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| Titel |
A strategy to address the task of seismic micro-zoning in landslide-prone areas |
| VerfasserIn |
G. Vessia, M. Parise, G. Tromba |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7340
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| Digitales Dokument |
URL |
| Erschienen |
In: 8th EGU Alexander von Humboldt Conference "Natural Disasters, Global Change, and the Preservation of World Heritage Sites" ; Nr. 35 (2013-06-26), S.23-35 |
| Datensatznummer |
250019094
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| Publikation (Nr.) |
 copernicus.org/adgeo-35-23-2013.pdf |
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| Zusammenfassung |
| As concerns landslide prevention and mitigation policies at the urban scale,
the ability of Geographical Information Systems (GIS) to combine
multi-layered information with high precision enables technicians and
researchers to devote efforts in managing multiple hazards, such as
seismically induced instability in urbanized areas. As a matter of fact,
many villages in the Italian Apennines, placed near high-energy seismic
sources, are characterized by active sliding that are seasonally remobilized
by rainfall. GIS tools can be useful whether accurate Digital Elevation
Models (DEM) are available and detailed mechanical and hydraulic
characterization of superficial deposits over significant portion of the
urban territory is undertaken. Moreover, the classic methods for estimating
the seismic-induced permanent displacements within natural slopes are drawn
from the generalization of Newmark's method. Such method can be applied to
planar sliding mechanism that can be considered still valid wherever shallow
landslides are generated by an earthquake. The failure mechanism depends on
the mechanical properties of the superficial deposits. In this paper, the
town of Castelfranci (Campania, southern Italy) has been studied. This small
town, hosting two thousand inhabitants, suffers from the seasonal
reactivation of landslides in clayey soil deposits due to rainfall.
Furthermore, the site is seismically classified by means of the peak ground
acceleration (PGA) equal to 0.246 g with respect to a 475 yr return period.
Several studies on the evolution of slopes have been undertaken at
Castelfranci and maps have been drawn at the urban scale not taking into any
account the seismic hazard. This paper shows possible seismically induced
hazard scenarios within the Castelfranci municipal territory aimed at
microzonation of level 2, by estimating the slope permanent displacements
comparable to those caused by the strongest historical seismic event that
hit this area: the 1980 Irpinia earthquake. To this aim, geotechnical
characterization of local soils collected over the last 25 yr by local
technicians have been used to predict possible permanent displacements by
means of Newmark's sliding block approach. Two simplified relationships
relating peak ground acceleration and Arias intensity to permanent
displacements have been used and compared. Although similar results are
drawn, the two analyses point out the most hazardous sectors of the
Castelfranci urban area. |
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