Computational assessment of the progressive collapse of reinforced concrete planar frames using a nonlinear multilayered beam formulation

Resumen

This work investigates the response of two reinforced concrete (RC) planar frames after the loss of a column and their potential resistance for progressive collapse (PC). Nonlinear dynamic analysis is performed using a multilayered Euler/Bernoulli beam element, including elasto-viscoplastic effects. The material nonlinearity is represented using one-dimensional constitutive laws in the material layers, while geometrical nonlinearities are incorporated within a corotational beam formulation. The frame models were designed in accordance with the minimum requirements proposed by fib [1-2], Eurocode 2 [3], and NBR 6118 [4]. The load combinations considered for PC analysis follow the prescriptions of DoD [5]. The work aims at verifying if the minimum requirements of the considered building codes are sufficient for enforcing structural safety and robustness, and also points out the major differences in terms of PC potential of the corresponding designed structures.