Sensitivity analysis of finished state parameters for long-span steel box girder cable-stayed

• Proposed "control parameter thresholds" for construction tolerance criteria. • Verified nonlinear modeling necessity via modulus comparison. • Identified temperature-sensitive zones for targeted monitoring. • Developed dynamic control using phase dependency. To ensure the main girder alignment, pylon alignment and cable forces of long-span steel box girder cable-stayed bridges within acceptable range after construction, a parametric sensitivity study was conducted on the Xuefu Road Bridge in Shijiazhuang City. A finite element model simulating the entire construction process was established using Midas Civil software. The influence of beam weight, cable tension, girder stiffness, structural temperature and cable sag effect on the bridge alignment and internal forces was investigated. Results show that the beam weight and cable tension have significant impact on the final bridge state and should be strictly controlled during construction, while the girder stiffness and cable sag effect play a less sensitive role. The findings provide useful reference for bridge construction control, error correction, and construction safety improvement.