Experimental Analysis of Kerosene’s Contamination Effect on Unit Skin Friction of Pile in Clayey Soil

This study presents an experimental investigation into the effects of subsurface kerosene contamination on the behavior of model piles in clay. Three instrument piles were placed in a compacted clay bed and tested in three saturations in a two-week period: natural moisture content, water-saturated, and kerosene-flooded. The tests performed on the piles were axial compression and pullout tests, supported by unconfined compression and consolidation tests for the clay. The saturating fluid controls the pile capacity, with the water-saturated condition producing the lowest ultimate capacity and the natural condition the highest. Moreover, it was shown that kerosene contamination significantly modified the mechanical characteristics of the clay, thus leading to an order of magnitude increase in the pre-consolidation pressure and a decrease in the compression index by 50% compared to the water-saturated cases. Under pullout loading, the unit skin friction varied linearly with depth, and failure consistently occurred at the pile–soil interface. This demonstrates the applicability of geotechnical design that considers hydrocarbon contamination to significantly decrease pile capacity and substantially change the consolidation characteristics of clayey soils.