<p>The study concludes that salt–clay interactions, especially under long-term loading, alter the mechanical response of clay soils not only structurally but also by influencing time-dependent parameters crucial for design in geotechnical engineering. Building on this premise, the research investigates the influence of pore water salinity on the time-dependent deformation behavior of soft clay soils, focusing on both primary consolidation and secondary compression. While the effect of salinity on consolidation behavior has been widely examined, its impact on secondary compression remains limited in the literature. To address this gap, a series of oedometer tests were conducted using reconstituted high- and low-plasticity clays prepared with NaCl and CaCl₂ solutions at varying molarities (0–2&#xa0;M). SEM imaging was employed to observe salt-induced fabric and structural changes. The findings reveal that increasing salt molarity and cation valency shorten the diffuse double layer (DDL) thickness, promote flocculation, and reduce compressibility, thereby accelerating the transition from physicochemical to mechanical control in load-bearing behavior. In high-plasticity clays, salt exposure significantly increases preyielding and threshold stresses due to thixotropic aging effects, and strong correlations are observed between both the compression index (Cc) and secondary compression coefficient (Cα) with the liquid limit (LL). These results demonstrate the importance of considering physicochemical interactions in evaluating the long-term mechanical behavior of clayey soils under saline conditions.</p>