WITHDRAWN Simulation of Region-Specific Ground Motions at Bedrock by Combining Spectral Decomposition and Empirical Green’s Functions Approaches
Description:
WITHDRAWN Estimating earthquake ground motions at reference bedrock is a major challenge in seismic hazard assessment. The majority of recordings available in strong-motion databases are from stations installed on soil or soft-rock sites implying large epistemic uncertainties when assessing ground motion at bedrock using empirical ground motion models (GMMs).
We propose a methodology to simulate region-specific reference-bedrock time histories by combining spectral decompositions of ground motions with Empirical Green’s Functions (EGFs) simulation technique. First, we adopt the nonparametric generalized inversion technique (GIT) to separate the contribution of source, path, and site terms. We remove the average source and site effects from observed small-magnitude recordings in the target region through deconvolution in the Fourier domain. This way, the obtained deconvolved EGFs represent path term only. Then, we couple the EGFs with k-2 kinematic rupture models for target scenario events. For each target magnitude, a set of rupture models following a ω-squared source spectrum are generated sampling the uncertainties in kinematic source parameters. The proposed approach is first validated using recorded ground motions at reference sites from multiple earthquakes in Central Italy. A further application to a low seismicity region is also presented to discuss the advantages and limitations of the method. The power of this approach lies in its ability to map the path-specific effects into the ground-motion field, providing 3-component time histories covering a wide frequency range, without the need for computationally expensive approaches.
The region-specific, site-effect-free dataset produced by this approach can be used alone or in combination with existing empirical datasets to adjust existing GMMs, derive new GMMs, or select hazard-consistent time histories to be used in soil or structural response analysis.
Session: From Earthquake Recordings to Empirical Ground-Motion Modelling [Poster Session]
Type: Poster
Date: 5/2/2024
Presentation Time: 08:00 AM (local time)
Presenting Author: Gabriele
Student Presenter: No
Invited Presentation:
Authors
Gabriele Ameri Presenting Author Corresponding Author gabriele.ameri@seister.fr SEISTER |
Hussein Shible hussein.shible@seister.fr SEISTER |
David Baumont david.baumont@seister.fr SEISTER |
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WITHDRAWN Simulation of Region-Specific Ground Motions at Bedrock by Combining Spectral Decomposition and Empirical Green’s Functions Approaches
Category
From Earthquake Recordings to Empirical Ground-Motion Modelling