Finite Element Modelling of Seismic Fluid-Structure Interaction for a Large Arch Dam

The linear dynamic fluid-structure interaction at seismic loading for the artificially generated large arch dam provided for the Theme A was modelled using the approach of acoustic compressible elements, with both the coarse and fine meshes provided by the formulators of the 12^th ICOLD Benchmark Workshop.

The effects of incompressible fluid (theoretical hypothesis of the added mass models) and of the partial absorption of the hydrodynamic pressure waves at the reservoir boundary (bottom and sides) were also investigated.

Simulations were carried out using the RSE in-house FEM code CANT-SD, specifically designed for dynamic linear and non-linear analyses of dam-reservoir systems. The coarse and fine meshes showed not dissimilar results, except at dam-foundation interface. The results of the analyses confirmed that incompressible models could result relatively conservative and highlighted the benefits of the approach of acoustic elements, mainly the possibility to take into account the damping effect on the fluid boundary.