 |
| Titel |
Rockfall-induced impact force causing a debris flow on a volcanoclastic soil slope: a case study in southern Italy |
| VerfasserIn |
P. Budetta |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1561-8633
|
| Digitales Dokument |
URL |
| Erschienen |
In: Natural Hazards and Earth System Science ; 10, no. 9 ; Nr. 10, no. 9 (2010-09-27), S.1995-2006 |
| Datensatznummer |
250008411
|
| Publikation (Nr.) |
 copernicus.org/nhess-10-1995-2010.pdf |
|
|
|
|
|
| Zusammenfassung |
| On 10 January 2003, a rockfall of approximately 10 m3 affected a
cliff some 25 m high located along the northern slopes of Mt. St. Angelo
(Nocera Inferiore, province of Salerno) in the southern Italian region of
Campania. The impact of boulders on the lower sector of the slope, along
which detrital-pyroclastic soils outcrop, triggered a small channelled
debris flow of about 500 m3. Fortunately, no damage nor victims
resulted from the landslide. Several marks of the impacts were observed at
the cliff toe and outside the collapsed area, and the volumes of some fallen
boulders were subsequently measured. By means of in-situ surveys, it was
possible to reconstruct the cliff's geo-structural layout in detail. A
rockfall back-analysis was subsequently performed along seven critical
profiles of the entire slope (surface area of about 4000 m2). The
results of this numerical modelling using the lumped-mass method were then
used to map the kinetic iso-energy curves. In the triggering area of the
debris flow, for a falling boulder of 1 m3, the mean kinetic
energy was estimated at 120 kJ, this value being equivalent to an impact
force, on an inclined surface, of some 800 kN. After landing, due to the
locally high slope gradient (about 45°), and low angle of trajectory at
impact (about 23°), some boulders slid down the slope as far as the
endpoints. The maximum depth of penetration into the ground by a sliding
block was estimated at about 16 cm. Very likely, owing to the high impact
force of boulders on the saturated soil slope outcropping at the cliff base,
the debris flow was triggered under undrained loading conditions. Initial
failure was characterized by a translational slide involving a limited,
almost elliptical area where the pyroclastic cover shows greater thickness
in comparison with the surrounding areas. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|