Probabilistic seismic response sensitivity of nonlinear frame bending-shear and infill model parameters for an existing infilled reinforced concrete structure

The seismic performance of older infilled frame reinforced concrete structures is influenced by the interaction of different components and mechanisms and is highly sensitive to several modelling parameters. A probabilistic response sensitivity analysis is performed on a case study consisting of an infilled frame structure incorporating state-of the art models of most significant sources of nonlinear behaviour: 1) axial-moment interaction in the frame components, 2) cracking and crushing of infill panels, and 3) infill-frame interaction induced shear failure of columns. Nonlinear fiber section beam column elements are assembled with eccentric ASCE41/FEMA356 infill strut models, hysteretic shear models of captive columns based on EC8 shear strength, and are processed through pushover-based tornado analyses. Probabilistic sensitivity to material parameters at operation, damage, life safety and collapse limit states indicates that modelling parameters of infill and mass source have a key impact on the system response.