Analyzing Influencing Factors and Predictive Modeling of Dynamic Resilient Modulus for SAP-Treated Loess Subgrade

The dynamic resilient modulus of subgrade soil is a critical parameter in flexible pavement design, reflecting the stiffness of the subgrade material. The cyclic triaxial tests were carried out to investigate the variation of dynamic resilient modulus of superabsorbent polymer (SAP)-treated loess under various influencing factors. The results indicated that dynamic resilient modulus of SAP-treated loess decreased with increasing moisture content and deviatoric stress, while it increased with higher confining pressure and compaction degree. The relative influence of factors on dynamic resilient modulus of SAP-treated loess subgrade ranked as follows: moisture content > confining pressure > compaction degree > deviatoric stress > SAP content. Based on the NCHRP1-28A model, a prediction model for dynamic resilient modulus was developed. The prediction model shows strong agreement with the experimental data, indicating its potential as a reliable and simplified approach for assessing dynamic resilient modulus in SAP-treated loess subgrade design.