Mineralogical and Geotechnical Properties of Subgrade Soils Along Failed Portions of Abavo-Urhonigbe Road, Western Niger Delta, Nigeria

This paper present the investigation of possible causes incessant road failure associated with subgrade soils Niger delta using mineralogical and geotechnical properties assessment. Geotechnical revealed clayey sand form bulk composed generally fine to medium grains low intermediate plasticity. Based on AASHTO soil classifies as A-2 A-6 granular being dominant. The average values obtained for California Bearing Ratio (CBR), maximum dry density (MDD), optimum-moisture-content (OMC) shear strength are 19%, 1726 kg/m3, 15.70% 286 KPA respectively. angle friction ranged from 180 250 indicates high presence sand. X-ray diffraction analyses reveal absence expandable clay mineral. Collapse potential 1.3 10.8% indicating slight severe collapse. High amount settlement field observation intense collapsible, particularly when inundated under poor drainage conditions. Thus, failures observed in study a result inherent design relative Region peculiar geomorphological climatic