Engineers encounter difficulties when building infrastructure due to heavy settlement and low bearing capacity of soft clay. Reducing pavement thickness becomes feasible and construction costs decrease when the subgrade exhibits higher resistance to deformation. This study focuses on utilizing nano-silica as a stabilizing agent in soft soils to enhance their strength and durability. A finite element approach using ABAQUS software was employed to evaluate the strain behaviour and rutting performance of the subgrade. Input parameters were sourced from previous research involving Unconfined Compressive Strength (UCS) tests with varying nano-silica contents. The Mohr-Coulomb theory was used to model the subgrade in order to simulate the elasto-plastic reaction. UCS results showed that soil treated with 3%, 5%, 7%, and 9% nano-silica yielded strengths of 99, 190, 280, and 294.46 kPa, respectively, with 7% identified as the optimal content. Simulations in ABAQUS demonstrated the deformation characteristics of both natural and treated soils, highlighting the significant influence of subgrade properties on pavement deflection. The findings confirm that nano-silica effectively enhances subgrade performance by minimizing deformation and increasing shear strength.