Application of 2D electrical resistivity imaging and cone penetration test (CPT) to assess the harzadous effect of near surface water on foundations in Lagos Nigeria

2017 International Conference on Space Science and Communication

物理学;无线电电子学

Adewoyin, O.O.^1 ; Joshua, E.O.^2 ; Akinyemi, M.L.^1 ; Omeje, M.^1 ; Joel, E.S.^1

Department of Physics, College of Science and Technology, Covenant University, Ota, Ogun State, Nigeria^1

Department of Physics, Faculty of Science, University of Ibadan, Ibadan

Oyo State, Nigeria^2

关键词: Cone penetration tests;    Electrical resistivity imaging;    Geologic formations;    Geological formation;    Hazardous effects;    Resistivity data;    Resistivity surveys;    Two Dimensional (2 D);   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/852/1/012033/pdf
DOI  :  10.1088/1742-6596/852/1/012033

来源: IOP

【 摘 要 】

Adequate information on the condition of the subsurface is very important for site evaluation for engineering purposes. In this study two dimensional (2D) geoelectrical resistivity survey and cone penetration tests were conducted to study the hazardous effect of excess near surface water on the foundation of building in a reclaimed land located at Victoria Island area of Lagos State. The results of the inverted 2D geoelectrical resistivity data revealed three distinct geoelectrical layers characterized by low to moderate electrical resistivity of 2.23 and 129Ωm and 9.46 to 636Ωm respectively. The topsoil is characterized by wet sandy soil, which is underlain by sandy clay and banded at the below by a geologic formation of low resistivity which is suspected to be clay. The clay material may be responsible for the excess water retention observed in the area. The CPT method on the other hand revealed a geological formation of low resistance to penetration between 2-3 kg/cm2from the topsoil to a depth of 7 m, which may be the effect of excess water in the near surface. This study revealed that the foundation of building may not be founded directly on the soil in any reclaimed land as this may result in collapse as a result of upward migration of water to the near surface.