Numerical modelling of circular RC bridge piers reinforced by carbon or stainless steel considering nonuniform geometric-mechanical degradation

An advanced numerical model was developed for simulating seismic responses of nonuniformly corroded circular RC bridge columns reinforced by carbon or stainless steel. The model was validated against recent lateral cyclic tests, where both overall hysteresis responses and localised mechanisms were replicated satisfactorily. The verified model was then used as the baseline of a Latin Hypercube simulation, where physics-based, age-dependent failure drift ratios of 175 bridge columns were evaluated. The outputs underline potential dangers of using as-built drift limit recommendations for seismic assessments of seemingly younger (e.g., aged 10~20 years) RC bridges. The recommended critical drift ratios were then summarised using machine learning models and encapsulated in a distributable Matlab App for quick future references.