Increasing the size of the floor beams was found not to have significant effect on mitigating progressive collapse, while the use of diagonal bracings in the ground floor or rigid tie beams connecting the structure’ footings was found to efficiently prevent progressive collapse. With diagonal bracings or rigid tie beams, the excessive differential settlements of the footings can be eliminated and the gravity loads can follow a safe alternative path preventing the structural collapse. The tie beam reinforcement was found to have a significant effect on the structural behavior during such an extreme loading case. Section analysis of the tie beam suggests that its ultimate strength should be based on rupture of main reinforcement, which is more economical and appropriate for such loading case.
Hamed, S. Computer-Aided Design of Framed Reinforced Concrete Structures Subjected to Flood Scouring. Journal of American Science 2011;7(10):191-200]. (ISSN: 1545-1003). http://www.americanscience.org.