Design response spectrum based on shock-waveform decomposition method

Abstract

This study applies the shock-waveform (SW) decomposition method, originally developed for mechanical shock analysis, to earthquake ground motions. It reveals a general shape similarity between the envelope of the Pseudo-Spectral Accelerations (PSAs) of SW decomposed components and the PSA of the corresponding ground motion. Based on this similarity, a novel method to determine the characteristic period $T_g$, the long-period transition period $T_D$, the shape correction period $T_{\beta }$, and the Design Response Spectrum (DRS) is proposed and evaluated. New methods to determine $T_g$, $T_D$ and $T_{\beta }$ from the signal decomposition perspective are integrated into the normalized DRS in Eurocode 8–2022, enabling the construction of the normalized DRS based on SW method (SWDRS). Furthermore, simple ground motion attenuation regression equations are derived to relate the parameters ($T_g$, $T_D$, $T_{\beta }$) and the corresponding spectral ordinates of the normalized SWDRS model with seismic magnitude and site conditions. The SWDRS model is validated by randomly selecting two sites in United States. For each site, the SWDRS is determined by using the attenuation regression equations and the DRS spectral plateau value from the official seismic hazard map. Comparisons between the SWDRS, the latest local DRS, and the severest historical PSA recorded at the specific site demonstrate that the SWDRS provides more accurate spectral values over intermediate- and long-period ranges for structural seismic design.