The study looked at how the diaphragms in a steel bridge support behave when the weight on them increases. By analyzing real structures, researchers aimed to make steel bridges more efficient and longer-lasting. They focused on the diaphragms and vertical bracing of the steel box girder support. The study found that stress on the support diaphragms in a steel box girder changes as the load increases. Both tests and analyses were done to understand how a steel box girder bridge behaves during repairs or maintenance.