Rubber dams are flexible cylindrical inflatable structures attached to a rigid base and inflated by air and/or water. Due to elasticity of the structure and continuous variation of its shape during operation, a rubber dam structural and hydraulic analysis is more complicated than a rigid dam.

This paper deals with numerical analysis of the rubber dams for solving the flow based problem and static and dynamic structural analysis, simultaneously. The three dimensional fluid–structure interactions are analyzed both under the stationary hydrostatic and overflow conditions, based on different internal pressures, and upstream and downstream water depths. The water free-surface was obtained based on two-phase air–water flow interface. The flow separation downstream of the dam was modeled using shear stress transport turbulence model. The results describing height, cross-sectional profile and cross-sectional area of the dams were compared with these of former studies and good agreement was obtained. Altogether, the fluid–structure interaction analysis provides two new correlations to predict the equilibrium height of the rubber dam and its discharge coefficient based on the dam equilibrium height and the total upstream head. It was found that the rubber dam equilibrium height is a function of its thickness, modulus of elasticity, internal pressure and foot width.