ANALISI DI STABILITÀ DI MURI A SECCO IN AREE TERRAZZATE

The presence of terraced areas in Italy is known since a long time. Terraced areas are found all over in Italy, from the Alps to the Apennines and in the insular Italy, both in the hilly and mountainous zones, representing distinguishing elements of the cultural identity of the country, in particular of the rural areas. From the 50’s, the progressive abandonment of the agricultural areas, induced the deterioration of the containing walls of the terraces, up to their collapse in some cases. The study of the terraces is nowadays of a great importance, mainly due to their economic, environmental and historical-cultural importance, besides the already well known hydrological functions such as erosion control, slope stabilization, lengthening of the of the concentration time and the eventual reduction of the surface runoff. DEISTAF of the University of Firenze started the mapping and the characterization of the agricultural terraces at regional level, in order to set up a database containing information such as site georeferencing, technical parameters, typology and conservation status of the walls and area land use. The present paper aims at the individuation of the stability level of the single stone wall, through an analysis method able to obtain information on the overturning, translation, load-bearing capacity of foundation soil. The study area, of roughly 1 ha, is located in the commune of Pontremoli (MS), on a slope of 28%, with vineyard land use. The site survey has been carried out after the flood event of October 25, 2011, characterized by a precipitation of more than 400 mm with associated return period of 500 years for that area. The stability conditions have been analyzed under the influence of the geometry of the wall structure, the soil parameters, the presence of wall slope, earthquake and aquifer. The simulated conditions are consistent with those of the flood event (upstream saturation and runoff concentration).