Fling-Step Recovering from Near-Source Waveforms Database

• Main Authors: Erika Schiappapietra, Chiara Felicetta, Maria D’Amico
• Format: Article
• Language: English
• Published: MDPI AG 2021-02-01
• Series: Geosciences
• Subjects: strong-motion; near-source; earthquake waveforms; permanent displacement; fling-step; waveforms processing
• Online Access: https://www.mdpi.com/2076-3263/11/2/67

We present an upgraded processing scheme (eBASCO, extended BASeline COrrection) to remove the baseline of strong-motion records by means of a piece-wise linear detrending of the velocity time history. Differently from standard processing schemes, eBASCO does not apply any filtering to remove the low-frequency content of the signal. This approach preserves both the long-period near-source ground-motion, featured by one-side pulse in the velocity trace, and the offset at the end of the displacement trace (fling-step). The software is suitable for a rapid identification of fling-containing waveforms within large strong-motion datasets. The ground displacement of about 600 three-component near-source waveforms has been recovered with the aim of (1) extensively testing the eBASCO capability to capture the long-period content of near-source records, and (2) compiling a qualified strong-motion flat-file useful to calibrate attenuation models for peak ground displacement (PGD), 5% damped displacement response spectra (DS), and permanent displacement amplitude (PD). The results provide a more accurate estimate of ground motions that can be adopted for different engineering purposes, such as performance-based seismic design of structures.