The second generation of Eurocode 8: comparison between the new displacement-based and force-based design approaches for RC MRFs

This work compares the force-based (FB) design of moment resisting frames, as proposed in the next generation of Eurocode 8, with a complete displacement-based (DB)design approach, also introduced in the future code. After describing some of the evolutions in the FB approach, namely regarding the use of behaviour factor components, the main concepts of the DB approach are addressed, including the associated global and local verifications. The FB design of a set of reinforced concrete frames is described, followed by their nonlinear static analyses and DB-like verifications. These results are used to estimate the components of the behaviour factor, which are then compared with those adopted initially for the FB design. The level of conservativeness of the FB approach is estimated by comparing the ratios between the plastic deformation demand and capacity with the target values.