Optimization of box girder bridge widening techniques: Reinforced Rib vs. Strut solutions

Optimizing existing bridge infrastructure is crucial with the increasing demands of urbanization and traffic. This study investigates methods to enhance the structural performance of single-cell box girder bridges by implementing reinforcing ribs and struts. Focusing on the Tan De Bridge in Thai Binh, Vietnam - a cantilever bridge using a single-cell box girder, the research evaluates load-bearing capacity, deflection, and torsional resistance across three cross-sectional designs: the original single box girder, a box girder with transverse stiffening ribs, and a strutted box girder. The study uses ANSYS Mechanical software for three-dimensional modeling and simulation to examine natural vibration frequencies, stress distribution, and deflection under HL93 loading conditions. ANSYS Mechanical's finite element analysis capabilities allow for a detailed assessment of local and global structural behaviors, providing insights into the different cross-sections' dynamic stability and stress responses. Results indicate that reinforcing ribs and struts significantly improve the bridge's structural integrity. Reinforcing ribs offer superior cross-bridge stiffness, while struts provide optimal stress distribution and reduce flange instability. The study highlights the exceptional flexural resistance of the strutted box girder under eccentric loading, underscoring its potential to optimize bridge design for urban infrastructure demands while ensuring robust structural performance. These findings emphasize the effectiveness of these methods in meeting urban infrastructure needs by facilitating the expansion of bridge width while preserving structural stability and performance.