Variability of Ground Motion Amplitudes Recorded in Bucharest Area during Vrancea Intermediate-Depth Earthquakes

Florin Pavel,Wahyu Caesarendra

doi:10.1155/2021/5189966

Florin Pavel, Wahyu Caesarendra

Open Access

https://doi.org/10.1155/2021/5189966

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Abstract

This study focuses on the assessment of the correlation and variability of ground motion amplitudes recorded in Bucharest area during Vrancea intermediate-depth earthquakes from a database of 119 pairs of horizontal components. Empirical models for the evaluation of the peak ground velocity and displacement from spectral accelerations are proposed in this study. The distribution of the shear wave velocities from 41 boreholes at specific depths appears to follow a normal probability distribution. The analysis performed in this study has also shown that the variability of peak ground velocities and displacements does not appear to be influenced by the earthquake magnitude. In addition, it was observed that the variability in terms of shear wave velocities at specific depths is smaller than the variability of the spectral amplitudes of the recorded ground motions. The empirical site-amplification factors from the Eurocode 8 draft fail to capture the long-period spectral amplifications observed in Bucharest area during large magnitude Vrancea intermediate-depth earthquakes.

Highlights

Florin PavelIs study focuses on the assessment of the correlation and variability of ground motion amplitudes recorded in Bucharest area during Vrancea intermediate-depth earthquakes from a database of 119 pairs of horizontal components
Significant long-period spectral amplifications have been observed in Bucharest, the capital city of Romania, during large magnitude Vrancea intermediate-depth earthquakes occurring in the past 40 years [1, 2]
Evaluation of Ground Motion Amplitudes e normalised acceleration response spectra as a function of the earthquake magnitude are analysed in Figure 2. e occurrence of significant long-period spectral amplifications for earthquakes with magnitudes larger than 7.0 is noteworthy from Figure 2

Summary

Florin Pavel

Is study focuses on the assessment of the correlation and variability of ground motion amplitudes recorded in Bucharest area during Vrancea intermediate-depth earthquakes from a database of 119 pairs of horizontal components. Empirical models for the evaluation of the peak ground velocity and displacement from spectral accelerations are proposed in this study. E analysis performed in this study has shown that the variability of peak ground velocities and displacements does not appear to be influenced by the earthquake magnitude. It was observed that the variability in terms of shear wave velocities at specific depths is smaller than the variability of the spectral amplitudes of the recorded ground motions. E empirical siteamplification factors from the Eurocode 8 draft fail to capture the long-period spectral amplifications observed in Bucharest area during large magnitude Vrancea intermediate-depth earthquakes

Introduction

Moment magnitude Mw Moment magnitude Mw

PGA PGV

Boreholes Sesimic stations

Relative frequency