排序方式： 共有6条查询结果，搜索用时 15 毫秒
1
1.
Fiorucci M. Iannucci R. Lenti L. Martino S. Paciello A. Prestininzi A. Rivellino S. 《Natural Hazards》2016,86(2):345-362
A monitoring system is operative in the Peschiera Springs slope (Central Apennines, Italy) to mitigate the landslide risk related to the hosted main drainage plant of Rome aqueducts by providing alert warning. Such a strategy allows to avoid out-of-service episodes so reducing extra-costs of water distribution management. The Peschiera Springs slope is involved in a rock mass creep characterized by an average steady strain rate of 1 mm year−1 and responsible for several landforms including sinkholes, subvertical scarps and trenches. Moreover, an average aquifer discharge of 19 m3 s−1 causes an intense limestone dissolution concentrated in correspondence with release bands and discontinuities that dislodge the jointed rock mass. Since 2008, an accelerometric network has been operating within the slope; about 1300 microseismic local events were recorded up to now, distinguished in failures and collapses. A control index, based on frequency of occurrence and cumulative energy of the recorded microseismic events was defined to provide three levels of alert. In 2013, a temporary nanoseismic Seismic Navigation System (SNS) array was installed inside a tunnel of the drainage plant to integrate the pre-existent seismic monitoring system. This array allowed to record 37 microseismic events, which locations are in good agreement with the evolutionary geological model of the ongoing gravitational slope deformation. In 2014, a permanent nanoseismic SNS array was installed in the plant and allowed to record several sequences of underground collapses including more than 500 events. The nanoseismic monitoring system is allowing to: (1) increase the detection level of the monitoring system; (2) locate hypocentres of the events; and (3) detect precursors of the strongest events.
相似文献2.
Alexander Eleftheriou Carolina Filizzola Nicola Genzano Teodosio Lacava Mariano Lisi Rossana Paciello Nicola Pergola Filippos Vallianatos Valerio Tramutoli 《Pure and Applied Geophysics》2016,173(1):285-303
Real-time integration of multi-parametric observations is expected to accelerate the process toward improved, and operationally more effective, systems for time-Dependent Assessment of Seismic Hazard (t-DASH) and earthquake short-term (from days to weeks) forecast. However, a very preliminary step in this direction is the identification of those parameters (chemical, physical, biological, etc.) whose anomalous variations can be, to some extent, associated with the complex process of preparation for major earthquakes. In this paper one of these parameters (the Earth’s emitted radiation in the Thermal InfraRed spectral region) is considered for its possible correlation with M ≥ 4 earthquakes occurred in Greece in between 2004 and 2013. The Robust Satellite Technique (RST) data analysis approach and Robust Estimator of TIR Anomalies (RETIRA) index were used to preliminarily define, and then to identify, significant sequences of TIR anomalies (SSTAs) in 10 years (2004–2013) of daily TIR images acquired by the Spinning Enhanced Visible and Infrared Imager on board the Meteosat Second Generation satellite. Taking into account the physical models proposed for justifying the existence of a correlation among TIR anomalies and earthquake occurrences, specific validation rules (in line with the ones used by the Collaboratory for the Study of Earthquake Predictability—CSEP—Project) have been defined to drive a retrospective correlation analysis process. The analysis shows that more than 93 % of all identified SSTAs occur in the prefixed space–time window around (M ≥ 4) earthquake's time and location of occurrence with a false positive rate smaller than 7 %. Molchan error diagram analysis shows that such a correlation is far to be achievable by chance notwithstanding the huge amount of missed events due to frequent space/time data gaps produced by the presence of clouds over the scene. Achieved results, and particularly the very low rate of false positives registered on a so long testing period, seems already sufficient (at least) to qualify TIR anomalies (identified by RST approach and RETIRA index) among the parameters to be considered in the framework of a multi-parametric approach to t-DASH. 相似文献
3.
Seismometer arrays have been widely applied to record collapse by controlled explosion in mines and caves. However, most underground failures are natural events, and because they can occur abruptly, underground failures represent a serious geological hazard. An accelerometric array installed on 4 September 2008 has been used to manage the geological risk of the Peschiera Springs drainage plant of Rome??s aqueduct, which is located in the Central Apennines approximately 80?km from Rome, Italy. The plant occupies a karstified carbonatic slope that is extensively involved in gravitational deformations, which are responsible for underground failures such as cracks and collapses. To distinguish among different types of recorded events, an automated procedure was implemented based on the duration, peak of ground acceleration (PGA) and PGA variation in the recordings of the plant??s accelerometric stations. The frequencies of earthquakes and micro-earthquakes due to underground failures are, in general, well correlated. Nevertheless, many underground failure sequences can be directly associated with the continuous deformations that affect the slope. The cumulative Arias intensity trend derived for the underground failures combined with the failure and earthquake frequencies enabled the definition of a control index (CI) that identifies alarming or emergency conditions. The CI can be used as a tool for managing the geological risk associated with the deformational processes that affect the drainage plant. 相似文献
4.
M. Fiorucci R. Iannucci L. Lenti S. Martino A. Paciello A. Prestininzi S. Rivellino 《Natural Hazards》2017,86(2):345-362
A monitoring system is operative in the Peschiera Springs slope (Central Apennines, Italy) to mitigate the landslide risk related to the hosted main drainage plant of Rome aqueducts by providing alert warning. Such a strategy allows to avoid out-of-service episodes so reducing extra-costs of water distribution management. The Peschiera Springs slope is involved in a rock mass creep characterized by an average steady strain rate of 1 mm year?1 and responsible for several landforms including sinkholes, subvertical scarps and trenches. Moreover, an average aquifer discharge of 19 m3 s?1 causes an intense limestone dissolution concentrated in correspondence with release bands and discontinuities that dislodge the jointed rock mass. Since 2008, an accelerometric network has been operating within the slope; about 1300 microseismic local events were recorded up to now, distinguished in failures and collapses. A control index, based on frequency of occurrence and cumulative energy of the recorded microseismic events was defined to provide three levels of alert. In 2013, a temporary nanoseismic Seismic Navigation System (SNS) array was installed inside a tunnel of the drainage plant to integrate the pre-existent seismic monitoring system. This array allowed to record 37 microseismic events, which locations are in good agreement with the evolutionary geological model of the ongoing gravitational slope deformation. In 2014, a permanent nanoseismic SNS array was installed in the plant and allowed to record several sequences of underground collapses including more than 500 events. The nanoseismic monitoring system is allowing to: (1) increase the detection level of the monitoring system; (2) locate hypocentres of the events; and (3) detect precursors of the strongest events. 相似文献
5.
F. Bozzano L. Lenti Salvatore Martino A. Paciello G. Scarascia Mugnozza 《International Journal of Earth Sciences》2011,100(4):861-879
The basin-like setting of stiff bedrock combined with pre-existing landslide masses can contribute to seismic amplifications
in a wide frequency range (0–10 Hz) and induce a self-excitation process responsible for earthquake-triggered landsliding.
Here, the self-excitation process is proposed to justify the far-field seismic trigger of the Cerda landslide (Sicily, Italy)
which was reactivated by the 6th September 2002 Palermo earthquake (M
s = 5.4), about 50 km far from the epicentre. The landslide caused damage to farm houses, roads and aqueducts, close to the
village of Cerda, and involved about 40 × 106 m3 of clay shales; the first ground cracks due to the landslide movement formed about 30 min after the main shock. A stress–strain
dynamic numerical modelling, performed by FDM code FLAC 5.0, supports the notion that the combination of local geological
setting and earthquake frequency content played a fundamental role in the landslide reactivation. Since accelerometric records
of the triggering event are not available, dynamic equivalent inputs have been used for the numerical modelling. These inputs
can be regarded as representative for the local ground shaking, having a PGA value up to 0.2 m/s2, which is the maximum expected in 475 years, according to the Italian seismic hazard maps. A 2D numerical modelling of the
seismic wave propagation in the Cerda landslide area was also performed; it pointed out amplification effects due to both
the structural setting of the stiff bedrock (at about 1 Hz) and the pre-existing landslide mass (in the range 3–6 Hz). The
frequency peaks of the resulting amplification functions (A(f)) fit well the H/V spectral ratios from ambient noise and the H/H spectral ratios to a reference station from earthquake records, obtained by in situ velocimetric measurements. Moreover,
the Fourier spectra of earthquake accelerometric records, whose source and magnitude are consistent with the triggering event,
show a main peak at about 1 Hz. This frequency value well fits the one amplified by the geological setting of the bedrock
in correspondence with the landslide area, which is constituted of marly limestones and characterised by a basin-like geometry. 相似文献
6.
S. Martino A. Minutolo A. Paciello A. Rovelli G. Scarascia Mugnozza V. Verrubbi 《Natural Hazards》2006,39(3):419-449
Results of geological, geomechanical and seismometric investigations aiming at the analysis of the seismic response in a carbonate
ridge of the Nera River valley (Central Apennines – Italy) are discussed. Geological and geomechanical surveys were aimed
at defining the stratigraphic and structural setting of the outcropping formations and the jointing conditions of the rock
mass. Velocimetric records of both ambient noise and small-magnitude earthquakes were analysed in order to identify amplification
conditions. The analysis was carried out in the time domain, through directional energy evaluation, and in the frequency domain,
through H/V spectral ratios and spectral ratios with respect to a reference station. A local amplification factor was estimated
from Housner intensity. The study revealed a significant seismic amplification in a fault zone. This effect was observed in
intensely jointed and mylonitic rock masses, located inside moderately jointed rock masses, and is the result of specific
geometries and significant impedance contrasts. A map of fault zones prone to amplification of ground motion was constructed,
taking into account the jointing conditions of the rock masses and the structural setting of the investigated ridge. The study
relied on an integrated methodological approach, which combined the available data under union and intersection criteria. 相似文献
1