Effects of near-fault pulse-like and non-pulse-like seismic excitations on the structural response of steel high-rise buildings with buckling restrained braces

The seismic assessment of high-rise structures, especially in near-fault regions, necessitates advanced design solutions. This study evaluates the seismic performance of a 37-story steel Special Moment-Resisting Frame (SMRF) building equipped with Buckling-Restrained Braces (BRBs), subjected to near-fault pulse-like and non-pulse-like ground motions. The model, designed following ASCE7-22 standards, incorporates BRBs to enhance energy dissipation and mitigate inelastic deformations. Nonlinear time history analysis (NTHA) on the 3D model was conducted using OpenSees, considering key parameters such as inter-story drift ratio (ISDR), normalized base shear, and peak story accelerations. Also, the nonlinear response of the beam, column, and BRB have been presented. The results reveal distinct seismic response patterns based on the ground motion characteristics. Pulse-like records induce significantly higher demands, particularly at upper stories, manifesting in amplified accelerations and inter-story drifts compared to non-pulse-like records. In the most critical case, this resulted in approximately a 40% increase in drift and a 20% increase in acceleration. Conversely, non-pulse-like motions impose prolonged but less intense demands, leading to greater cumulative damage over time. The study underscores the critical need for incorporating both pulse-like and non-pulse-like ground motions in seismic assessments and highlights the importance of balanced stiffness and ductility in BRB-integrated designs. These insights contribute to the improvement of seismic design methodologies, ensuring the resilience and safety of tall buildings in earthquake-prone regions.