Michael Kingsley Afful
Senior Engineer, Innovative Solutions Consultancy (SL) Ltd., Freetown, Sierra Leone
Publications
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Research Article
Geoelectrical Characterization and Volumetric Assessment of Rockfill in Swampy Terrains: A Case Study of the Moyamba Junction to Moyamba Town Highway, Sierra Leone
Author(s): Abdul A. Koroma*, Phodie M. Kamara and Michael Kingsley Afful
This study presents a comprehensive geoelectrical investigation of rockfill quality and volume along the newly constructed highway from Moyamba Junction to Moyamba Town, Sierra Leone. The primary objective was to verify the structural integrity and compute the precise volume of rockfill deposited at 14 critical locations, including swamp crossings, box culvert beddings, and weak soil segments. Utilizing the ASTM G57-06 Wenner Four-Electrode method, Vertical Electrical Soundings (VES) were conducted to delineate the subsurface resistivity profiles. Field resistance data were processed using EarthImager 1D inversion software, yielding layered models with high reliability (predominant RMS errors < 5%). The results reveal a consistent high- resistivity signature for the rockfill, ranging between 1000 Ωm and 2000 Ωm, which is diagnostic of high-strength, unweathered crystall.. Read More»