For a long period, and still nowadays, gravity mass movements have represented a risk for the village of Acqualoreto, particularly for those buildings and infrastructures lying on the north-western side of the town. This territory (which lies in the municipality of Baschi, Terni, Umbria) is classified as a high risk landslide area (area R3 in the Plan of the Hydro-geological Structure drawn up by the River Tiber Basin Authority). The village had previously been included among the towns to be reinforced by, and at the expense of the State according to the D.P.R. n° 1349 of 24/11/1966 (Royal Decree 445/1908). The area lies on the edges of a narrow, procumbent ridge which coincides with part of the niche of a large paleo-landslide. The large landslide has been classified as a flow which almost completely fills the catchment basins of the two streams (Fosso Petrusi and Fosso della Cupa), tributaries into the left-hand hydrographic area of the River Tiber, along the Forello gorge between the towns of Todi and Orvieto. The paleo-landslide does not show any evidence of possible re-activation, however, but over sixty active or dormant landslides classified as slips or flows have been identified along parts of the surface of the accumulation body and along the scarp which forms the large erosion scar. A series of geo-technical investigations were carried out in the area classified as a high risk landslide area (R3) during the period from October 2002 to July 2003 with the aim of defining not only the geometry and kinematism of the landslides, but also the geomechanical and hydro-geological characteristics of the subsoil. The investigations included n° 8 depth-integration drillings; n° 3 nucleus destruction drillings; n° 3 seismic refraction profiles and n° 9 DPSH dynamic penetration tests. Furthermore, geotechnical monitoring instruments (dip needles and observation pipes) were installed and a series of instrumental measurements were taken and which are still currently in progress. The series of investigations was concentrated upstream from the village of Acqualoreto in order to better define the risks threatening it.
The large Acqualoreto landslide (Terni, Umbria, central Italy): mass movements analysis and risk evaluation
MELELLI, Laura;
2004
Abstract
For a long period, and still nowadays, gravity mass movements have represented a risk for the village of Acqualoreto, particularly for those buildings and infrastructures lying on the north-western side of the town. This territory (which lies in the municipality of Baschi, Terni, Umbria) is classified as a high risk landslide area (area R3 in the Plan of the Hydro-geological Structure drawn up by the River Tiber Basin Authority). The village had previously been included among the towns to be reinforced by, and at the expense of the State according to the D.P.R. n° 1349 of 24/11/1966 (Royal Decree 445/1908). The area lies on the edges of a narrow, procumbent ridge which coincides with part of the niche of a large paleo-landslide. The large landslide has been classified as a flow which almost completely fills the catchment basins of the two streams (Fosso Petrusi and Fosso della Cupa), tributaries into the left-hand hydrographic area of the River Tiber, along the Forello gorge between the towns of Todi and Orvieto. The paleo-landslide does not show any evidence of possible re-activation, however, but over sixty active or dormant landslides classified as slips or flows have been identified along parts of the surface of the accumulation body and along the scarp which forms the large erosion scar. A series of geo-technical investigations were carried out in the area classified as a high risk landslide area (R3) during the period from October 2002 to July 2003 with the aim of defining not only the geometry and kinematism of the landslides, but also the geomechanical and hydro-geological characteristics of the subsoil. The investigations included n° 8 depth-integration drillings; n° 3 nucleus destruction drillings; n° 3 seismic refraction profiles and n° 9 DPSH dynamic penetration tests. Furthermore, geotechnical monitoring instruments (dip needles and observation pipes) were installed and a series of instrumental measurements were taken and which are still currently in progress. The series of investigations was concentrated upstream from the village of Acqualoreto in order to better define the risks threatening it.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
