Main Article Content
Characterization of terrain and biotite gneiss-derived lateritic soils of Ilorin, Nigeria, for use in landfill barriers
Abstract
barriers and final cover materials. The results of twenty-eight (28) vertical electrical soundings (VES) and five (5) handdug wells over the site revealed that the average thickness of the overburden is 17m; thickness of the lateritic layer is 7.8m on the average while the groundwater table is encountered at depth of 5.3m. The geotechnical assessment of the soil samples revealed that the specific gravity values range from 2.50 - 2.73; the percentage of fines range from 20% - 67%; liquid limits range from 21.64%-46.53% and the plasticity index values range from 13.47% - 25.95%. The maximum dry density values of the soil obtained using the standard Proctor energy of compaction range from 1.72t/m3 -1.97t/m3; while those obtained using modified Proctor energy range from 1.78t/m3 –
2.07t/m3. The highest coefficient of permeability values (6.03 x 10-9m/s) for all soil samples, which is close to the recommendation of 1x10-9m/s by several previous researchers, who obtained their results by using the lower
compaction energy. All the characteristics compared favourably well with those suggested by regulatory agencies and several investigators. Consequently, this study confirms the suitability of the soils and for the construction of landfill facility.