Experimental Study on the Combined Effect of Polymeric Modifiers and EPS Particles in Suppressing Frost Heave of Silty Clay

The artificial ground freezing method is a well-established support technique with excellent water-sealing and reinforcement effects. However, the frost heave effect induced during its practical application has become a critical issue restricting engineering safety. Effectively mitigating frost heave is a key technical challenge for its successful implementation. This study focuses on active soil modification techniques by introducing novel stabilizing materials, including polyacrylamide (PAM), polyvinyl alcohol (PVA), sodium lignosulfonate (SLS), and expanded polystyrene (EPS) particles. The inhibitory mechanisms and synergistic effects of these materials on the frost heave behavior of silty clay were systematically investigated. The results indicate that: PAM and PVA form a three-dimensional cross-linked network structure, significantly restricting moisture migration and ice crystal growth, thereby reducing the frost heave rate by 8.95%~66.28%. As an organic surfactant, SLS effectively improves soil dispersibility, reduces the capillary water migration rate, and enhances the soil's resistance to frost heave. The inhibition rate exhibits a parabolic trend. EPS particles mitigate frost heave through pore structure reconstruction and stress buffering effects, achieving a 50.71% inhibition rate at a 0.02% dosage. Notably, the combination of PVA and EPS exhibits a synergistic enhancement, increasing the frost heave inhibition rate to 77.43%, which is 52.69% higher than that achieved with EPS alone. This mechanism stems from the formation of composite agglomerates between the polymer hydrogel and EPS particles, which simultaneously enhance soil cohesion and the dissipation of frost heave stress, thereby improving resistance to frost heave deformation. This study proposes an innovative composite modification system integrating polymer modifiers with EPS particles, systematically investigates their synergistic effect on mitigating frost heave in clayey silt, and offers technical guidance for practical engineering applications.