Abstract:The dynamic shear modulus and damping ratio of silty clay are important parameters for evaluating the dynamic stability of building sites on the Eastern Henan Plain. To analyze the dynamic characteristics of silty clay on the Eastern Henan Plain, we conducted a dynamic triaxial test of the silty clay using a bidirectional-vibration triaxial test system. We also studied the influence of the state and consolidation pressure of silty clay on its dynamic shear modulus and damping ratio. The results indicate that the changes in the dynamic characteristics of plasticized silty clay (PSC) and soft plastic silty clay (SSC) are similar, with increases in shear strain, their dynamic shear modulus ratios decrease, and the damping ratios increase. Under the same strain, the dynamic shear modulus ratio of SSC and the damping ratio of PSC increase with increases in the consolidation pressure. Under the same test conditions, the maximum dynamic shear modulus of PSC was found to be greater than that of SSC. The dynamic shear moduli of PSC and SSC decrease rapidly when the shear strain is less than 0.01%, and tend to be consistent with each other when the shear strain reaches 0.03%. According to existing research on the dynamic shear modulus and damping ratio of silty clay, combined with experimental data, we propose a mathematical model for the dynamic shear modulus ratio and damping ratio of silty clay with shear strain. The results of this study provide a basis for evaluations of dynamic stability at silty-clay construction sites on the Eastern Henan Plain.
