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Punching shear is a type of failure of reinforced concrete slabs subjected to high localized forces [a]. This type of failure is catastrophic because no visible signs are shown prior to failure [b]. Punching shear failure disasters have occurred several times in this past decade [b]. An example of punching shear failure can be see in image 2.

A typical flat plate punching shear failure is characterized by the slab failing at the intersection point of the column. This results in the column breaking through the portion of the surrounding slab (as seen in image 1). This type of failure is one of the most critical problems to consider when determining the thickness of flat plates at the column-slab intersection. Accurate prediction of punching shear strength is a major concern and absolutely necessary for engineers so they can design a safe structure [b].

Research has also been conducted in the past to develop an understanding of why punching shear occurs and how to prevent it. In recent years, the finite element method has been applied to analyze punching shear failure problems.  It can be used to develop an analytical model for the punching shear failure analysis of reinforced concrete plates [b]. Furthermore, it has been discovered that punching shear can be prevented by increasing the depth of the concrete floor slabs, or by increasing the diameter of the columns supporting the floor [c].

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