Linear elastic and plastic-damage analyses of a concrete cut-off wall constructed in deep overburden

Asphalt concrete core dams (ACCDs) are becoming more widely used worldwide. ACCDs with concrete cut-off walls (for controlling foundation seepage) have been constructed in deep overburden. It is important to assess dam safety by analysing the stress and deformation behaviour of the concrete cut-off wall. In this study, a 3D finite element (FE) procedure was developed to simulate the dam construction and water impounding processes of an ACCD. Rockfill/gravel materials were described using a Duncan-Chang model, and the interface between the concrete cut-off wall and the foundation gravel was modelled using interfacial elements that follow a tangential hyperbolic stress-strain model. The linear elastic and plastic-damage models were employed to model the concrete cut-off wall. The stress-deformation behaviour and the damage distribution of the concrete cut-off wall were numerically simulated and analysed. The results indicate that the plastic-damage model was more reliable than the elastic model in describing the mechanical behaviour of the concrete cut-off wall. The plastic-damage model can be used to evaluate the safety of concrete cut-off walls constructed in deep overburden.