Challenges in experimental modelling of pile-soil-tunnel interaction using a small diameter centrifuge

Publication Title
Challenges in experimental modelling of pile-soil-tunnel interaction using a small diameter centrifuge

Abstract

Protection of existing (buried) infrastructure is a key requirement when tunnelling in dense urban areas. Structures supported by pile foundations necessitate additional pile stability checks, as tunnelling in their proximity induces ground movements which can lead to increased axial forces, bending moments and displacements which may affect the integrity of the piles. Centrifuge modelling is a widely adopted technique for investigating the impact of tunnelling on adjacent piles. It offers several advantages, including the ability to accurately replicate the stress-strain behaviour of the prototype problem, whilst being cost effective and repeatable. However, careful consideration of test preparation techniques, scaling and instrument selection and accuracy is essential since errors are magnified due to the small values being measured. This paper discusses the challenges associated with using the small, 1.5 m diameter centrifuge in the National Buried Infrastructure Facility (NBIF) at the University of Birmingham to study pile-soil-tunnel interaction. Key hurdles identified and discussed in this study include: (a) inaccuracies introduced by the pluviation technique and assessing the relative density and, (b) the difficulty in controlling the tunnel volume losses of the small model and (c) selection of high precision instrumentation to obtain reliable data given the small package size. Careful pluviation using a movable support was adopted to achieve the relative density of 70%.

Authors
P. Yensri; Andrei Dobrisan; Asaad Faramarzi; N. Metje; Kieran Hansard; Christopher Harbutt; Ethan Ashton

Published In

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

Theme

Session 4: Sustainability in geotechnical systems