The research on progressive collapse of structures generally focuses on gravity and blastloadings and the design objective is to increase the redundancy and robustness of structures to preventprogressive collapse. Studies of bridges damaged by earthquake in past major earthquakes have shownthat better methodology for earthquake resistant design of new bridges can be developed. Moreover,effective retrofit and strengthening strategies can be devised to enhance the performance and safety ofexisting deficient bridges if progression of damage from initial failure to ultimate collapse, and its impacton the failure mechanisms of structures, is better understood. This paper presents the modelling andanalysis of progressive collapse behaviour of bridges during earthquakes using the Applied ElementMethod that can take into account separation of structural components resulting from fracture failure andcontact or impact forces of falling debris. The results show significant influence of the progressivecollapse phenomena on the performance of bridges during major earthquakes. These also demonstratethe need to consider progressive collapse mechanisms in seismic design performance assessment andevaluation of bridges that would lead not only to a safer and more reliable earthquake resistant design fornew structures but also more effective retrofit and strengthening strategies for older structures.
展开▼
