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11.
Domenico Pileggi David Rossi Enrico Lunedei Dario Albarello 《Bulletin of Earthquake Engineering》2011,9(6):1839-1854
The problem of seismic characterization of rock-mass or stiff-soil outcrops by the use of passive seismic prospecting techniques
is discussed. Difficulties in the application of this kind of procedure in the presence of rugged morphology, high surface
wave velocities and low ambient vibration powers, typical of stiff-soil/rock-mass sites are examined. A methodology to face
these problems is here proposed, which is based on the strict synergy of detailed geologic surveys and application of robust
seismic prospecting techniques, jointly considering single-station and multi-station tools. The application of this approach
for the characterization of a number of sites belonging to the Italian Accelerometric Network is described, focusing on two
representative case histories. 相似文献
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F. G. Piccinelli M. Mucciarelli P. Federici D. Albarello 《Pure and Applied Geophysics》1995,145(1):97-108
The Ridracoli Dam has been operating since 1981. Around the reservoir ISMES installed and operated for 10 years a seismic network, now reduced to a 3-D station. Earthquakes were recorded with completeness from magnitude 0.8 onwards. In the same period, all the parameters relevant to the dam and the environment were measured. This provided a complete data base for RIS studies, unique in its kind in Italy. The main findings of the analyses performed are the following:
- The filling of the reservoir has not influenced the seismicity of the area for most significant events (M L>3.5).
- Lesser seismicity around the reservoir seems to be correlated with water level in the reservoir, but also shows to be dependent on regional seismicity.
- b value shows a slight increase with time. This may indicate an increase in rock fracturing, which is known to precede the disappearing of Type II RIS.
14.
Sebastiano Foti Stefano Parolai Dario Albarello Matteo Picozzi 《Surveys in Geophysics》2011,32(6):777-825
Surface-wave dispersion analysis is widely used in geophysics to infer a shear wave velocity model of the subsoil for a wide
variety of applications. A shear-wave velocity model is obtained from the solution of an inverse problem based on the surface
wave dispersive propagation in vertically heterogeneous media. The analysis can be based either on active source measurements
or on seismic noise recordings. This paper discusses the most typical choices for collection and interpretation of experimental
data, providing a state of the art on the different steps involved in surface wave surveys. In particular, the different strategies
for processing experimental data and to solve the inverse problem are presented, along with their advantages and disadvantages.
Also, some issues related to the characteristics of passive surface wave data and their use in H/V spectral ratio technique
are discussed as additional information to be used independently or in conjunction with dispersion analysis. Finally, some
recommendations for the use of surface wave methods are presented, while also outlining future trends in the research of this
topic. 相似文献
15.
Rodolfo Puglia Dario Albarello Antonella Gorini Lucia Luzi Sandro Marcucci Francesca Pacor 《Bulletin of Earthquake Engineering》2011,9(6):1821-1838
This paper describes the analyses of the single-station ambient-vibration measurements performed on the Italian accelerometric
network to detect site resonance phenomena potentially affecting earthquake recordings. The use of low cost, high quality
microtremor measurement can be helpful to discriminate among soil classes, since several classification schemes based on resonance
frequencies were proposed in the last decades. Operatively, in the framework of the Italian Strong Motion Database project
(DPC-INGV 2007–2009 S4; ), soil resonance frequencies have been evaluated from more than 200 ambient vibration measurements in correspondence of accelerometric
stations included in ITACA (). The noise recordings have been analyzed using the same numerical protocol in order to standardize the results. Particular
attention has been paid to evaluate the quality of measurements and to develop an on-purpose mathematical tool to automatically
estimate the peaks in the horizontal-to-vertical spectral ratio (HVSR) curve. The reliability of the resonance frequencies
from HVSR has been tested by comparing estimates provided by independent methods (modeling or earthquake recordings). The
test confirmed the reliability of the microtremor HVSR for assessing the resonance frequencies of the examined sites. 相似文献
16.
E. Mantovani M. Viti D. Babbucci D. Albarello N. Cenni A. Vannucchi 《Journal of Seismology》2010,14(1):53-65
We argue that the study of long-range interaction between seismic sources in the peri-Adriatic regions may significantly contribute
to estimating seismic hazard in Italy. This hypothesis is supported by the reconstruction of the geodynamic and tectonic settings
in the Central Mediterranean region, the space–time distribution of major past earthquakes, and the quantification of post-seismic
relaxation. The most significant evidence of long-distance interaction is recognized for the Southern Apennines, whose major
earthquakes have almost regularly followed within a few years the largest events in the Montenegro-Albania zone since 1850.
Statistical analyses of the post-1850 earthquake catalogues give a probability of about 10% that a major event in the Southern
Apennines is not preceded by the occurrence of a strong event in the Southern Dinarides–Albanides within 3–5 years. Conversely,
the probability of false alarms is relevant (50% within 3 years, 33% within 5 years). Northward, the tectonic setting and
some patterns of regularity seen in major events suggest that the seismic activation of the main transtensional decoupling
shear zones in the Central Apennines should influence the probability of major earthquakes in the Northern Apennines. 相似文献
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D. Albarello M. Francescone E. Lunedei E. Paolucci M. P. Papasidero G. Peruzzi P. Pieruccini 《Natural Hazards》2017,86(2):401-416
We present a field procedure that has been extensively used in Italy to characterize local seismic response at accelerometric sites and to retrieve ground motion at reference soil conditions by deconvolution analysis. To allow a generalized application to large areas where borehole data are generally lacking or inadequate for the seismic characterization for soils down to the reference seismic bedrock, cost-effectiveness of the considered procedures is a main issue. Thus, major efforts have been devoted to optimize available information and exploit fast and cheap surface geophysical prospecting. In particular, geological/geomorphological survey and passive seismic prospecting (both in single- and multi-station configurations) were jointly considered to reconstruct seismo-stratigraphical site conditions. This information was then used to feed numerical modeling aiming at computing the local seismic response and performing a deconvolution analysis to reconstruct ground motion at reference soil conditions. Major attention was devoted to evaluate and manage uncertainty involved in the procedure and to quantify its effect on final outcomes. An application of this procedure to a set of sites included in the Italian Accelerometric Network is presented. 相似文献
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E. Mantovani N. Cenni D. Albarello M. Viti D. Babbucci C. Tamburelli F. D'Onza 《Journal of Geodynamics》2001,31(5):190
The highly heterogeneous strain field indicated by neotectonic and seismological data in the central-eastern Mediterranean region has been reproduced, at a first approximation, by finite element modelling, of a 2D elastic thin plate. The zone considered is modelled as a mosaic of poorly deformable zones decoupled by highly deformable belts, simulating the major tectonic structures indicated by geological and geophysical evidence. The deformation of the model is obtained by imposing kinematic boundary conditions, representative of the motion of Africa and eastern Anatolia relative to Eurasia. Experiments carried out with different boundary conditions and model parameterisations have provided information on the sensitivity of the model and some insights into the geodynamic behavior of the study area. The deformation pattern of the central Mediterranean area is strongly conditioned by the mechanical properties assumed in the border zones between the Aegean and Adriatic systems. The match of the complex strain pattern observed in the western Anatolian–Aegean–Balkan zones is significantly favoured if high rigidity is assigned to the inner part of this structural system. A motion of Africa with respect to Eurasia compatible with an Eulerian pole located offshore Portugal best accounts for the observed strains in the central Mediterranean region. The match of the strongly heterogeneous strain field observed in the study area can hardly be achieved by simplified models not including major tectonic features and lateral heterogeneity of mechanical properties. The kinematic field resulting from the model configuration which best simulates the observed strain field presents some differences with respect to geodetic measurements in the Aegean–Western Anatolian area, where the computed velocities are systematically lower than the geodetic ones. It is suggested that the most plausible explanation of such differences is related to the fact that the present deformation pattern, inferred from geodetic data, may be different from the middle–long term one, inferred from seismological and geological data. 相似文献