Landslide Soil Failure Parameters Characterization Using Geoelectrical Resistivity Methods in Uruagu, Nnewi, Anambra State, Nigeria
Keywords:
Landslide, Electrical Resistivity, Electrical Sounding, geoelectrical, Wenner-Schlumberger, laboratory index analysisAbstract
Electrical Resistivity Imaging (ERI) and Vertical Electrical Sounding (VES) were deployed over Uruagu landslide area. The main purpose of the geoelectrical resistivity surveys was to characterize the landslide failure parameters in order to identify the soil failure mechanisms.
Ten profiles of 2D Electrical Resistivity Imaging (ERI) measuring 200 m each, and thirty Vertical Electrical Sounding (VES), with three VES along each profile, were executed. Nine of the ten profiles were executed within the landslide site while one profile was executed in a residential street as a control profile. Four soil samples were also taken for physical and geotechnical laboratory index analysis. The PASI resistivity meter was used for the geoelectrical resistivity measurements. The Wenner-Schlumberger array was deployed for the ERI with a minimum electrode spacing of 10 m. The Schlumberger array was deployed for the VES with a maximum current spacing of 130 m. ERI resistivity data analysis involved inversion using RES2DINV software package involving mean model residual and construction of iso-apparent resistivity contour maps. VES resistivity data analysis involved calculated parameters from plotted field data on log-log graph then used as initial models in an iterative forward modeling WinResist software package.
The results of the ERI and VES for the control profile reveal that the subsurface strata are originally composed of silty clay of resistivity values (16.7 – 60.9) Ωm, clayey silty sand having resistivity values (116 – 800) Ωm and sandstone layer with resistivity values (>814 Ωm). The ERI and VES results for the devastated landslide site reveal counteraction material of resistivity values (>814 Ωm), colluvia and regoliths (116 - 300 Ωm) and variably wet weathered sandstones of resistivity values (<60.9 Ωm). The laboratory results revealed the landslide site is majorly composed of silty sandy clay, silty clay, sandy silty clay and sandstones as the pre-landslide existing lithologies. The natural water content ranges from 10.6% to 14.0%. The liquid limit ranges from 44.0% to 46.0%, the plastic limit ranges from 15.0% to 17.0% and the plasticity index from 28.0% to 29.1%.
The geophysical and laboratory results revealed consistency in the lithological units in agreement to the characteristic geology of the study area. The landslide site has high gully slope gradients and collects large volume of floods during intense rainy season. These soils during intense rainfall, imbibe more water, following their high plasticity, slid along the sandstone to Landslideactivate the soil failure.
References
Ayolabi, E. A., Folorunso, A. F. and Jegede, O. E. (2013). An
Application of 2D Electrical Resistivity Tomography in Geotechnical
Investigation of Foundation Defects: A Case Study. Journal of
Geology and Mining Research. Vol. 3 (2); 142-151.
Bisdorf, R.J and Lucius, J.E (1999). Mapping the NormanOklahoma Landfill Contaminant Plume Using Electrical Geophysics.
U.S Geological Survey Water Resources Investigation Report, 6: 99-
Bogoslovsky, V. A. and Ogilvy, A. A. (1977). Geophysical methods
for the investigation of landslides. Geophysics, vol. 42, no. 3, Pp.
–571. Doi:10.1190/1.1440727
Casagrande, A. (1932). “Research of Atterberg Limits of Soils,”
Public Roads, Vol. 13 (8): 121–136.
Chikwelu, E. E. and Chetty, N. (2021). Use of Electrical Resistivity
Tomography in investigating the internalStructure of a landslide and
its groundwater characterization (Nanka Landslide, Anambra State,
Nigeria). Journal of Applied Science and Engineering, Vol. 25, No 4,
Page 763-772 dx.doi.org/10.6180/jase.202208_25(4).0012
Coduto, D.P. (1999). Geotechnical Engineering: Principles and
Practice. Upper Saddle River Prentice Hall Inc
Cruden, D.M and Varnes, D.J. (1996). Landslide types and
processes. Special Report – National Research Council,
Transportation Research Board. Vol 247, pp. 36-75.
Dahlin, L.T., Forsberg, K., Nilsson, A. and Flyhammer, P. (2006).
Resistivity Imaging for Mapping of Groundwater Contamination at
the Municipal Landfill La Chureca, Managua, Nicaragua. Near
Surface 2006, 12th European Meeting of Environmental and
Engineering Geophysics, 4–6 September, Helsinki, Finland
Daily, W. and Ramirez, A.L. (2000). Electrical imaging of
engineered hydraulic barriers. Geophysics, 65(1), pp.83 – 94.
Egbueri, J. C. and Igwe, O. (2021). The impact of
hydrogeomorphological characteristics on gullying processes in
erosion-prone geological units in parts of southeast Nigeria. Geology,
Ecology, and Landscapes 5(3): 227–240. DOI:
1080/24749508.2020.1711637.
Evrett ME. 2013. Near-surface Applied Geophysics.Cambridge:
Cambridge University Press.
Ezemonye, M.N., and Emeribe, C.N. (2012). Rainfall erosivity in
southeastern Nigeria. Ethiopian Journal of Environmental Studies and
Management 5 (2): 112–122.
Igwe, O., Mode, W., Nnebedum, O., Okonkwo, I. and Oha, I. (2013).
The analysis of rainfall-induced slope failures at Iva Valley area of
Enugu state, Nigeria. Environment and Earth Science.
https://doi.org/10.1007/s12665-013-2647
Igwe, O. and Una, C.O. (2019). Landslide impacts and management
in Nanka area, Southeast Nigeria. Geoenvironmental Disaster. 6(5),
pp 1-12.
Kearey, P., Brooks, M. and Hill, I. (2002). An Introduction to
Geophysical Exploration.3rd edition- Blackwell Science Ltd, Oxford,
pp 262.
Loke, M.H. (2001). Electrical Imaging Survey for environmental and
engineering studies: A practical guide for 2D and 3D surveys.
www.geoelectrical.com p.62
Merritt, A.J., Chambers, J.E., Murphy, W. et al.(2013). 3D ground
model development for an active landslide in Lias mudrocks using
geophysical, remote sensing and geotechnical methods, Landslides,
vol 11, no. 4, pp. 537-550. DOI 10.1007/s10346-013-0409-1
McCann, D.M, Forster A (1990) Reconnaissance geophysical
methods in landslide
investigations. Eng Geol 29:59–78
Monanu, S., and Inyang, F. (1975). Climatic regimes. In Nigeria in
Maps (ed. by, ed. G.E.K. Ofomata, 27–29. Benin: Ethiope Publ.
House.
Nfor, B N; Olobaniyi, S B; Ogala, J E (2007). Extent and distribution
of groundwater resources in parts of Anambra State, Southeastern,
Nigeria. Journal of Appl. Sci. Environ. Manage. vol. 11 (2) 215 - 221
Nigeria Meteorological Agency (NIMET) (2007). Daily weather
forecast on the Nigerian Television Authority. Nigerian Metrological
Agency, Oshodi, Lagos
Nwajide, C.S. (1980). Eocene tidal sedimentation in the Anambra
Basin, southern Nigeria. Sedimentary Geology 25: 189–207.
Onyekwelu, C. C. Onwubuariri, C. N. Mgbeojedo, T. I.
AlNaimi, L. S. Ijeh, B. I. Agoha, C. C.(2021) Geoelectrical
investigation of the groundwater potential of Ogidi and environs,
Anambra State, Southeastern Nigeria. Journal of Petroleum
Exploration and Production Technology. doi.org/10.1007/s13202-
-01119-z
Pazzi, V.; Morelli, S. and Fanti, R (2019). A review of the
advantages and limitations of geophysical investigations in landslide
studies. International Journal of Geophysics. v. 2019, pp 27
Perrone, A., Lapenna, V. and Piscitelli, S.(2014).Electrical
resistivity tomography technique for landslide investigation: a
review. Earth-Science Reviews, vol. 135, pp. 65–82.
Rezaei, S.; Shooshpasha, I.; Rezaei, H. (2019). Reconstruction of
landslide model from ERT, geotechnical, and field data, Nargeschal
landslide, Iran. Bulletin of Engineering Geology and the Environment
, v. 78, n.5, p. 3223-3237,.
Sechman, H., Mościcki, W.J. and Dzieniewicz, M. (2013). Pollution
of near-surface zone in the vicinity of gas wells. Geoderma, 197–198,
pp. 193 – 204
Uwaezuoke, C.C., Ishola, K.S. & Ayolabi, E. A. (2021) Electrical
resistivity imaging and multichannel analysis of surface waves for
mapping the subsurface of a Wetland Area of Lagos, Nigeria,
NRIAG Journal of Astronomy and Geophysics, 10:1, 300-319,
DOI:10.1080/20909977.2021.1927427
Whiteman, A (1982) Nigeria: Its petroleum geology, resources and
potentials, vol 1. Graham &Trotman, Londonpressures in the
Anambra basin, southern Nigeria. Hydrol Sci J 42(2):141–154
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2023 ESI Preprints
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
