Joints representation strategy: Performance evaluation by a Finite Element code. A feasibility analysis of a tunnel infrastructure in the Carnian Alps

This study is part of a wider feasibility analysis of a new forestry road in the Dolomitic region. The investigated area is located in northeastern Italy, in the Carnic Alps complex geological context. The rock mass which would be crossed by the tunnel is a highly tectonized limestone characterized by a relatively high strength of the intact rock. The project focuses on the rock mass characterization and the modelling of its behavior by means of numerical simulations with a Finite Elements (FE) code. The generalized Hoek-Brown criterion is used, normal and shear stiffness of the joints are evaluated and different strategies for the representation of the rock mass discontinuities are adopted. The effects of two support systems, preliminary designed by a diffused simplified method, are evaluated focusing on the space around the tunnel, where the joints reach the critical state.