Investigation of the Influence of Ground Models on the Design of Segmental Tunnels Constructed Using TBM Technology: A Case Study on Metro Line 3, Nhon – Hanoi Station

Abstract

This article presents the calculation method and results of internal force survey of segmental tunnel lining structures constructed using Tunneling Boring Machine (TBM) technology. The problem is solved according to the full interaction model between the structure and surrounding soil, accepting the Jassen model in describing the connection between the segments. The selected calculation method is the finite element method with Plaxis 2D software. The analysis results indicate that the Mohr–Coulomb (MC) model produces significantly higher internal force values compared to the Hardening Soil (HS) model across all investigated cases. This discrepancy is particularly pronounced in terms of bending moments and shear forces, whereas the difference in axial forces is relatively smaller and more stable.
Furthermore, the study reveals that the maximum internal forces typically occur during the construction phase of the grout backfilling, when the grouting pressure is directly applied to the tunnel lining. Once the construction process is completed and the system transitions into the operational phase, the internal forces decrease considerably, reflecting the redistribution of stresses and the gradual stabilization of the structural system under long-term working conditions.