A Geotechnical Investigation on the Failure of Road Pavements in Abakaliki, Southeastern

Abstract

assess deformation and structural design of failed pavements; in order to suggest improvement approach on the engineering properties of the pavement materials. California Bearing Ratio (CBR) and in-situ density were performed on the subbase materials while soil samples were subjected to particle size analysis, Atterberg limit, density and CBR laboratory tests. Field study revealed level of deformation for categorized sections of the studied road in the area. Results of laboratory tests showed subbase liquid limit (LL), plastic limit (PL) and plasticity index (PI) range as follows: LL 29–45%, PL 18–30%, and PI 11–16 for Presco – Ishieke Junction section with soaked subbase and CBR of 18–36% and subgrade soaked CBR between 17 and 20%. The Spera-In-Deo–Onuebonyi section has LL of 38–50%, PL of 23–35% and PI of 12–16 whereas LL range of 38–41%, PL range of 27–29%, CBR of 29–31% and PI range of 11–12 were recorded for the Spera-In-Deo–Mammy market section. Investigation revealed two different soil types used for subgrade: A–2–7 and A–7–5 both with moderate liquid limit and plasticity index values. The particle size distribution curves for AA, AO and EA indicate that AA and AO soils are well graded (poorly sorted) than EA, therefore have the fairest engineering properties. Failures were concentrated on unstabilized roads; hence sand stabilization is required on the soil types used as subbase material. Poor subbase material associated with water sources is responsible for road failures in Abakaliki

Publication Info:

Author: Babadiya, E.G. and Igwe, E.O

Volume: 57

Issue: March

Published By: NMGS, 2021-03-03