Structural performance of deteriorating reinforced concrete columns under multiple earthquake events

Abstract

This study investigates deteriorating reinforced concrete (RC) columns subjected to multiple earthquake events, taking into consideration how a combination of environmental stressors and extreme loads can adversely affect the performance of RC columns during their expected service life. For this purpose, nonlinear finite-element models are developed with all the necessary details, validated with a set of experimental test results, and then employed to predict the extent of structural degradation as a function of age and prior earthquake-induced damage. This is through a systematic approach to capture the consequences of corrosion-induced deterioration, in terms of rebar cross section loss, drop of steel yield and ultimate strength, and degradation of bond. The consequences of earthquake events are evaluated with not only structural damage caused by lateral loads, but also the corrosion process expedited as a result of residual damage. Such a holistic assessment strategy paves the way to obtain realistic predictions for the performance of RC columns under future earthquake events. To study this critical aspect, a set of representative scenarios that consist of two earthquake events of different intensities are defined. Considering that RC columns in service commonly experience more than one earthquake during their lifetime, the outcome of this study contributes to transforming the accuracy of predictions made on the residual capacity and seismic response of structures subjected to multiple stressors and hazards.