the effect of spatial correlation of horizontal and vertical spectral accelerations on seismic performance of a bridge network

Quantifying the spatial correlation of ground-motion intensity measures (ims) is necessary for assessing the seismic risk of lifeline networks (for example; transportation, electricity, gas, telecommunications, water supply) and building portfolios. many ground motion prediction equations (gmpes) have been developed to estimate ims as a function ofearthquake magnitude, source-to-site distance and variables such as local geological conditions at a single site. these include peak ground acceleration (pga), peak ground velocity (pgv) and spectral acceleration (sa). however, gmpes do not consider the spatial correlation of ground motion ims among sites for a given earthquake event. however, it hasbeen shown that the effect of spatial correlation on seismic risk assessment of spatially-distributed systems is significant and that ignoring or overestimating this may overestimate frequent losses and underestimate rare losses (bastami, 2007).