<p>This study investigates the improvement of Tunis soft soil using a single plastic-waste column installed at a low area replacement ratio of 3.7% and a slenderness ratio of 10.42. An integrated experimental and numerical approach was adopted to evaluate the consolidation behavior and settlement response of the reinforced system. Laboratory characterization of the natural soil was first performed, followed by oedometer consolidation tests on unreinforced and reinforced specimens under vertical stresses ranging from 25 to 200&#xa0;kPa. The results demonstrate that the inclusion of the plastic-waste column significantly enhances consolidation performance. Reinforced specimens exhibited a 20–40% reduction in consolidation time and up to 65% reduction in final settlement, depending on the applied stress level. These improvements result from two complementary mechanisms: enhanced radial drainage, which accelerates pore-water pressure dissipation, and stress redistribution within the soil–column composite, which increases stiffness and limits deformation. Numerical simulations performed using PLAXIS 2D were conducted with the Soft Soil Model (SSM) and Modified Cam Clay (MCC) model for the clay, while the plastic-waste column was modeled as a linear elastic material. The SSM provided predictions in close agreement with the experimental results, confirming the reliability of the adopted modeling strategy. Overall, the findings highlight the effectiveness of plastic-waste columns as a cost-efficient and environmentally sustainable ground-improvement technique for soft clay soils.</p>