ekiti, Southwestern Nigeria. International Journal of Advancement in Engineering Technology, Management and Applied Science. 2015;2(2):2349-3224.

Ajibade AC, Woakes M, Rahaman MA. Proterozoic crustal development in the Pan-African regime of Nigeria. A. Kroner (Ed.), Proterozoic Lithospheric Evolution, Geophysical Union Geodynamics Series. 1987;17:259-271.

Parasnis DS. Principles of applied geophysics. 4th Edition. London, Chapman and Hall. 1986;33-35.