RELIABLE COLLAPSE RISK ASSESSMENT THROUGH HYBRID SIMULATION

Collapse risk assessment of structures requires non-linear analytical models calibrated to representative experimental results, which can ideally capture the realistic collapse behaviour of structures. These analytical models, however, are often calibrated to the results from uniaxial quasi-tatic cyclic or monotonic tests with constant axial load, whereas many important factors that influence the response of a collapsing structure are ignored. Hybrid simulation can be used as an\nimproved alternative to realistically apply complex time-varying boundary effects on structural components and as a result leads to more credible estimates of the collapse probability of structures. The primary objective of this paper is to conduct a\ncomparative study to investigate the use of quasi-static (QS) versus hybrid simulation (HS) test results for collapse risk assessment of reinforced concrete (RC) structures. For this purpose, two identical limited-ductile RC columns were tested by the respective experimental methods using a state-of-the-art Multi-Axis Substructure Testing (MAST) system capable of controlling all six-degrees-of-freedom (6-DOF) boundary conditions in mixed load and deformation modes. A comparative\ncollapse risk assessment was then conducted that highlights the significant discrepancies in the estimates of collapse probability if QS test results are used for the calibration of modelling parameters.\n