Progressive collapse of building structures typically occurs when an abnormal loading condition causes a sudden loss in the structural capacity of one or more critical members, which leads to a chain reaction of failure and ultimately a catastrophic collapse. It is well accepted that in order to prevent the progressive collapse of beams or slabs, the establishment of catenary action mechanism is crucial to attain adequate post-collapse resistance. Experimental, numerical and analytical studies have been conducted to investigate the catenary behavior of the precast concrete slab system following the removal of their intermediate wall supports. Results also reveal that for the ties designed with inadequate embedment length, the slip and the resulting large deflection will effectively trigger the catenary action. However, the full bond will limit the development of deflection and lead to the fracture of tie bars before the catenary action is trigged. An improved TF model using numerical analyses was proposed to design the floor-to-floor joint against the progressive collapse in precast cross wall structures, which shown a close agreement with the DoD 2013 regulations.
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