Centrifuge Modeling of Shallow TBM Excavation in Cohesionless Soils

Publication Title
Centrifuge Modeling of Shallow TBM Excavation in Cohesionless Soils

Abstract

Tunnel face stability in sandy soils was investigated using geotechnical centrifuge modelling. A half-section tunnel model was tested under 50g acceleration, with excavation simulated in a controlled manner using a movable piston. Surface settlements and internal displacement fields were measured via Digital Image Correlation (DIC) and Particle Image Velocimetry (PIV). The experimental results demonstrate the significant influence of soil density and cover-to-diameter ratio (C/D = 0.5, 1.0, and 2.0) on failure mechanisms. In loose sands, broad collapse chimneys extended to the ground surface, whereas dense sands exhibited localized wedge-type failures governed by soil arching effects. Empirical correlations between surface settlement and required face support pressure were established, providing practical guidance for the design and operation of Earth Pressure Balance (EPB) shield tunneling. These findings contribute to improved design criteria for shallow tunnel construction in granular soils, promoting face stability and minimizing surface deformations.

Authors
Aldo Durand; Fernando Saboya; Sergio Tibana; C. Cabral

Published In

11th International Conference on Physical Modelling in Geotechnics (ICPMG2026)

Theme

Session 3: Resilient geotechnical infrastructure