Effect of Rate of Crude Oil Contamination on Index Properties and Engineering Properties of Clays and Sands

Abstract

Background: The recent advancements and industrial growth has adversely affected the environment which has direct or indirect impact on geotechnical properties of soil. One of the most perturbed sources of contamination is crude oil contamination, which basically takes place either due to accidental spillage of crude oil or through the industrial waste. This leads to alternation of index properties, chemical properties as well as engineering properties of soil. Methodology: Many researchers have worked on studying the impact of crude oil contamination on various types of soil. Present research work, focuses on not only evaluating the extent of alternation of the index properties (Specific Gravity, Liquid Limit, Plastic Limit, Shrinkage Limit) as well as engineering properties (Free Swelling Index) for Kaolinite Clay and fine grained sand due to crude oil contamination but also the effect of rate of crude oil contamination viz. 3%, 6% and 9% of crude oil contamination on both the soil types by performing geotechnical tests in accordance with IS Code:2720 part 3-1 (1980), part 5,6 (1985), part 40 (1977) respectively on non-contaminated soil samples as well as crude oil contaminated soil samples. For this purpose, the crude oil contaminated samples were prepared in the laboratory at water content equal to the liquid limit; simulating the in-situ conditions. Findings and Conclusion: The results thus obtained find its application in comparing the effect of crude oil on fine grained and coarse grained soil. The coarse grained soil (sand) due to its inherent structure and high permeability allows the penetration of crude oil at higher rate than that of fine grained soil (clay) which have low permeability and thus are less liable to get affected due to crude oil contamination. Increment in rate of crude oil contamination can be stated for the deterioration of geotechnical properties for both the soil types.