Geotechnical Characterization of some Clayey Soils for Use as Landfill Liner

摘要

Waste management is one of the major challenges faced by municipalityofficials, public health engineers and environmentalists in their quest to protect and preserveour environment. Construction and operation of an engineered sanitary landfill ensures properwaste management with the protection of human and ecosystem health. This paper presentsthe results of geotechnical investigation carried out on clayey soils from three selected potteryareas in Oke Ogun, Oyo State; to assess their suitability for use as landfill liner. Samples werecollected at three locations namely: Ajetunmobi village, sample A; Adegbite area, sample B;and Arigangan area, sample C. Basic index characterization tests conducted on the samplesrevealed percentage fines for samples A,B and C were 32.7%, 28.3% and 37.0% respectively.Specific gravity ranged between and 2 · 71 and 2 · 74. Sample A had Cation Exchange Capacity(CEC) value of 10.58 milli-equivalents/100g (Meq./100g), sample B had CEC value of 11.76(Meq./100g) and sample C had CEC value of 12.18 (Meq./100g) Geotechnical testsconducted on samples resulted in hydraulic conductivity (k) of 1.86 × 10-10m/sec forsample A ; 4.12 × 10-8m/sec for sample B and, 2.60 × 10-10m/sec for sample C. Theresults obtained from the study show that sample A is the best material for a landfill linerbased on the hydraulic conductivity criterion, however all the other samples are also usefuland can be improved by addition of little percentage of bentonite. The compaction andcompressibility characteristics needed in the specifications for the construction and operationof an engineered landfill using these clayey soils are presented.