Influence of Diesel Contamination on Engineering Properties of Soil and Its Mechanism

A series of laboratory experiments were conducted to study the change in the engineering geological properties of diesel-contaminated soil. Soil samples with different contaminant concentrations were manually prepared via mixing and static compaction methods. The influence of diesel contamination on engineering properties of the soil was analyzed from the perspective of granulometric composition, Atterberg limits and indices, mechanical properties and microstructural features, and its mechanism of action was discussed. The results showed that contaminated soil contained more fine particles, and a sample with 8% diesel had the highest clay content. With increasing contamination, the plastic limit decreased slightly; the liquid limit increased initially and reached its peak value at 8% diesel content and thereafter decreased slightly. The sample with 4% diesel content had a higher unconfined compression strength than the uncontaminated sample and other contaminated samples. The microstructure changed from an aggregated fabric into a dispersed fabric after the addition of diesel, decreasing the strength of soil.