Integrated investigation of an incremental launching method for the construction of long-span bridges

• An integrated approach is conducted to investigate the effectiveness of the incremental launching method for the construction of bridges.
• The stress and deformation levels of the launched structures are focused to verify construction safety for the bridges.
• The temporary connectors between steel arches and longitudinal girders are shown critical to the structures during the launching process.
• The wind load is demonstrated to have a significant effect on stress and deformation of the structures during the critical launching stages.
• Stiffening key components is recommended to ensure the safety of bridge structures during the erection process under severe conditions.

This paper conducts a combined experimental and numerical study of the effectiveness of the incremental launching method for the construction and erection of continuous hybrid arch-girder bridges. To verify construction safety for these bridges, the investigation focuses on the stress and deformation levels of the launched structures during the launching process. The stress fluctuation of structural members is analyzed at critical launching stages under the mechanical and wind loads. It is shown that the temporary connectors between steel arches and longitudinal girders are critical to the structures during the launching process, and that the front connector of the first launched span needs specific attention to avoid fatigue and buckling issues. It is further demonstrated that the wind load has a significant effect on both stress and deformation, especially during the critical launching stages. Stiffening the key components is recommended to ensure the safety of bridge structures during the erection process under severe weather and wind conditions.