Research on the State-Dependent Hyperbolic Model of the Interface between Spoil Mixture and Concrete

ABSTRACT A series of large-scale direct shear tests were carried out to study the stress-strain relationship of the interface between the spoil mixture and concrete under different roughness conditions. The results showed that roughness significantly affects the shear strength properties and dilatancy characteristics of the interface. Under different roughness conditions, the shear stress ratio and the normal deformation of the interface tend to be stable after larger shear strain, and the interface presents the characteristics of a critical state. With the increase of shear strain, the void ratio of the interface shows the law of transformation from the initial void ratio to a certain stable void ratio. Based on the void ratio prediction formula of the interface, the relationship between roughness and critical state parameters was established, and the interface state parameters were introduced into the hyperbolic model. Finally, a state-dependent hyperbolic model of the interface considering the roughness was established. Importantly, the model can well reflect the shear stress-strain relationship of the interface under different roughness conditions.