Geotechnical Evaluation of Some Lateritic Soils from Ore, Southwestern Nigeria as Liners in Landfills

Abstract

Liners are very important part of engineered landfills as they control the migration of leachates and other toxic constituents into underlying aquifers or nearby rivers, thereby contaminating the local water. Hence, materials to be used as liners should be able to stand the test of time and provide reliable leak protection. The suitability of some lateritic soils from Ore in southwestern Nigeria has been investigated for the purpose. Six bulk samples of lateritic soils were collected from the study area and subjected to engineering geological tests which include grain size distribution, Atterberg limit, specific gravity, compaction and permeability.  Results indicate that the soils contain clay (24-37%), silt (18-28%), sand (19-38%) and Gravel (10-16%). Atterberg limits test also indicate that the liquid limit values range from 37-46%, plastic limit from 17.26%-19.20% and plasticity index from 16.58%-21.81%. Specific gravity values range from 2.60-2.70, maximium dry density range from 1730.25-1780 kg/m3, optimum moisture content varies from 17.96-19.20 while the permeability varies from 2.95 ×10-12 m/s to 8.34 ×10-12 m/s.  The soils were adjudged suitable for use as liners as they compare favorably with the recommendations of earlier investigators.