Uncertainty and Sensitivity Analysis of Reinforced Concrete Frame Structures Subjected to Column Loss

Abstract

In this study, the variability inherent in the performance of RC frame structures to bridge over a column loss was investigated, considering the uncertainties existing in gravity loads, material properties, and construction geometries. Uncertainty and sensitivity analysis were conducted in tandem to provide the influence and significance of the uncertain parameters on RC frames to resist progressive collapse. Quasi-static pushdown analysis was used to assess the residual load-resisting capacity of structures with an initialized damage. A set of structural models were generated for uncertainty analysis by using the correlation-reduced Latin hypercube sampling method. Sensitivity analysis was performed by independently varying parameters with one standard deviation away from their means. Two typical RC frame structures with different span aspect ratios were taken as the study cases. The macromodeling technique, which was validated by the test results, was used for analysis. The study results indicated that structural uncertainties have significant effects on the behavior of RC frame buildings for mitigating progressive collapse caused by the loss of a ground column. Among the studied uncertain parameters, the gravity loads and the properties of reinforcement have the most effects on the residual load-resisting capacities of damaged frames.