Local site effects estimation at Amatrice (Central Italy) through seismological methods
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Local site effects estimation at Amatrice (Central Italy) through seismological methods G. Milana1 · G. Cultrera1 · P. Bordoni1 · A. Bucci3 · F. Cara1 · R. Cogliano4 · G. Di Giulio2 · D. Di Naccio2 · D. Famiani1 · A. Fodarella4 · A. Mercuri1 · M. Pischiutta1 · S. Pucillo4 · G. Riccio4 · M. Vassallo2 Received: 30 August 2018 / Accepted: 16 February 2019 © Springer Nature B.V. 2019
Abstract We present the results of seismological and geophysical investigations performed by the “Istituto Nazionale di Geofisica e Vulcanologia” team operating in Amatrice village (Central Italy), in the emergency phases following the Mw 6.0 event of August 24th 2016, that caused severe damage in downtown and surrounding areas. Data from seven seismic stations equipped with both weak and strong motion sensors are analyzed in terms of standard spectral ratio to empirically define amplification function using a bedrock reference site. Ambient vibration spectral ratios between horizontal and vertical component of motion are also evaluated in a large number of sites, spread out in the investigated area, to recover the resonance frequency of the soft soil outcropping layers and to generalize the results obtained by earthquake data. Ambient noise vibration are also used for applying a 2D array approach based on surface waves techniques in order to define the near-surface velocity model and to verify its lateral variation. The results allows to better understand the amplification factors in the investigated area, showing spatial variation of site effects despite of the homogeneous shallow geological condition indicated by the microzonation studies available at moment of the described field campaign. The analysis reveals a diffuse amplification effect which reaches its maximum values in downtown area with a resonant frequency of about 2 Hz. The obtained results were used to integrate the microzonation studies and they can be used for urban planning and reconstruction activities. Keywords Amatrice village · Central Italy 2016–2018 seismic sequence · Site effects · Seismic microzonation · Ambient vibration · Surface waves techniques * G. Milana [email protected] 1
Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Via di Vigna Murata 605, 00143 Rome, Italy
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Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Viale Francesco Crispi 43, 67100 L’Aquila, Italy
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Istituto Nazionale di Geofisica e Vulcanologia, Sezione Centro Nazionale Terremoti, Via di Vigna Murata 605, 00143 Rome, Italy
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Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, C.da Ciavolone, 83035 Grottaminarda, AV, Italy
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Vol.:(0123456789)
Bulletin of Earthquake Engineering
1 Introduction The collection of seismological and geophysical data during a seismic sequence is important for investigating local site amplification effects and their possible role in damage distribution. These data can also be a useful support to seismic microzonation (hereinafter SM) procedures according to the guidelines provided, in Italy, by the Civi
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