Seismic responses of super high-rise buildings under long-period ground motions

Abstract

Super high-rise buildings usually exhibit low fundamental frequencies and are particularly susceptible to Long Period Ground Motions (LPGMs) characterized by rich components in long-period range. Previous seismic analyses of super high-rise buildings have primarily considered ordinary earthquake actions, overlooking the influence of LPGMs. To address this gap, the seismic responses of super high-rise buildings ranging in height from 400 m to 800 m are investigated when subjected to LPGMs. The effectiveness of earthquake intensity measures, which serve as indices connecting seismic hazards to structural responses, is evaluated in capturing the seismic effects caused by LPGM excitations. Firstly, this study introduces a statistical model for the response spectra of LPGMs. A simulation algorithm utilizing Continuous Wavelet Transformation (CWT) is then employed to generate LPGMs. Subsequently, simplified shear-flexural models are applied to serve as computational models for super high-rise buildings with varying heights. Furthermore, this study calculates, analyzes and compares typical seismic responses, such as lateral displacements and inter-story drifts, of these super high-rise buildings under simulated LPGMs and ordinary earthquake excitations. Additionally, a set of seismological ground motions is utilized to validate the seismic response analysis. The findings of this study reveal that LPGMs lead to significantly larger responses of super high-rise buildings exceeding 400 m in height compared to ordinary earthquakes. Furthermore, this study examines the correlation coefficients between various existing earthquake intensity measures and seismic responses under LPGM excitations. The results indicate a strong relationship between the LPGM induced responses and the spectral acceleration and velocity at the fundamental periods of the structures. The aim of this paper is to explore the seismic response of super high-rise buildings under LPGMs and provide a scientific basis for their seismic analysis and design.