The large spatial variability that is observed in strong ground motion has significant effects on the seismic response of structures such as dams and bridges that are supported on large foundations. The authors have formulated and tested a site-specific procedure for the estimation of spatial incoherence of strong ground motions. The procedure entails the estimation and combination of two contributions to spatial incoherence. One contribution represents the effect of a nearby extended source, which causes interference between simultaneous arrivals from different regions of the fault. It is estimated from closely-spaced simulated acceleration time histories of design basis earthquakes. The other contribution represents complex aspects of wave propagation and local site response that are not modeled in the simulations.
|Number of pages||15|
|Journal||Geotechnical Special Publication|
|Publication status||Published - 1988|