Development of an Experimentally Validated Analytical Model for Modular Bridge Expansion Joint Behavior

Modular bridge expansion joints (MBEJ) are large-capacity systems placed between two superstructure segments designed to provide safe joint crossing based on anticipated bridge movements. Locations of discontinuity in bridges are often recognized as weak links and therefore characterizing the behavior of expansion systems installed at deck joints under various excitations is critical to support the forecasting of bridge functionality. This paper presents the development of an analytical model representative of a common modular bridge expansion joint including its critical components, such as friction elements, equidistant devices, support bars, and center beams. The model is then validated through full-scale experimental testing of the joint. The results of this study offer a predictive model for the longitudinal motion of bridge joints excited through anticipated service or extreme events, which can be used to help determine local and global failure within the joint and make inferences as to how a bridge system could be affected. Such models provide a key step toward aiding design efforts, enabling more accurate specification of MBEJs, and supporting functionality-based risk assessment for bridges. (C) 2014 American Society of Civil Engineers.