The seismic response evaluation of concrete gravity dams requires special attention due to the unique characteristics of these massive structures: (i) they are long structures located at complex sites, and hence, the spatial variability of seismic ground motions plays a significant role; (ii) dam-reservoir foundation (rock) interaction is an important component of the structural response; and (iii) due to the sizable fracture process zone in concrete, and, especially, the large aggregate concrete used in the construction of these structures, their non-linear constitutive modeling is not yet fully quantified. Even though it has been clearly recognized that the spatial variation of seismic ground motions cannot be neglected in the seismic response analysis of dams, no evaluation of this effect on concrete gravity dams has been conducted. This exploratory SGER proposal addresses, for the first time, the issue of incorporating the spatial variation of seismic ground motions in the response evaluation of concrete gravity dams, and conducting sensitivity analyses of the effect of spatial variability on the response of these massive structures. It proposes a compromise between accurate modeling and computational effort in an initial attempt to evaluate the response of concrete gravity dams subjected to a wide range of non-uniform seismic excitations and to quantify the effect of spatial variability. The modeling approximations will consider either a more complex structure in a simpler topographic setting or a simpler structure in a more complex topographic setting. The seismic ground motions will be recorded data at depth (representative of recordings of earthquakes with magnitudes up to 8.0) that will serve as the "reference" ground motions, from which spatially variable ones will be generated. The results of this effort can then be used as "seed" in future studies for the selection of critical non-uniform input motion features for the response evaluation of detailed models of concrete gravity dams in complex settings.
