[01] Joseph Olakunle Coker, Department of Physical Science, Lagos State Polytechnic, Ikorodu, Nigeria.

Resistivity measurement using 1-D and 2-D resistivity probing techniques and Geotechnical method using Cone Penetrometer Test (CPT) were integrated to delineate the subsurface geology at the School of Management area, Lagos State Polytechnic, Ikorodu. The resistivity measurements were made with Allied Ohmega Resistivity meter. The 1-D vertical electrical resistivity sounding data were obtained using the Schlumberger electrode array while the 2-D resistivity data were obtained using the Wenner array. Two 2.5 tonnes Cone Penetration Test (CPT) and one borehore log was used for control. The acquired VES data were processed and interpreted using partial curve matching technique and 1D computer assisted forward modeling using WinResist software. DiproWin software version 4.0 was to process the 2D data. Based on the results of the investigations, the main lithological unit consists of sandy clay and sand materials It is concluded that the northern part of the study area consist of sandy clay, a mechanically unstable soil formations which is capable of being inimical to building structures and the southern part consist of the sand layer which is viewed as the only competent geo-material for the foundation of any engineering structures within the study area.

Cone Penetration Test, Schlumberger Array, Subsurface Geology, Vertical Electrical Sounding, Wenner Profiling

[01] Ayolabi, E.A., Folorunso, A.F. and Jegede, O.E. 2012. The Application of 2D Electrical Resistivity Tomography in Geotechnical Investigations of Foundation Defects, Ogudu Estate as a Case Study, Journal of Geology and Mining Research, 3(12): 142 - 151. [02] Coerts, A.O. 1996. Analysis of static cone penetration test data for subsurface modelling. A methodology – PhD Thesis, Nethernals Geographical Studies 210, 263pp [03] Coker, J.O. 2015. Geophysical and Geotechnical Assessment of Foundation Failure: A Case Study of Library Complex Area, Lagos State Polytechnic, Ikorodu, Lagos, Nigeria. Research Journal in Engineering and Applied Sciences. Vol.3, No 7 [04] Coker, J.O., Makinde, V., Adesodun, J.K and Mustapha, A.O. 2013. Integration of Geophysical and Geotechnical Investigation for a Proposed New Lecture Theatre at Federal University of Agriculture, Abeokuta, South Western Nigeria. International Journal of Emerging Trends in Engineering and Development Issue 3, Vol.5: 338-348 [05] Enu, E. I. 1985. Textural Characteristic of the Nigerian Tar Sands, Sedimentary Geology, 44: 65-81. [06] Fakere, A. A., Fadairo, G. and Fakere, R.A. 2012. Assessment of Building Collapse in Nigeria: A Case of Naval Building, Abuja, Nigeria, International Journal of Engineering and Technology (IJET), 2(4): 584-592. [07] Fatoba, J.O. and Olorunfemi, M.O. 2004. Subsurface sequence delineation and saline water Mapping of Lagos State, Southwestern Nigeria. Global Journal of Geological sciences 111 – 123pp [08] Griffiths, D.H. and Barker, R.D. 1993. Two dimensional resistivity imaging and modelling in areas of complex geology. J Appl Geophys 29:211–226 [09] Ibrahim, R. B. 2013. Monumental Effects of Building Collapse in Nigerian cities: The case of Lagos Island, Nigeria, Basic Research Journal of Engineering Innovation, 1(2): 26-31. [10] Jones, H.A. and Hockey, R.D. 1964. The Geology of Part of South-Western Nigeria, Geological Survey Nigeria Bulletin, 31: 56 - 86. [11] Lunne, T; Robertson, P.K and Powell, J.J.M. 1997. Cone Penetration Testing in Geotechnical Practise, Blackie Academic and Professional, London, 312p [12] Nton, M.E. 2001. Sedimentological and Geochemical Studies of Rock Units in the Eastern Dahomey Basin, South Western Nigeria, Unpublished PhD thesis, University of Ibadan, 315. [13] Omatsola, M.E. and Adegoke, O.S. 1981. Tectonic Evolution and Cretaceous Stratigraphy of the Dahomey Basin, Journal of Mining and Geology, 8: 30-137. [14] Oyedele, K.F. and Olorode, D.O. 2010. On Site Investigation of Subsurface Conditions using Electrical Resistivity Method and Cone Penetration Test at ‘Medina Brook Estate, Gbagada, Lagos, Nigeria, World Applied Science Journal, 11 (9): 1097-1104. [15] Oyedele, K.F and Bankole, O.O. 2009. Subsurface Stratigraphic Mapping using Geophysics and its impact in urbanization in Arepo area, Ogun State, Nigeria. New York Science Journal (5) 2, pp31 – 45. [16] Sirles, P. 2006. Advancement in 3D Subsurface Modelling using Seismic Refraction Data- A new perspective in Proceedings for GEOPHYSICS 2006, 3rd International Conference on Applied Geophysics, St. Louis MO.