Probabilistic assessment of the ultimate load-bearing capacity in laterally restrained two-way reinforced concrete slabs

In the last two decades, the problem of compressive membrane action (CMA) in laterally restrained reinforced concrete (RC) slabs has been widely under research due to significant strength enhancement and reserve strength it can provide in resisting progressive collapse. Besides, it is well known that reliability of a structure subjected to extreme loading scenarios is a function of uncertainty propagation in the ultimate load-bearing capacity of structural components. This paper is concerned with probabilistic assessment of the ultimate load-bearing capacity of laterally restrained RC slabs considering the contribution of CMA. Using global variance-based sensitivity analysis, uncertainties in material properties, geometrical properties and mechanical properties are studied. Moreover, the influence of different modeling strategies on uncertainty propagation is investigated for the available analytical and numerical approaches to provide a basis in terms of probabilistic model quality. Mesh sensitivity and parametric studies are also performed to shed light on the influence of finite element discretization, reinforcing steel configuration, and in-plan aspect ratio on uncertainty propagation in the ultimate load-bearing capacity. Following the sensitivity studies, non-influential parameters are fixed at their mean values, and the probability of failure is estimated for the investigated modeling strategies using a full-probabilistic approach.