Site Characterization of an Abandoned Dumpsite for Engineering Purposes Using Integrated Techniques

Abstract

Subsurface information of an abandoned dumpsite at Saje Abeokuta, South-western Nigeria was investigated using geophysical and geotechnical methods (ES). The combination of four traverses measured at 5 m constant sampling interval using to determine its suitability to host engineering structure (ES). Dipole-dipole configuration and Eight Vertical Electric Sounding (VES) were carried out. Laboratory tests were performed on eight samples obtained from 1 m depth to determine particle size distribution, Atterberg limit, compaction limit, California bearing ratio (CBR), specific gravity and moisture content. The resulting sounding curve include the AH, KH, HKH and H and maximum of five geo-electric sub-surface layers were revealed. The geoelectric result showed VES 3 and VES 5 as having layers composed of fractured basement and clayey sand offer weak support for ES. Traverse 1 and 4 from 2D ERT have reasonable linearity in the topsoil which is mechanically stable in supporting shallow foundation of ES. All soil samples were mechanically stable as revealed by the CBR test analysis, except L6 which has a low load-bearing ratio. Areas within Traverse 3 are unsuitable for ES without excavation and reinforcement. The study area is suitable to host ES except around VES 3 and VES 5 that need reinforcement.