Land Subsidence Law of Subway Shield Tunnel Construction Under-Crossing Buildings Considering the Coupling Effect of Double-Line Tunneling and Building Structure

［Objective］ Ground deformation caused by double-line tunnels under-crossing building structures in urban soft soil stratum is relatively complex. It is necessary to study the influence of the coupling effect of double-line tunnel and the upper buildings on ground deformation. ［Method］ Relying on the monitoring data of Suzhou Rail Transit Line 11 project, a 3D tunnel numerical model using the small-strain intrinsic model with PLAXIS 3D software is established, and the land subsidence pattern during the double-line tunnel shield construction is studied. Then, the influence of the double-line tunnel and building parameters is discussed. On this basis, the global sensitivity analysis method is used to evaluate the sensitivity of multiple influencing parameters. ［Result & Conclusion］ Land subsidence curves of the double-line tunnels under-crossing buildings show an approximately symmetrical U-shaped distribution, with the maximum settlement position leaning towards the advancing tunnel. Compared with the advancing tunnel, the construction of the following tunnels has less impact on land subsidence. The ground where the building structure is located presents a concave flexural deformation. The building′s deadweight and aspect ratio are positively correlated with land subsidence, while the tunnel depth, spacing, construction step, and building stiffness are negatively correlated with land subsidence.