Insights into the effect of spatial variability of recorded earthquake ground motion on the response of a bridge structure

With the aim of evaluating the effect of spatial variability of recorded ground motions on spatially extended structures, we present a numerical study on the linear and nonlinear response of an idealized integral-abutment bridge, subject to the 2004 Parkfield recordings at the UPSAR array. The results show that spatial variability of recorded motion may present features which are poorly predictable by standard coherency approaches and this may have a considerable impact even on a regular, 300-m long structure on homogenous stiff soil conditions, leading to localized increase or decrease of engineering demands parameters up to a factor of about 50%.