Geotechnical appraisal of failed sections of some highway pavements in parts of Northcentral Nigeria
Abstract
Purpose
The purpose of this study was to investigate the likely causes of failure of some sections of road pavements in Ajaokuta, Northcentral Nigeria. This was achieved through a geotechnical assessment of subgrade soils in affected areas.
Design/methodology/approach
The methods entailed field and laboratory methods and statistical analysis. Subgrade soil samples were retrieved from a depth of 1,000 mm beneath the failed portions using a hang auger. The soils were analyzed for natural moisture content (NMC), Atterberg limit (liquid limit, plastic limit and linear shrinkage), grain size distribution, compaction and California bearing ratio (CBR), respectively.
Findings
The results of the geotechnical tests ranged from NMC (12.5%–19.4%), sand (84%–98%), fines (2%–16%), LL (16.0%–32.2%), PL (17%–27.5%), LS (2.7%–6.4%), PI (2.5%–18.4%), maximum dry density (1756 kg/m2–1961 kg/m2), optimum moisture content (13.2%–20.2%), unsoaked CBR (15.5%–30.5%) and soaked CBR (8%–22%), respectively. Pearson’s correlation coefficient performed on the variables showed that some parameters exhibited a strong positive correlation with r2 > 0.5.
Research limitations/implications
Funding was the main limitation.
Originality/value
Comparing the results with Nigerian standards for road construction, and the AASHTO classification scheme, the subgrade soils are competent and possess excellent to good properties. The soils also exhibited very low plasticity, a high percentage of sand, high CBR and low NMC, which implies that it has the strength required for road pavement subgrades. The likely causes of the failures are, therefore, due to the use of poor construction materials, technical incompetence and poor compaction of sub-base materials, respectively.
Keywords
Acknowledgements
The authors appreciate the assistance of the laboratory staff of the Department of Geology Federal University Lokoja for allowing the authors to access some of the field equipment for this research. Staff of the Engineering Geology Laboratory of Federal University Akure, Nigeria are also appreciated for carrying out the laboratory tests.
Funding: The authors did not receive any financial support for this research.
Author’s contributions: The design and conceptualization were done by Ernest Orji Akudo. All authors were part of the fieldwork. Emmanuel K. Adekunle and Muawiya Baba drew some of the diagrams, while Ernest Orji Akudo compiled the report, and Kizito O. Musa, Godwin Okumagbe Aigbadon, Nanfa Andrew Changde and Muawiya Baba all reviewed the compiled manuscript.
Declarations: The authors have no competing or financial interest to declare.
Citation
Akudo, E.O., Aigbadon, G.O., Musa, K.O., Baba Aminu, M., Changde, N.A. and Adekunle, E.K. (2024), "Geotechnical appraisal of failed sections of some highway pavements in parts of Northcentral Nigeria", World Journal of Engineering, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/WJE-08-2023-0288
Publisher
:Emerald Publishing Limited
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