Tunnelling-induced safety risks from adjacent piles have become increasingly severe with the rapid development of urban underground space. Model tests have become essential for revealing the complex pile-tunnel interaction mechanism. This paper reviews the research progress of model tests on the influence of single-line tunnelling on adjacent piles, focusing on test soil materials, tunnel simulation methodologies, analysis of test results, and research prospects. However, current model test studies are constrained by several critical limitations, including insufficient similarity between soil materials and prototype conditions, and overly idealized simulation of tunnel excavation. This paper identifies a significant research gap: the inability of current volume-loss techniques to capture 3D dynamic factors (e.g., face pressure and grouting timing) and the lack of meso-scale observation at the pile-soil interface. This review provides a systematic synthesis of these methodological challenges and proposes future research prospects to provide a more scientific basis for engineering design and risk control.

Existing studies often analyze tunnels and excavations as isolated projects, but in practice they are often constructed sequentially or simultaneously. This paper investigates their combined effects on adjacent pile foundations in clay using constant-gravity model tests and 3D numerical methods, considering time-dependent clay behavior and small-strain stiffness. Two combined construction sequences of tunnelling and excavation adjacent to an existing pile were investigated: (i) tunnel excavation followed by basement excavation (i.e., test TEP); (ii) basement excavation followed by tunnel excavation (i.e., test ETP). Results show that construction sequence has little effect on surface settlement but significantly influences pile response. Pile top settlement increases considerably when tunnelling occurs near piles. The TEP sequence reduces cumulative pile top settlement by 0.38% of the pile diameter and reduces the maximum cumulative bending moment by approximately 31% compared with the ETP sequence. Additionally, tunnel and excavation construction generate negative excess pore water pressure in the surrounding soil, which dissipates over time. The pressure increases with proximity to the tunnel face or excavation base.