The influence of tunnel deformation patterns on surface settlement: a case study

Tunnelling-induced ground surface settlement (GSS) poses potential risks to buildings and underground utilities in urban areas. Commonly used approaches for GSS assessment, including three-dimensional (3D) numerical simulations and artificial intelligence techniques, are often limited by high computational costs or poor generalizability. To overcome these limitations, this study proposes a simplified and efficient two-dimensional (2D) numerical method for rapid estimation of GSS at different tunnel cross-sections. The approach replaces the detailed 3D step-by-step excavation processes by employing 2D plane strain conditions, while incorporating convergence patterns characterized by the gap parameter ($g$) and volume loss ($V_L$). Several typical tunnel deformation models are numerically analysed to evaluate their influence on the resulting settlement troughs. The results demonstrate that the proposed method can effectively capture key GSS characteristics while improving computational efficiency. In addition, this method enables probabilistic analysis in the absence of comprehensive field data, supporting early design decisions. Future research can further refine this approach by incorporating more advanced soil constitutive models and considering tunnel–soil interaction effects to improve the accuracy of GSS evaluation.