Modellazione agli elementi discreti di reti metalliche per applicazioni di rinforzo corticale

Secured drapery systems are extensively used to mitigate the risk connected with shallow instabilities and rockfall in both soil and rock slopes. Despite the wide application of these systems, various features of their mechanical behaviour in field conditions remain unknown. This lack of knowledge is related to the fact that the standard laboratory configurations adopted for mesh mechanical characterisation are poorly representative of the field conditions. In this thesis, the Discrete Element Method is used in order to analyse the mechanical behaviour of wire meshes in secured drapery applications. Experimental results, obtained from several test configurations, are used to validate the mesh model. This has permitted to prove the effectiveness of the adopted numerical approach in simulating the mechanical response of a wire mesh from simple laboratory conditions to complex configurations in which the mesh interacts with multiple external bodies. The mesh model is adopted to address the problem of the punching behaviour of an anchored mesh. This represents the most likely condition in secured drapery installation aimed to retain potentially unstable blocks along rock slopes. A parametric study is conducted, leading to the definition of simple analytical relations that can enable practitioners to account for the effect of the problem’s variables on the mechanical response of the mesh system. A simple procedure allowing for the extension of the standard laboratory mechanical characterisation (i.e. standard UNI punch test) to a general field condition is also provided. A large-scale model of a secured drapery system in soil retaining applications is implemented. The obtained results have permitted to characterized the force transmission mechanism inside the mesh system, thus highlighting the role of the different system components. A parametric analysis is performed to investigate the role of several variables on the mechanical response of the mesh system. Particular attention is devoted to the evolution of the unstable process in the retained material. This has permitted to identify a failure mechanism that may be considered as typical in such kind of applications.