Experimental and Numerical Analysis of the Behavior of Collapsible Loess under Infiltration of Nonaqueous Phase Liquids

Leakages from fuel tanks and fuel transport pipelines are common occurrences that affect the environment and the geotechnical properties of geomaterials, which is of significant relevance in the case of unstable soils. In this work, experimental and numerical analyses were conducted to study the effect of kerosene on the mechanical behavior of collapsible soils. The compressibility tests on undisturbed loess samples were performed at natural water content, flooded with water, and flooded with a nonaqueous phase liquid (NAPL), such as kerosene. Numerical models were developed to reproduce and analyze the experimental results. The results show that the extended basic Barcelona model (EBBM) can successfully represent the stress–strain behavior of the soil under zero-lateral displacement conditions, as well as the higher compressibility developed by the specimens flooded with water than with kerosene. The presence of kerosene on tested loess produced negligible changes in swelling indexes and was not able to trigger collapse. The effect of particle–fluid interaction on the obtained results is discussed and analyzed to identify the main responsible mechanisms for soil collapse.