Previous research on progressive collapse of structures has mainly focused on blast and/or abnormal loadings. Progressive collapse behaviour of structures, especially bridges, caused by earthquake loadings is not as well understood. This lack of information is also reflected in the lack of specific provisions or recommendations in current codes and standards on seismic design of structures. In order to design safer structures against earthquakes and to come up with more cost effective retrofit strategies for the vast number of existing old and often deteriorated bridges in today’s bridge stock, it is important to have a complete understanding of the progressive collapse behaviour of structures from initial failure of individual structural members, progression of the damage and degradation of stiffness and strength, to ultimate collapse of the system.

This thesis presents results of a study on earthquake response analysis of bridges by using the Applied Element Method that allows separation of structural members or components due to fracture failure, and the effects of contact and inertial forces caused by the falling debris. The analysis is able to predict the initiation of collapse, progression of collapse, and the final collapse mechanisms. Understanding of the progressive collapse behaviour of structures can lead to a better and more effective design and retrofit strategy for earthquake resistant design of structures. The results show that collapse of single structural component of the bridge can have significant ramification effect that can drastically change the behaviour of the entire bridge system in a process that is not well understood before. The analysis outputs also give information on the structure’s condition during and after earthquakes so that more effective performance-based design retrofit strategies can be devised by taking into account the expected damage of the structure.

H. Wibowo (2009), Progressive Collapse Analysis of Reinforced Concrete Bridges During Earthquakes, Masters Thesis, Department of Civil & Environmental Engineering, Carleton University, August 2009.