Effects of leachate on geotechnical properties of lateritic soil

Abstract

The presence of leachate poses a threat to the environment. Soil, water and sometimes air quality are significantly contaminated. This study investigated the effects of leachate contamination on the index properties, compaction and strength characteristics of lateritic soil obtained from Nawfia, Anambra state. Leachate characterization was conducted in the laboratory and its quality documented. Specific gravity, sieve analysis, consistency limits, compaction using British Standard light method (BSL) and unconfined compressive strength (UCS) tests were conducted on the soil samples. From the results, UCS values decreased with increase in leachate content from 229.403 kN/m3 at 0% leachate to 169.941 kN/m3 at 20% leachate. A steady decrease was also observed for the cohesive strength of the samples upon contamination with leachate from 114.701 kN/m3 to 84.97 kN/m3. Liquid limit values decreased from 48.0% to 40.10% at increasing leachate contents from 0% to 20%. Plastic limit also decreased from control value of 32.05% to 21.70% at 20% leachate contamination. BSL compaction tests revealed that increase in leachate content resulted in decrease of maximum dry unit weight (MDUW) and optimum moisture content (OMC) values. These results indicate that the presence of leachate fluid in the soil negatively impacts the strength and geotechnical properties of sandy-clay soil.