Constitutive model for interface between concrete slab and rockfill and its application

Concrete slabs play a crucial role in the seepage controlling system of concrete-faced dams. The stress and deformation behavior of concrete slabs mainly depends on the stress-strain properties of their supporting rockfill materials and the contact behavior of the interfaces between slabs and damming rockfill materials. The interface models are commonly used, in stress and deformation analyses of concrete-faced dams, to reflect the load-transferring mechanism between the concrete slabs and the rockfill materials. Therefore, the reliability of the calculated results depends on the rationality of the interface model used. In this study, the deficiency of the traditional hyperbolic interface model is shown, and a new interface model is proposed. The new model can consider the coupling effects between two shearing directions, and the requirements of shear strength criterion and frame-independence are satisfied. The model uses only a few parameters and is easy to implement in finite element analyses. It is shown by a case study that the compressive failure zones occur in real projects can be simulated by the proposed model, at least in a qualitative manner. © 2024 Chinese Society of Civil Engineering. All rights reserved.