Numerical modeling of tunnel excavation interacting with a building

This thesis investigates the effects of tunnel excavation-induced ground movements on buildings through a numerical study of Napoli Metro Line 6. Using PLAXIS 3D finite element modeling, interactions between tunnel settlements and existing structures were analyzed. Both greenfield and soil-structure interaction scenarios were modeled to assess the influence of building stiffness and foundation properties. The Mohr-Coulomb and Hardening Soil models, including HSsmall, simulated nonlinear soil behavior along the tunnel alignment, covering sand, pyroclastic soils, cinerite, and tuff. Model calibration was performed using results from geotechnical investigations. Analyses focused on settlement troughs, horizontal displacements, and internal forces in building elements. Axial forces (ΔN) and vertical displacements (Δuz) were examined under interface stiffness variations (R=1 and R=0.01). Results indicate that building stiffness significantly modifies ground deformation, reducing settlements in sagging zones while maintaining or increasing deformations in hogging zones. The study highlights the importance of soil-structure interaction and advanced numerical modeling to minimize structural risks in urban tunneling projects.