Identification of the strong velocity pulse considering three-dimensional ground motion

Pulse-like ground motions (PLGMs) exhibit pronounced orientation-dependent characteristics, underscoring the necessity of identifying the strong velocity pulse across all orientations. This study aims to address the limitations of prior studies that identified the pulse by considering only the horizontal components. Utilizing typical seismic records from the NGA-West2 database, the study focuses on the pulse identification in three-dimensional (3D) space. Initially, the study examines the spatial amplitude characteristics of PLGMs, emphasizing the impact of the vertical component on PLGMs. Subsequently, a method for identifying the pulse based on the maximum peak ground velocity (PGV) of three orthogonal orientations is proposed. By comparing the identification results of the proposed method with those obtained by the widely adopted Baker (2014) method, its applicability and accuracy are confirmed. Furthermore, the pulse orientation is assessed by examining the inelastic response of the structure, suggesting its applicability in seismic engineering practice to estimate the maximum seismic demand on structures.