Experimental study on dynamic characteristics of reinforced loess under small strains

Abstract

This study investigates the water-induced damage of loess subgrades in Northwest China through resonant column tests, with a focus on the effects of reinforcement type, reinforcement spacing, and confining pressure on the dynamic shear modulus. Results demonstrate that the inclusion of geosynthetic reinforcements significantly enhances the dynamic shear modulus of the composite soil. Among the tested reinforcement configurations, the triaxial geogrid system exhibits the most pronounced improvement. The normalized dynamic shear modulus follows a nonlinear decay trend with increasing shear strain, consistent with conventional attenuation curves. Higher confining pressures or reduced reinforcement spacing effectively delay the modulus degradation, mitigate hysteresis effects, and improve the overall stiffness characteristics of the reinforced loess.The findings confirm that geosynthetics can enhance the dynamic performance of loess, providing a vital theoretical basis for the seismic design of loess subgrade engineering.