Nonlinear dynamic characteristics and unified parameter prediction of weakly and strongly cemented soil-rock mixture

The dynamic characteristics of cemented soil-rock mixtures (SRM) vary depending on their material composition, cementation types, and loading conditions. Large-scale undrained strain-controlled dynamic triaxial tests on cylindrical specimens of weakly and strongly cemented SRM were conducted to investigate how their dynamic behaviors responded to changes in cementation types, rock block content (Rc), and confining pressure (Pe). The unified parameter prediction formulas of dynamic shear modulus (G) and damping ratio (λ) were developed. The results showed that the hysteretic stress-strain curves of weakly and strongly cemented SRM changed with the increase of Rc and Pe, following opposite trends (symmetry and asymmetry, separately) due to increasing cementation. The maximum dynamic shear modulus (Gmax) increased linearly with Rc and non-linearly with Pe. The reference shear strain decreased linearly with Rc but increased non-linearly with Pe. The G/Gmax of strongly cemented SRM was relatively higher than that of the weakly cemented case under the same conditions. Their growth law of λ was the opposite. The unified multi-parameter prediction formulas for G and λ were proposed for cemented SRM. This study could enrich the cognition of the dynamic characteristics of cemented SRM.