Three-Dimensional Finite-Element Analysis of a Novel Pile–Anchor Intersecting Retaining System for Deep Excavations Adjacent to Existing Buildings

To address the challenges of deep excavations adjacent to existing buildings—such as restricted anchor installation angles, construction disturbances, and excessive deformations—a novel pile–anchor intersecting retaining system is proposed. This study employs three-dimensional finite-element simulations via ABAQUS to analyze the mechanical behavior and deformation control performance of this new system. Four comparative models (cross-anchor with/without adjacent buildings, single-anchor with/without adjacent buildings) are established to investigate pile displacement, anchor axial force, and ground settlement during staged excavation. The results demonstrate that the proposed system exhibits superior mechanical behavior. It effectively reduces pile displacement and ground settlement, with reductions of up to 31.7% in final settlement compared to a conventional single-anchor system. The system’s design successfully avoids conflicts with adjacent foundations while providing high structural redundancy. In scenarios adjacent to existing buildings, the system performs safely, with maximum displacements well within code-specified limits. This study confirms that the pile–anchor intersecting system is a robust and practical solution for deep excavations in complex urban environments, offering enhanced safety and deformation control for projects near sensitive infrastructure.