Analytical and Field Evaluation of Dynamic Propertiesfor an Orthotropic Deck Bridge

Making assumptions and simplifications are generally acceptable in structural modeling,leading to approximations in structural analyses results. Furthermore, these assumptions mayinfluence calculated dynamic properties of bridges and lead to significant errors. One of themost common assumptions which simplify the dynamic solution of bridges is assuming passingtraffic as moving loads. Masses and suspension systems of passing vehicles affect trafficinduced deck vibration even some dynamic properties of the bridge, especially where thebridge deck weight is relatively low compared with moving loads. Field tests are occasionallythe only reliable approach for obtaining comprehensive perspective of the real dynamic behaviorof a bridge. In this article, induced vibration of an orthotropic deck bridge with 24 metersspan is studied through field tests with passing standard vehicles. Moreover the bridge isanalyzed both as a beam under moving loads and moving masses. Results of closed form analyses are compared with field tests results to evaluate accuracy of simplifying assumptions.

Keywords:

Dynamic properties of bridges , Moving loads , Field test , Moving mass