Enhancing mechanical characteristics of a collapsible sandy Sabkha soil using an eco-friendly admixture: An experimental and numerical study

ABSTRACT The aim of the present research is to improve the mechanical characteristics of a continental collapsible Sabkha soil using eco-friendly lime content under structures. The experimental portion is performed on both treated and untreated saturated collapsible soil, focusing on compaction characteristics, collapse potential, shear strength, and California bearing ratio (CBR). Full-scale three-dimensional numerical models are built for a footing that rests on untreated and treated collapsible soil with different lime contents under immersion conditions. The results indicate that increasing lime in collapsible soil causes incremental improvements in the maximum dry density. Furthermore, lime stabilization effectively reduces the collapse potential of the studied soil, while increasing lime content in the soil leads to a greater reduction in the collapse potential, with a 20% lime content completely resolving the collapse problem. Increases in lime content also contribute to important increments in shear strength parameters and CBR values. Moreover, the shear strength of the stabilized soil with 20% lime increases to more than six times that of the untreated soil. The improvement in the mechanical properties of the stabilized soil is found to persist over time. Numerical analyses results also show that lime stabilization significantly increases the allowable bearing capacity of the soil. Consequently, the stabilized soil with 20% lime content increases the allowable bearing capacity to more than seven times that of the untreated soil, effectively reducing settlement of the footing.