Linear seismic response of arch dams to non-uniform excitations considering load combination effects

In the present paper, the effect of non-uniform excitation due to spatially varying earthquake ground motions(SVEGM) on linear responses of concrete arch dams is investigated. An iterative scheme is utilized to generate seismicground motion time-histories at several locations along foundation boundaries that are compatible with prescribedtarget response spectra and are correlated according to a given coherence function including the wave propagationeffect. A double curvature arch dam is selected as case study in which the reservoir is modeled as a compressiblemedium and the foundation is assumed to be massless. Various load combinations are considered based on thecorresponding reservoir water levels and thermal loads. It is observed that using SVEGM leads to higher values in bothtensile stresses and percentage of overstressed parts within the dam body in comparison with uniform excitation andtherefore to be more realistic in calculating the dam response, this phenomenon should be incorporated in seismicanalyses especially in high seismicity regions.

Keywords:

Arch dam , linear analysis , non-uniform excitation , SVEGM