caa a22 4500 445846895 CHVBK 20180317145401.0 cr unu---uuuuu 170323e20110601xx s 000 0 eng 10.1007/s10518-011-9247-5 doi (NATIONALLICENCE)springer-10.1007/s10518-011-9247-5 Seismic response of L'Aquila downtown from comparison between 2D synthetics spectral ratios of SH, P-SV and Rayleigh waves and observations of the 2009 earthquake sequence [Elektronische Daten] [Paola Bordoni, John Haines, Giuliano Milana, Sandro Marcucci, Fabrizio Cara, Giuseppe Di Giulio] This is the first part of a study on the seismic response of the L'Aquila city using 2D simulation and experimental data. We have studied two velocity-depth models with the aim of outlining the behavior of a velocity reversal in the top layer, which is associated with the stiff Brecce de L'Aquila unit (BrA). In this setting, the SMTH model is topped by a layer with about 2:1 impedance contrast with the underlying layer while the NORV model has no velocity reversal. We have simulated the propagation of SH and P-SV wavefields in the range 0-10Hz for incidence 0°-90°. Earthquake spectral ratios of the horizontal and vertical components at six sites in L'Aquila downtown are compared to corresponding synthetics spectral ratios. The vertical component of P-SV synthetics enables us to investigate a remarkable amplification effect seen in the vertical component of the recorded strong motion. Sites AQ04 and AQ05 are best matched by synthetics from the NORV model while FAQ5 and AQ06 have a better match with synthetics spectral ratios from the SMTH model. All simulations show this behavior systematically, with horizontal and near-horizontal incident waves predicting the overall pattern of matches more clearly than vertical and near-vertical incidence. The model inferences are in agreement with new geological data reporting lateral passages in the top layer from the stiff BrA to softer sediments. Matches are good in terms of frequency of the first amplification peak and of spectral amplitude: the horizontal components have spectral ratio peaks predominantly at 0.5Hz in the simulations and at 0.7Hz in the data, both with amplitudes of 4, while the vertical component spectral ratios reach values of 6at frequencies of about 1Hz in both data and simulations. The vertical component spectral ratios are very well matched using Rayleigh waves with incidence at 90°. The NORV model without the velocity reversal predicts spectral ratio peaks for the horizontal components at frequencies up to 6Hz. The reversal of velocity acts as a low-pass frequency filter on the horizontal components reducing the amplification effect of the sediment filled valley. Springer Science+Business Media B.V., 2011 Site response nationallicence 2D synthetic seismograms nationallicence SH nationallicence P-SV nationallicence Rayleigh waves nationallicence Horizontal and vertical component amplification nationallicence Velocity reversal nationallicence Spectral ratios nationallicence Comparison with data nationallicence L'Aquila nationallicence Bordoni Paola Centro Nazionale Terremoti, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143, Rome, Italy aut Haines John GNS Science, Dunedin, 764 Cumberland Street, 9016, Dunedin, New Zealand aut Milana Giuliano Roma1, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna, Murata 605, 00143, Rome, Italy aut Marcucci Sandro Dipartimento Protezione Civile, Ufficio Valutazione Prevenzione e Mitigazione del Rischio Sismico, Via Vitorchiano 2, 00189, Rome, Italy aut Cara Fabrizio Roma1, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna, Murata 605, 00143, Rome, Italy aut Di Giulio Giuseppe Roma1, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna, Murata 605, 00143, Rome, Italy aut Bulletin of Earthquake Engineering Springer Netherlands 9/3(2011-06-01), 761-781 1570-761X 9:3<761 2011 9 10518 https://doi.org/10.1007/s10518-011-9247-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10518-011-9247-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Bordoni Paola Centro Nazionale Terremoti, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, 00143, Rome, Italy aut NATIONALLICENCE 700 1- Haines John GNS Science, Dunedin, 764 Cumberland Street, 9016, Dunedin, New Zealand aut NATIONALLICENCE 700 1- Milana Giuliano Roma1, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna, Murata 605, 00143, Rome, Italy aut NATIONALLICENCE 700 1- Marcucci Sandro Dipartimento Protezione Civile, Ufficio Valutazione Prevenzione e Mitigazione del Rischio Sismico, Via Vitorchiano 2, 00189, Rome, Italy aut NATIONALLICENCE 700 1- Cara Fabrizio Roma1, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna, Murata 605, 00143, Rome, Italy aut NATIONALLICENCE 700 1- Di Giulio Giuseppe Roma1, Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna, Murata 605, 00143, Rome, Italy aut NATIONALLICENCE 773 0- Bulletin of Earthquake Engineering Springer Netherlands 9/3(2011-06-01), 761-781 1570-761X 9:3<761 2011 9 10518 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer