Performance Based Seismic Design for Movable Bridges

Performance based design can be defined as a design approach exclusively developed in order to have the bridge structure meet targeted performance goals for range of hazard levels. The design is primarily focused on meeting various performance objectives that are in line with the desired level of the service of the structure. Seismic performance criteria establish the safety and functional performance of the bridges after an earthquake. Movable bridges are an expensive key part of the transportation infrastructure and are usually irregular and asymmetrical in geometry and support conditions. Therefore it is important to have performance-based design as they present unique challenges and are required to be evaluated not only for stresses but also more importantly their performance. This should require the designers to deal with functionality of the complex connection of movable component and stringent mechanical tolerance that needs to be complied in the design of movable bridges to reduce losses after the seismic events.