Research on Dynamic Characteristics and Modulus Attenuation Evolution of Rubber Particle Loess.

Loess in seasonally frozen regions is prone to water-induced softening and dynamic instability, posing severe challenges for geotechnical engineering. Rubber particles, as sustainable waste-tire-derived material, offer potential for loess improvement. This study aims to elucidate the dynamic characteristics and modulus attenuation evolution of rubber particle-loess mixtures under multi-factor coupling effects. Dynamic triaxial tests were conducted to investigate the influences of rubber content, particle size, moisture content, and freeze-thaw cycles. Results reveal that the optimal mix is 5% rubber content with 40-mesh rubber particles, which yields the highest dynamic strength (i.e., the maximum dynamic stress that can be sustained before failure). The dynamic constitutive relationship follows the Hardin-Drnevich hyperbolic model. Increased moisture content and more freeze-thaw cycles reduce the maximum dynamic elastic modulus and strain, while higher confining pressure enhances them. A dynamic elastic modulus attenuation model was established to characterize strain-softening behavior. These findings clarify the dynamic response mechanisms of modified loess, providing a theoretical basis for its engineering application in seasonally frozen regions.