Analysis of Mechanized Shield Tunnel Linings with the ADCM

The design of tunnel linings in soft ground presents a complex challenge, requiring a balance between stability, constructability, and cost-efficiency. Analysis methods are required to account for real soil behaviour, the evolving ground load path, or displacement fields — factors heavily influenced by tunnel boring machine (TBM) geometry and confinement pressures. Capturing this process properly is normally acknowledged to require production of 3D soil-structure numerical models with detailed consideration of the TBM advance and components. The Advanced Displacement-Confinement Method (ADCM) is a semi-analytical, non-iterative procedure that explicitly captures the interaction between TBM operations, soil behaviour, and lining response. It consists of two novel mathematical models / algorithms (SHIELD and RINGS) that are integrated to account for TBM confining pressures, shield geometry, and the anisotropic displacement and stress fields around the tunnel. This paper evaluates the method’s application for the segmental tunnel lining design through comparative analysis via two 2D modelling approaches: A simplified elastic analysis and a detailed numerical model. This is done using unfactored and factored inputs from the ADCM for the ground loading or relaxation respectively, avoiding 3D modelling of the TBM tunnelling process and remaining complaint with design codes. A case study back analysis which included direct monitoring of lining demands with TBM operation and settlements is presented. Results show that both analysis approaches achieve sufficient accuracy indicating that routine 3D modelling can be optional for typical cases, while preserving reliable lining design. In addition, the method uniquely facilitates extensive parametric studies and factored design loading via a focused process for ground parameter and TBM confining pressure adjustments, enhancing safety, efficiency and consistency.