Study on Mechanical Behavior of Large-Segment Fully Prefabricated Subway Station During Construction Process

In response to issues of long construction cycles, high pollution, and labor shortages in traditional cast-in-situ subway station construction, a refined 3D model of a large-segment prefabricated subway station was established using ABAQUS software, with mechanical behavior throughout the construction process studied based on the Shenzhen Huaxia Station project case. The model considers soil-structure interaction, incorporates a concrete plastic damage constitutive model and a steel elastic-plastic model, accurately simulates key components, including dry joints of mortise-tenon grooves, prestressed reinforcement, and bolted connections, and implements a sev-en-phase construction sequence. Research findings indicate: 1) During component as-sembly, the roof vault settlement remains ≤3.8mm, but backfilling significantly in-creases displacements (roof settlement reaches 45mm, middle slab deflection measures 66.91mm); 2) Longitudinal mortise-tenon joints develop stress concentrations due to stiffness disparities, with mid-column installation slots identified as vulnerable zones exhibiting maximum Von Mises stress of 32MPa; 3) Mid-column eccentricity induces structural asymmetry, causing increased deflection in longer-span middle slabs, corbel contact stress differentials up to 6MPa, and bolt tensile stresses exceeding 1.1GPa; 4) The arched roof effectively transfers loads via three-hinged arch mechanisms, though spandrel horizontal displacement triggers 5cm rebound in diaphragm wall displace-ment. Conclusions confirm overall stability of the prefabricated structure while rec-ommending optimization of member stiffness matching, avoidance of asymmetric de-signs, and localized reinforcement for mortise-tenon edges and mid-column joints. Results provide valuable references for analogous projects.