Robustness assessment of RC buildings by analysis of fragility and vulnerability

The robustness of three ten-storey RC buildings (basement+ground floor+9 storeys) composed of different structural systems, assessed by their fragility and vulnerability, was analysed. Structures were designed in accordance with the provisions of the set of Eurocodes as ductility class medium (DCM) structural systems. Nonlinear dynamic analysis (NDA) was used for the analysis of the robustness of the structure. The structural response for multiple scenarios of the sudden loss of one vertical bearing element at the ground floor of the building (column or part of walls) was analysed. The results of vertical displacements and structural response at the location of the removed elements were obtained using NDA, which was conducted according to the recommendations of DoD UFC guidelines and GSA. The obtained values were compared, and the differences in the responses of three different building models were determined. The limit states of damage to the structures exposed to progressive collapse were determined and compared. Using the methods of mathematical statistics and probability, fragility and vulnerability curves were constructed, and based on the results, the responses of the structures were analysed. The influence of the position of the removed elements in relation to the centre of stiffness on the robustness of the analysed structural models was analysed. Based on the comparative analysis, the differences, advantages, and deficiencies of the corresponding structural building systems were determined.