Overview of Stability Research on Long-Span Concrete-Filled Steel Tube Arch Bridges

Concrete-Filled Steel Tube (CFST) arch bridges have developed rapidly in long-span bridge construction, with spans continuously increasing and structural systems becoming more diverse. As structures become more slender, stability issues have gradually become a key factor limiting further development. In recent years, researchers at home and abroad have conducted extensive studies on the static stability, dynamic stability, and nonlinear stability during the construction stage of CFST arch bridges, forming a relatively systematic theoretical and analytical framework. Existing studies have revealed the main factors affecting the ultimate load capacity of the structure from geometric nonlinearity, material nonlinearity, and initial imperfections, and have discussed key issues such as rise-to-span ratio, arch shape parameters, and system transition during construction. Overall, research on the in-service stability of CFST arch bridges has become mature, but systematic studies on the evolution of stability during the full construction process under ultra-long spans and the coupling mechanisms of multiple factors are still relatively limited. Further development of theoretical and analytical methods for construction-stage stability is of great significance for promoting the advancement of CFST arch bridges to larger spans.