Investigation of damping in arch dam-water-foundation rock system of Mauvoisin arch dam

The overall damping of linear arch dam-water-foundation rock systems depends on the material damping of dam concrete, the material and radiation damping of semi-unbounded foundation rock, and the dam-water interaction. In this paper, the effective damping ratio of these factors is separately evaluated for Mauvoisin arch dam in Switzerland to quantitatively discuss their contributions, and to guide the damping selection in the numerical analysis. This paper also aims to investigate if the material and radiation damping of the foundation rock can be replaced by increasing the material damping of the dam to simplify numerical analysis models. The seismic responses of Mauvoisin arch dam are analyzed using the semi-unbounded and massless foundation models, respectively. The results show that the overall effective damping ratio of the system can be approximately expressed as the summation of the individual effective damping and thus the increased material damping of the dam can approximate the material and radiation damping of the semi-unbounded foundation rock.