Geotechnical Considerations For Road Development In The Meander Belt Of The Niger Delta Region, Nigeria

Increasing number of roads within the swamp area of the Meander belt are needed to access petroleum infrastructure as well as facilitate development within the Niger Delta region of Nigeria. The major challenge of such roads is the prevalence of soft silty/sandy clay layers near the surface and the presence of artesian pressures. Artesian pressures pose some danger to construction and limit the extent of excavation for replacement of weak and unsuitable sub-grade. The soft and weak clay layers on the other hand exhibit low bearing capacity and significant consolidation settlement particularly in places where the clay layers are thick. Consequently it is recommended that excavations must be carried out with caution, bearing in mind the possibility of significant hydrostatic uplift pressures. A chart which enables the rapid determination of depth of excavation under artesian condition has been developed. In situations where Hw/HT &#8805 2, no excavation can be tolerated. Instead, fills would be required. Such fills will serve as surcharge for ground improvement and also elevate ground level above maximum expected flood height. Keywords: Geotechnical, Road, Meander belt, Niger DeltaGlobal Journal of Geological Sciences Vol. 6 (1) 2008: pp. 47-5