Sabkha soils, widespread in Egypt's coastal arid zones such as Eastern Port Fouad, present severe geotechnical challenges due to their high salinity, low bearing capacity, and collapsible structure. Building on the limited regional research addressing these deposits, this study experimentally evaluates the stabilization of Sabkha soil using an acrylic copolymer (5S-Road) as a sustainable chemical treatment. A detailed characterization of the untreated soil-encompassing geotechnical, chemical, mineralogical, and microstructural analyses-classified it as a highly saline silty clay with total dissolved solids of 9.63%, low undrained shear strength (36.45 kPa), and high compressibility index (0.344). The experimental program focused on one-dimensional oedometer tests to assess the effects of various copolymer application techniques-grouting, mixing, surface coating, and hybrid mixing-coating-relative to untreated and mechanically compacted control cases. Notably, the compaction control exhibited anomalous expansion under load due to salt recrystallization and osmotic effects, confirming that mechanical densification is ineffective for saturated Sabkha soils. In contrast, copolymer-treated specimens demonstrated significant improvements in stiffness and compressibility, with the compression index reduced by nearly 45% and the preconsolidation pressure more than doubled. A Monte Carlo Simulation framework was implemented to assess probabilistic reliability, demonstrating close agreement with experimental data and reduced variability in key compressibility parameters. The integrated deterministic-probabilistic approach confirmed that acrylic copolymer stabilization not only enhances soil stiffness and stability but also improves engineering predictability, offering a practical and reliable solution for foundation improvement in saline coastal environments.