Framework for damage-based probabilistic seismic performance evaluation of reinforced concrete frames

The need to consider only a small number of ground motions combined with the complexities of response sensitivity to both modeling choices and ground motion variability has led to the development of new methods to assess structural performance to seismic loads. This research presents a conceptual framework for the probabilistic performance-based seismic assessment of building structures that enables the consideration of model uncertainty and the sensitivity of response and performance measures to ground motion modification.;Finally, the study examines the validity of two ground motion modification schemes: magnitude scaling and spectrum matching. Findings from the investigation indicate that spectrum matching is a more reliable method than scaling and provides the most consistent estimates of median structural performance. The amplitude scaling of records to the first-mode period is sensitive to the choice of records hence a careful selection process is needed to ensure that the computed seismic demands are reliable and consistent.;A careful examination of the response data indicates that the normalized residuals of structural damage are higher at larger spectral accelerations. This suggests that a bilinear or multi-linear representation of the response data may yield a better predictor of the seismic performance for the case studies considered in this study. Future research should explore advanced regression models and new ground motion parameters that better quantify the expected seismic performance of a building to the design event.;Recognizing the need to improve material models so that the modeling uncertainty is minimized, a new constitutive model for reinforcing steel is developed that incorporates degrading behavior, low-cycle fatigue and compression buckling. The model is shown to reproduce with reasonable accuracy observed experimental response of reinforcing bars under monotonic and cyclic strain histories. A new damage model is proposed for the assessment of building performance to seismic loads. The model is derived at the material level and combined at the element, story and structural level through the use of weighting factors.