STABILITY ASSESSMENT OF TERRACED SLOPES: FIELD DATA AND NUMERICAL MODELLING

This work is finalized to the assessment of the stability of terraced slopes. The study therefore includes the understanding of the failure mechanisms of these particular slopes and the quantification of the influence of hydrogeological and mechanical parameters of dry stone walls and backfill soils both at a large and at a detailed scale. The study was performed in Valtellina. In particular, the slope chosen as study area is the one uphill of the small village of Tresenda, that in 1983 and 2002 was affected by soil slip/debris flow events that caused victims (only in 1983) and severe damages. The topic is of particular interest because it is demonstrated that, during the periods of intense rainfalls that interested Valtellina in the last 30 years, the areas worst hit by superficial landslide events were those terraced by means of dry-stone walls. Various reasonable hypothesis were suggested by various authors about the triggering mechanisms of these events and their principal causes, but nobody has developed a complete, detailed analysis that takes into account both soil and dry-stone walls hydrogeological and resistance characteristics. The present work wants to plug this gap.