Stochastic response of concrete faced rockfill dams including partially ice-covered reservoir-foundation interaction under spatially varying seismic waves

摘要

In this study, a linear finite element method which considers viscous boundaries is presented to investigate the effect of the presence of ice cover on the stochastic seismic response of concrete faced rockfill (CFR) dam-reservoir-foundation interaction systems when subjected to spatially varying ground motions. For the spatially varying ground motion, the wave passage effect is included while neglecting the effects of variable soil conditions and loss of coherency. The partially ice-covered reservoir-dam-foundation interaction system is modeled by the Lagrangian (displacement-based) fluid and solid-quadrilateral-isoparametric finite elements. As a numerical example, Torul dam coupled interaction system is investigated for the horizontally applied east-west component of the Kocaeli earthquake ground motion. The ground motion is described by the filtered white noise model and applied to each support point of the two dimensional finite element model of the ice-dam-reservoir-foundation system. A parametric study is carried out to evaluate the effects of the ice cover on the stochastic behavior of the concrete slab of the coupled dam system for variable water level in the reservoir and cracked ice cover. The effect of the ice cover on the stochastic response of the concrete slab with variable thickness is also examined in the study for seismic excitation. It is outlined that the ice cover effects must be considered in the stochastic analyses of CFR dams when subjected to spatially varying ground motions. A parametric study is conducted to investigate the effects of water level in the reservoir (with ice cover and cracked ice cover) on the stochastic behavior of the concrete face slab.