Influence of fluid structure interaction on a concrete dam during seismic excitation

The aim of this study is to investigate how Fluid-Structure interaction may be included in numerical earthquake analyses of dams. The basis for this project is theme A from ICOLDs 12th international benchmark workshop on numerical analysis of dams, which was held in October 2013. The focus of theme A was on how to account for fluid structure interaction in numerical earthquake analyses of dams. In this study, parametric numerical analyses have been performed where the purpose was to isolate some important parameters and investigate how these influence the results in seismic analyses of dams. These analyses were performed through the use of the finite element methodare the choice of Rayleigh damping parameters, reservoir boundaries and wave absorption in the foundation-reservoir interface. The use of acoustic elements has proven to be a powerful approach for FSI analyses of adam-reservoir-computation time, while allowing for more advanced features such as bottom absorption and non- be a challenging task, where it has a significant impact on the results. The method proposed by Spears and Jensen has a physical meaning in the sense that this method excites the same e ective mass for the Rayleigh damped case as for the modal damped case. If a constant modal damping is desired or prescribed in a standard, this method provides a reasonable and sound method to choose the Rayleigh damping parameters for a complex structure. A more straightforward method is to choose the two frequencies in such a way that the span between the frequencies covers about 80% of the e ective mass. The choice of reservoir boundary conditionsparameter showed to be the one that least a ected the results in the time-history analysis. results and this coe cient should be used carefully.QC 20190729