Tunnel–pile interaction: a review

Abstract

Tunnel–pile interaction is a key concern in geotechnical research due to the significant impact of tunnelling on the stress and deformation of the soil, as well as on surface structures. Tunnel excavation, especially at shallow depths, often causes ground settlement or heave, which affects the stability of existing structures and their pile foundations. Research on tunnel–pile interaction is conducted through analytical, numerical, and experimental methods. In analytical approaches, a two-step procedure is commonly applied: first, the ground displacement without piles is determined, followed by the analysis of the pile response. Experimental methods include physical modeling under 1g and centrifuge conditions, as well as full-scale prototypes. Full-scale models and field measurements provide real data on pile and soil deformation, which are essential for validating numerical and analytical models. Numerical modeling is widely used due to its ability to fully simulate the tunnelling process using a shield machine and the complex tunnel-pile interactions. It provides a balance between cost, accuracy, and flexibility, making it a powerful tool in both research and design. This paper reviews existing research methods and identifies potential research directions to enhance the accuracy of analysis and design of pile foundation structures.