Numerical Simulation Of Floor-to-floor Joint Behaviour For Progressive Collapse

Numerical Simulation of Floor-to-Floor Joint Behavior for Progressive Collapse Resistance Design in Precast Concrete Cross Wall Structures

In precast concrete cross wall structures, the prevention of progressive collapse often utilises four types of alternate load path, i.e. catenary, cantilever, vertical, and diaphragm actions that the undamaged structures can provide. The study reported in this paper includes a numerical simulation of the catenary action in floor-to-floor assemblies. This load path is facilitated through longitudinal ties embedded in the cast in-situ grout contained in the keyways of floor slabs. A series of three-dimensional finite element models of the pullout behaviour of strand in keyways were developed. This was added by another series of three dimensional non-linear analyses to simulate the behaviour of floor to floor connections in the absence of underlying wall support using the "alternate load path" method. To simulate the steel-concrete interaction, an element called as "Translator", a type of interfacial connector built in ABAQUS, is used.

The numerical results were very close to the pullout and full scale experimental results undertaken by Portland Cement Association (PCA). Discrepancies in the tie force between the numerical and codified specifications have suggested an underestimate of TF method; hence an improved TF method has also been proposed to address this concern.