Punching Shear Failure in Progressive Collapse Analysis

A column failure caused by an explosion, impact, or other accidental events can propagate in a flat plate/slab structure through punching shear and lead to progressive collapse. The local post-punching behavior of flat slabs has been investigated experimentally and theoretically at the EPFL, Switzerland, and a mechanical model capable of predicting this behavior was developed. Using the mechanical model, an analytical model is developed here to estimate the initiation of punching shear failure as well as post-punching shear response of flat plates/slabs. The analytical model is used to study the system level post-punching response of structures and nonlinear dynamic finite element analyses are performed using a general purpose finite element software ABAQUS. The analytical model and the results of system level study can be of interest in assessing progressive collapse resistance of existing structures and in design of new structures.