Dynamic deformation characteristics of EPS particles lightweight soil based on Ramberg–Osgood model
摘要
To explore the dynamic deformation characteristics of expanded polystyrene (EPS) particle lightweight soil under dynamic loads, based on the Ramberg–Osgood (R-O) model with variable parameters, we extracted the parameters through dynamic triaxial test results for lightweight soil. Thus, the variation laws and applicable ranges of the model parameters R and α1 with the dynamic shear strain (γd) of the lightweight soil were obtained. The influences of the EPS particle content, cement mixing ratio, and confining pressure on the model parameters were analyzed. The applicability of the R-O model to lightweight soil was verified by changing the stress state and stress path in the dynamic triaxial tests. The results reveal that the range of R applicable to lightweight soil under dynamic loads is (1, +∞) and that α1 should be considered within the range of effective γd. When γd is less than 1×10−3, R of the R-O model with variable parameters for lightweight soil decreases rapidly and subsequently tends to remain stable with an increase in γd; the stable value range of R is (1, 2). Further, when γd is less than 1×10−3, α1 decreases rapidly and then increases with γd. The damping effect of lightweight soil exhibits two types of curve forms: bell-shaped and S-shaped curves. Notably, the variable parameters of the R-O model can be adjusted with the changes in γd. Thus, this model can adequately describe the variation laws of the dynamic shear modulus ratio and the damping ratio for lightweight soils subjected to complex dynamic loads.