Reliability Analysis of the Simplified Punching Shear Resistance Model of Eurocode 2:2004 in Different Column Positions on Flat Slabs

Resumo

The use of coefficients in structural design is a strategy aimed at providing adequate levels of safety for buildings, avoiding excessive conservatism. The effectiveness of these coefficients depends on mathematical models that approximately capture the real behavior of the structure, considering the random nature of resistance and load variables. In this context, the proper definition of coefficients is even more crucial in resistance models that do not have an analytical formulation, such as empirical models. An example of an ultimate limit state whose model is empirical is the punching shear phenomenon, which occurs in flat reinforced concrete slabs. Despite the notable accuracy among normative models to assist in the development of these phenomena, some are based on simplifications that can result in high levels of conservatism or even insecurity when compared to more refined models. In EUROCODE 2:2004, there is the possibility of omitting the analysis of moments in the slab-to-column connection in punching shear design, considering only the axial force. For this purpose, a coefficient is applied to the applied stress to compensate for this simplification, depending on the position of the column in plan: corner, center, or edge. Therefore, this research aims to evaluate the reliability, through the First Order Reliability Method, of slab-to-column connections subjected to punching shear, using the EUROCODE 2:2004 simplification for design and employing an error model in the reliability analysis based on stress estimates derived from Fourier series. The research aims to assess whether the reliability indices of these connections demonstrate adequate levels of safety, using as reference the target reliability indices of other recognized standards, such as ACI 318 (2019) and CEB-FIP/MC (2010).