Appraisal of the causes of pavement failure along the Ilesa - Akure Highway, southwestern Nigeria using emotely sensed and geotechnical data

Abstract

Remotely sensed and geotechnical data have been used to establish some of the causes of perpetual pavement failure along the Ilesa Akure highway in the southwestern part of Nigeria. Four failed segments and two control stable segments were selected for the geotechnical study. The remote sensing investigation involved the processing and interpretation of Landsat-7 ETM+ images covering the study area and it's environ for lineaments. The geotechnical investigation involved grain size analyses, Atterberge Limits, Compaction Test and California Bearing Ratio (CBR) determination. Lineaments were identified across virtually all the failed localities with a predominantly N-S structural trend. The geotechnical properties of the soils beneath the stable and failed segments of the highway show significant overlap which suggests that the cause of road pavement failure along the highway may be due to factors other than or complimentary to the geotechnical factors. The pavement failure may have resulted from suspected near-surface linear (geological) features such as faults/fractures and lithologcal contacts beneath the highway pavement. Clayey substratum and ponded embankment toe could also have contributed to the pavement failure.

Keywords: Remote Sensing, Geotechnical Investigation, Road Pavement Failure, Basement Complex
Environment