The Influence and Optimization of Treatment Strategy in Enhancing Semiarid Soil Geotechnical Properties

In this article, the effect of randomly oriented polypropylene fiber inclusion in enhancing the various geotechnical properties (unconfined compression strength, compressibility index, swell index, hydraulic conductivity, linear shrinkage, California bearing ratio) of a typical expansive semiarid soil is studied. Since the practicing engineer typically has difficulty in selecting the right mix of fiber type, dosage, and lime content to meet the optimum requirements of this targeted group of geotechnical properties, PROMETHEE is here adopted in order to assist in the decision-making process. The primary objective of this study was to evaluate different geotechnical properties for possible alternatives, the first being untreated soil itself and the second treating the soil with 6% lime. The remaining alternatives vary with fiber type, fiber size, and fiber dosage with or without lime. A further objective was to study the combined influence of factors, viz. lime addition, fiber type, fiber dosage, and fiber length at their respective levels of interactions for the targeted soil properties. The results of the study led to the identification of groups of criteria expressing similar preferences. Sensitivity analysis was carried out in order to better understand the conflicts to be solved in order to make this decision.