Proposal for a soil classification based on parameters alternative or complementary to Vs,30   总被引：2，自引：2，他引：0  

L. Luzi  R. Puglia  F. Pacor  M. R. Gallipoli  D. Bindi  M. Mucciarelli 《Bulletin of Earthquake Engineering》2011,9(6):1877-1898

The selection of specific elastic response spectra according to soil categories is the easiest way to account for site effects in engineering projects and general-purpose hazard maps. Most of the international seismic codes make use of the average shear wave velocity of the upper 30 m (Vs_,30) to discriminate soil categories, although some doubts arose about the capability of Vs_,30 to predict actual soil amplification. In this work we propose two soil classifications in which the soil fundamental frequency (f₀) becomes either an alternative or a complement to Vs_,30. The performance of the derived categorizations is achieved through the estimation of the standard deviation associated to ground motion prediction equations of acceleration response spectra, considering recordings extracted from the Italian strong motion data base. The results indicate that there is a significant reduction of the standard deviation when the classification is based on the couple of variables Vs_,30–f₀, although a classification based of the single f₀ also leads to satisfactory results, comparable with those obtained assuming a classification scheme based on Vs_,30.  相似文献   

Identification of accelerometric stations in ITACA with distinctive features in their seismic response     

Dino Bindi  Lucia Luzi  Francesca Pacor  Roberto Paolucci 《Bulletin of Earthquake Engineering》2011,9(6):1921-1939

In this work, we analyze the records of the Italian strong motion database (ITACA, ) with the aim of identifying stations affected by site effects that are not captured by standard seismic classification schemes. In particular, we consider four different site classifications, two of them based on geological/geophysical characteristics and two driven by data. For each classification we develop a ground motion prediction equation using a random effect approach to isolate the between-station and within-station distribution of errors. The site coefficients obtained for the different classes confirm that site amplification effects are significant for both the horizontal and vertical components. The between-station error normalized to the standard deviation of the between-station error distribution is then used to identify stations characterized by large errors, attributable to site effects not accounted for by the classification schemes. The results show that large errors can affect the predictions when the site effects are not uniquely related to the reduction of the seismic impedance in the uppermost layers. For example, amplifications of ground motion over the long period range are observed for stations installed within alluvial closed-shape basins, as consequence of locally generated surface waves. For these stations, classifications based on the horizontal to vertical response spectra ratio are not reliable, since amplifications are also affecting the vertical component. Another interesting feature which emerges from the analysis is the significant de-amplification of short period spectral ordinates that seems to be related to stations typically set in at the foundation level of massive structures. To increase the usefulness of the data set, the most important distinctive features of the strong motion stations are documented in the ITACA database reports containing the instrument information and the available geological-geotechnical data.  相似文献   

Site effects observed in alluvial basins: the case of Norcia (Central Italy)     

D. Bindi  L. Luzi  S. Parolai  D. Di Giacomo  G. Monachesi 《Bulletin of Earthquake Engineering》2011,9(6):1941-1959

In this work, we investigate the site amplification effects observed in the Norcia plain, Central Italy. Data from 30 selected local earthquakes (2 ≤ Ml ≤ 4.1) recorded by a temporary seismic network composed by 15 stations, are analyzed to determine the spatial variability of site effects. Both the Horizontal-to-Vertical spectral ratio and the Standard Spectral Ratio techniques are applied to estimate the site amplification effects. The results show that most of the sites in the valley are affected by strong amplifications (up to a factor of 20) in the frequency range 0.5–5 Hz. The value of the fundamental frequency of resonance is strictly dependent on the location within the basin and on the sediment thickness. Strong amplifications also affect the vertical components. The time-frequency analysis performed on a station located inside the basin shows the presence of a large spectral amplitudes after the S-wave phase, not observed on a station located on the bedrock, suggesting the presence of locally generated wave trains. Then, in agreement with earlier observations for other alluvial basins in Central Italy, 2D–3D effects play an important role in determining the site amplification effects in Norcia.  相似文献   

Towards an improved seismic risk scenario for Bishkek,Kyrgyz Republic     

D. Bindi  M. Mayfield  S. Parolai  S. Tyagunov  U.T. Begaliev  K. Abdrakhmatov  B. Moldobekov  J. Zschau 《Soil Dynamics and Earthquake Engineering》2011

A risk scenario for Bishkek, capital of the Kyrgyz Republic, is evaluated by considering a magnitude 7.5 earthquake occurring over the Issyk-Ata fault. The intensity values predicted through the application of an attenuation relationship and a recently compiled vulnerability composition model are used as inputs for seismic risk assessment, carried out using the Cedim Risk Estimation Tool (CREST) code. Although the results of this study show a reduction by as much as a factor of two with respect to the results of earlier studies, the risk scenario evaluated in this paper confirms the large number of expected injuries and fatalities in Bishkek, as well as the severe level of building damage.  相似文献   

Reflectance variations in heat-treated ilvaite     

P. Bonazzi  L. Bindi  F. Olmi 《Mineralogy and Petrology》2001,72(4):249-257

Summary Ilvaite, a black mixed-valence iron silicate, undergoes oxidation-dehydrogenation reaction when heated in air. Variations in the optical properties were investigated as function of the structural adjustments accompanying the process. Reflectance measurements were carried out in air on crystallographically oriented crystals heated at increasing temperatures (selected wavelengths of 471.1, 548.3, 586.6, and 652.3 nm). As expected on the basis of the strong structural anisotropy, sections parallel to the c axis (i.e. the chain axis) exhibit maximum bireflectance. The most relevant variation induced by heating affects the R_e value which appears to increase as consequence of the shortening of the M1-M1 contact along the c axis. Received June 5, 2000; revised version accepted November 14, 2000  相似文献   

The Bishkek vertical array (BIVA): acquiring strong motion data in Kyrgyzstan and first results     

S. Parolai  D. Bindi  S. Ullah  S. Orunbaev  S. Usupaev  B. Moldobekov  H. Echtler 《Journal of Seismology》2013,17(2):707-719

We present results from a vertical array of accelerometers that was recently installed in Bishkek (Kyrgyzstan) with the long-term aim of recording strong motion data. Taking advantage of recordings of a Mb 4.7 earthquake that occurred 40 km from the array site during the installation phase, we provide results of some preliminary data analysis. First, estimates of the S-wave velocity and Qs structure are deduced by the inversion of the deconvolved wavefield between the sensors in the borehole. Furthermore, the application of the nonstationary ray decomposition Kinoshita (Earth Planets Space 61:1297-1312, 2009) allowed at least three reflectors in the shallow velocity structure below the array to be identified. The complex nature of the wavefield (with up-going, down-going waves, and converted phases) due to the coarse, unconsolidated subsoil structure is highlighted by means of numerical simulations of ground motion.  相似文献   

X-ray single-crystal and Raman study of (Na<Subscript>0.86</Subscript>Mg<Subscript>0.14</Subscript>)(Mg<Subscript>0.57</Subscript>Ti<Subscript>0.43</Subscript>)Si<Subscript>2</Subscript>O<Subscript>6</Subscript>, a new pyroxene synthesized at 7 GPa and 1700 °C     

Ekaterina A. Sirotkina  Andrey V. Bobrov  Anna V. Spivak  Luca Bindi  Dmitry Yu. Pushcharovsky 《Physics and Chemistry of Minerals》2016,43(10):731-738

A new pyroxene with formula (Na_0.86Mg_0.14)(Mg_0.57Ti_0.43)Si₂O₆, synthesized in a high-pressure toroidal ‘anvil-with-hole’ apparatus at P = 7 GPa and T = 1700 °C, was characterized by X-ray single-crystal diffraction and Raman spectroscopy. The compound was found to be monoclinic (R1 = 2.56 %), space group C2/c, with lattice parameters a = 9.687(2), b = 8.814(1), c = 5.290(1) Å, β = 107.853(2)°, V = 430.08(1) ų. The coexistence of Mg and Ti⁴⁺ at the M1 site does not induce strong modifications either to the M1 site or to the adjacent M2 site. The Raman spectrum of synthetic Na–Ti-pyroxene was obtained for the first time and compared with that of Mg₂Si₂O₆ (with very low concentrations of Na and Ti). The structural characterization of the Na–Ti–Mg-pyroxene is important, because the study of its thermodynamic constants provides new constraints on thermobarometry of the upper mantle assemblages.  相似文献   

A regionally adaptable ground-motion model for fourier amplitude spectra of shallow crustal earthquakes in Europe     

Kotha  Sreeram Reddy  Bindi  Dino  Cotton  Fabrice 《Bulletin of Earthquake Engineering》2022,20(2):711-740

Bulletin of Earthquake Engineering - Typical seismic ground-motion models predict the response spectral ordinates (GMM-SA), which are the damped responses of a suite of single-degree-of-freedom...  相似文献   

Correction to: The probabilistic seismic hazard assessment of Germany—version 2016, considering the range of epistemic uncertainties and aleatory variability     

Gottfried Grünthal  Dietrich Stromeyer  Christian Bosse  Fabrice Cotton  Dino Bindi 《Bulletin of Earthquake Engineering》2018,16(10):4397-4398

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A comparison of approximate techniques for non-linear seismic soil response     

Alfredo Corsanego  Giovanni Solari  Dino Stura 《地震工程与结构动力学》1984,12(4):451-466

Some equivalent linearization techniques, applicable to problems dealing with non-linear seismic amplification of layered soils, are systematically treated and critically compared in this paper. The discussion concerns, in particular, the theoretical consistency, the operative modalities, the computational complexity and the numerical reliability of these methods. A comparison is made between the results furnished by some techniques among those examined and the results obtained through a step-by-step integration of the non-linear equations of motion, assuming as a test-problem the one-dimensional amplification of a horizontally stratified soil deposit characterized by the Ramberg-Osgood constitutive model.  相似文献