Landslide evolution controlled by climatic factors in a seismic area. Prediction methods and warning criteria

Informazioni relative al progetto

ID dell’accordo di sovvenzione: EV5V0451

Progetto chiuso

Data di avvio 1 Luglio 1994

Data di completamento 30 Settembre 1996

Finanziato da

• Specific research and technological development programme (EEC) in the field of the environment, 1990-1994

Costo totale € 0,00

Contributo UE Nessun dato

Coordinato da

Politecnico di Bari
Italy

Exploitable results

Landslide evolution controlled by climatic factors in a seismic area: prediction methods and warning criteria

The research study dealt with the influence of climate, rainfall and runoff on the stability of soil slopes forming part of the orogenic chain of the Southern Apennines (Italy). The study addressed the basic understanding of the mechanics of the slopes in order to derive the role of rainfall and seismic events in these mechanics. The environmental factors were studied as well as the characteristics and behaviour of a number of different slopes. The mechanics of one of these slopes, the Acquara-Vadoncello slope, in the area of the town of Senerchia, was the subject of a multidisciplinary experimental study based on: in-situ complex monitoring (climatic data logging, piezometric and inclinometric measurements, both terrestrial and global positioning system (GPS) topographic survey, aerial photograph interpretation, accelerometric and gravimetric survey, etc), laboratory testing (triaxial, simple shear and ring shear tests) and numerical modelling (geological, piezometric and geotechnical). An initial conclusion of the study was that the morphological environment and the poor mechanical properties of the materials involved make the site predisposed to failure. The steady ground water conditions are critical for the propagation of failure in the soil masses, which is a progressive process evolving at depth. There is not an immediate response to rainfall and seismic events. These are at least an indirect cause since, at the origin of both the complex morphology of the slopes and the weakness of the materials, there is the tectonic history of the area and the landslide events triggered by the frequent seismic shaking. The fact that the slope failures are often delayed with respect to the earthquakes suggests that it is the increase in pore water pressure generated by the seismic event, which is responsible for the instability rather than the seismic loading per se. These conclusions would necessarily apply to any slope with similar soils.