A simplified model of catenary action in reinforced concrete frames under axially restrained conditions

From previous experimental studies on missing column scenarios, catenary action could provide beneficial effects on structures during load redistribution after a target column is suddenly removed under an alternative load path procedure to assess structural resistance to progressive collapse. However, full-scale structural tests are costly and time consuming. Equally, finite-element models require in-depth expertise and large computing resources. Practising engineers are not amenable to this approach for preliminary sizing of members or for a quick assessment of structural resilience. To address this need, this paper provides a simplified semi-analytical model for predicting structural response under a column loss scenario. The model is constructed based on finite-element simulations and is verified by test results. The simplified model idealises the structural response of reinforced concrete beam–column sub-assemblages under column loss scenarios as a piecewise multi-linear curve. It shows good agreement with published test results and validated finite-element simulations.