The geotechnical qualities of the soil influence the stability of civil engineering structures. Although clay soil is a varied and challenging material, it is widely utilized in construction due to its availability and low cost. The stabilization of clay soil by incorporating lime and wheat husk ash provides an avenue to improve the behavior of clay soil and also promote environmental sustainability in road construction. The study considered different combinations of lime and wheat husk ash, varying between 0% and 8%, and measured the weight of the dry soil at all percentages. The maximum dry density, consistency limit, California bearing ratio, unconfined compressive strength, and erodibility potential of the stabilized soil were evaluated to assess its performance. The prediction of soil properties using the response surface methodology approach is a novel contribution in this paper. This study uniquely integrates wheat husk ash and lime for prediction modeling of soil properties with good accuracy, as indicated by the coefficient of determination of 0.91, 0.87, 0.86, 0.77, and 0.95 for the maximum dry density, soaked California bearing ratio, unsoaked California bearing ratio, unconfined compressive strength, and erodibility potential, respectively. In addition, the trend of the experimental data was evaluated by visualization using the 2D contour plots of RSM. The plots indicated an optimum content of 2% for WHA and a lime content between 6% and 8% for improved soil performance. Analysis of variance was performed on the experimental data to identify significant terms, and predictive models were validated, with the majority of the experimental data falling close to the model predictions.
