Design Concept and Analysis of Innovative Bridge Girders Using Hollow Tubular Flanges

Compared with traditional multi-girder bridge systems, an I-girder system using two main girders simplifies the construction process and saves material consumption and is becoming a representative system used in bridge industrialization in China. However, owing to the low torsional stiffness and poor stability of the traditional I-section, more lateral connections (diaphragms or cross-frames) and stiffeners are required to form a frame to ensure safety and structural performance during the construction process. This article proposes an innovative girder system with hollow top tubular flanges to replace the top plate of the traditional I-section with a hollow rectangular tube that improves the torsional stiffness of the traditional I-section, but the bending performance is basically unchanged. In this article, the structural performance of this innovative system is studied, and compared with the traditional I-girder system. The analysis results show that the innovative bridge system using tubular flange has better performance than the traditional I-girder system, and can be applied to industrialized bridge construction.