Analysis of Structural Deformation Control Schemes and Sensitivity Parameters for Deep Excavation in Urban Core Areas

Controlling deformation is of paramount importance during deep excavation in urban core areas, particularly deep excavation adjacent to high‐rise structures. This study proposes three support schemes; retaining piles + internal bracing (RPIB, Scheme A), double‐row piles (DRP, Scheme B), and pile‐anchor system (PAS, Scheme C) on a deep excavation near a sensitive high‐rise building in core urban areas. Computational modeling and field monitoring data reveal that Scheme A demonstrates optimal performance in controlling deformation both on the support structure and surrounding buildings. Building settlement was effectively limited to 18.41 mm, and the building tilt ratio was controlled within 0.073%, thereby meeting the requirements of design specifications and safety control standards. Furthermore, the horizontal displacement of the support structure conforms to a Gaussian distribution, with its magnitude varying with depth can be predicted using Gaussian Equations (3) and (4). The data analysis indicates that the calculated values of the model for Scheme A are highly consistent with the cumulative values of the measured data in terms of deformation changing trends. By contrast, Scheme B and C exhibited risks of stability failure at excavation depths exceeding 12 m due to insufficient structural system stiffness. Additionally, a sensitivity analysis was conducted on the key parameters of Scheme A, and this analysis quantified the influence trends of various support parameters on building deformation, thus identifying the optimal parameter combination for the implementation of Scheme A in deep excavations within urban core zones. By comparing and analyzing the original support scheme and the optimized support scheme (employing the optimal parameters) of this project, it demonstrated that the optimized support scheme can reduce the settlement and horizontal displacement of the building by 50.2% and 24.3%, respectively. The optimized Scheme A support system has enhanced the overall stiffness of the foundation pit structure, effectively controlling the deformation of the surrounding building structures. The research results provide theoretical and technical references for deep foundation pit support design and the control of structural deformation during construction in urban core areas.