Evaluation of bridge damage data from the 1994 Northridge, CA

ABSTRACT

Data on bridge damage from earthquake is becoming incresingly more available. Such data however, have not been systematically studies with the objective to evaluate damage charactistics and to correlate these to observed or estimated local ground motion. This paper presents the results from a project in which bridge damage data from the 1994 Northridge earthquake are studiesd. Structural characteristics that are highly correlated with the observed damage are identified. Bridge are grouped by these structural characteristics and empirical fragility curves are developed for these groups. Only about two percent of the bridges that were exposed to ground shaking experienced damage and only 6 of these bridges collapsed. The analyses od data on bridge damage showed that concrete structures designed/built with older design standards were more prone to damage under seismic loading. (AU)