Probabilistic seismic demand modeling of continuous concrete box-girder bridges: emphasizing hysteretic energy and residual demands

Abstract Energy-based seismic design is an innovative approach that systematically incorporates energy-related demands of ground motion to analyze and design structures, particularly in near-field regions. This study investigates the seismic behavior of three multi-span continuous concrete box-girder (MSCC-BG) bridges subjected to 328 ground motions, including pulse-like and non-pulse records, using the OpenSees framework. Twenty-eight energy-related, residual, and displacement-based demands and thirty-six intensity measures (IMs) from horizontal and vertical earthquake components are analyzed. Key correlations between these demands and various IMs are identified, focusing on the most critical demands under pulse-like earthquakes. A multi-variable probabilistic seismic demand model (PSDM) is developed using Lasso and stepwise regression for critical demands, such as column hysteretic energy and residual drift ratio. While the multi-variable PSDM demonstrates improved prediction accuracy compared to single-IM models, the improvement for the examined demands is modest. These findings highlight the importance of incorporating horizontal and vertical ground motion IMs in PSDMs to enhance predictive accuracy and provide a foundation for further refinement in energy-based seismic design methodologies.