Environmentally Sustainable Solutions for Slope Consolidation in the Deruta Historic Center

A large part of the Italian territory is prone to hydrogeological instability, due to its peculiar geological and geomorphological characteristics. Climate changes and anthropic transformations accentuated these processes, causing situations of ecological and environmental imbalance, and making the necessary interventions for risk mitigation extremely expensive [1]. A possible approach to face this issue, based on an environmentally sustainable criterium, is the use of ground bio-engineering techniques, relying on the use of vegetation. To quantify the improvement in slope stability produced by root reinforcement, the mechanical and hydraulic stabilizing contribution provided by the roots has been investigated separately considering a series of ideal slopes, using the Plaxis 2D code. The slope safety factor has been determined in the case of slopes without vegetation - assumed as reference models - and slopes with vegetation, considering the influence of: i) slope inclination; ii) mechanical characteristics of the soil; iii) contribution of a root system at different depths. From the results of the numerical simulations, it has been possible to observe that: a) in general, the stability of the slope increases in presence of a vegetal cover, with greater benefits for coarse-grained soil; b) the root system improves the behaviour of the slope also in the period of their transient development, and the stability of the slope increases progressively with the deepening of the roots; c) for the soils considered, the mechanical stabilizing effect is greater than the hydraulic one.