THE CONTRIBUTION PROVIDED BY GEOLOGY AND GEOTECHNICAL ENGINEERING IN THE RESTORATION OF TERRACES ON AMALFI COAST

The paper deals with the geomorphological, stratigraphic, geotechnical and stability characteristics of the terraced slopes in the Amalfi-Ravello area (23 km2); the main aim is to evaluate the safety factors of the terrace – dry masonry wall system and to identify the main causes which could cause the collapse. Thanks to several on-site inspections aimed at defining the size of the masonry walls and collecting pyroclastic soils supported by the walls, physical-mechanical laboratory tests and numerical stability analyses were carried out. The latter were performed in both static and dynamic conditions, also evaluating the thrust on the artifact attributable to the formation of perched groundwater tables at the back of the wall. This study showed that in the condition of lack of water infiltration from the rainfalls behind the wall, the whole terrace-wall system is stable, on the contrary it fails. For this reason, the need to install drainage systems that remove rainwater and prevent its infiltration has risen. Taking into account the extension of the terraces in the study area (about 163 km) and the abandonment of ancient agronomic practices in many areas that are difficult to reach, it is believed that this intervention can improve, in many cases, the global stability of these anthropized territories, although highly vulnerable.