EXPLORING THE LINKAGES BETWEEN GEOPHYSICAL AND GEOTECHNICAL PROSPECTION TO DETECT FOUNDATION FAILURE OF BUILDINGS IN A WETLAND AREA OF LAGOS, SOUTHWESTERN NIGERIA
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Date
2018
Authors
Adeoti, L
Opene-Odili, P.N
Oyedele, K.F
Oyeniran, T.A
Ishola, K.S
Ayuk, M.A
Journal Title
Journal ISSN
Volume Title
Publisher
Nigerian Research Journal of Engineering and Environmental Sciences
Abstract
The geophysical and geotechnical methods were used to characterize the sub
surface geologic units with a view to establishing the causes of foundation
failure at Oyadiran Estate, Yaba, Lagos, Southwestern Nigeria. 2–D Electrical
Resistivity Imaging, Vertical Electrical Sounding (VES) and Multichannel
Analysis of Surface Wave (MASW) were acquired within the study area. Also, a
Standard Penetration Testing (SPT) boring was acquired to constrain the
geophysical methods. The results of 2–D resistivity and 1-D geoelectric sections
delineated four to five geologic units. These correspond to topsoil, clay/peat,
sandy clay, clayey sand and sand based on resistivity contrast ranging from
0.25 – 226 Ωm. The 2–D resistivity sections emphasized the lateral and vertical
extents of the subsurface geological information. The MASW results revealed
similar geologic units based on shear wave velocity discrimination except in a
few cases which might be due to subsurface dip of the earth materials. An
analysis of a typical geotechnical borehole has assisted to classify sand into
loose, medium dense and dense based on SPT N-values and clay into very soft
arising from cohesion (cu) value. This study has established that the clay
materials with resistivity in the interval of 0.25 – 27 Ωm, Vs values 60 – 80 m/s2
and Cu of 12 -15 kN/ m2could be responsible for the foundation failure. Hence,
the integration of 2–D Electrical Resistivity Imaging, VES and MASW
complemented with a SPT boring has assisted to reduce this uncertainty by
identifying the anomalous zones for detailed and cost effective geotechnical
investigation.
Description
Keywords
Vertical electrical sounding , Shear wave velocity , Standard penetration testing , Anomalous zones , Foundation failure
Citation
Adeoti, L., Opene-Odili, P.N., Oyedele, K.F., Oyeniran, T.A., Ishola, K.S. and Ayuk, M.A.(2018). EXPLORING THE LINKAGES BETWEEN GEOPHYSICAL AND GEOTECHNICAL PROSPECTION TO DETECT FOUNDATION FAILURE OF BUILDINGS IN A WETLAND AREA OF LAGOS, SOUTHWESTERN NIGERIA. Nigerian Research Journal of Engineering and Environmental Sciences, 3(1), 416-427.