Full-stage simulation and validation of multi-body incremental launching mechanics for complex curve bridges

To address mechanical analysis challenges of multi-body incremental launching for complex curve bridges in urban reconstruction, traditional methods suffer from incomplete working condition coverage, geometric model distortion, and inadequate core component simulation. This study establishes a refined full-stage calculation system: proposes a mathematical expression of the launching process and automatic constraint state judgment method, develops a finite element strategy (rapid 1D linear modeling and accurate 3D spatial mapping), and designs a Python-based automated program for MIDAS MCT command stream generation. Validated by the Guangzhou-Shenzhen Expressway reconstruction project, it covers 771 working conditions, accurately extracts key mechanical responses (support reactions, ductile hinge shear forces, displacements, stresses), and quantifies the influence of linear curvature and torsion. The method mitigates the shortcomings of traditional approaches in terms of computational efficiency, completeness of working condition coverage, and geometric fidelity, establishing an efficient automated analysis process that covers the entire construction stage. It promotes the digital and intelligent evolution of incremental launching mechanical analysis, offering technical support for safe and precise bridge construction in complex environments.