Adding streamlined arc-shaped steel plates to the outer side of a steel box girder can improve rust resistance and aesthetics. A study on a city viaduct with arc-shaped webs analyzed the shear lag effect of the top plate in a wide-span steel box girder. Using a finite element analysis model, researchers found that the shear lag coefficients varied along the length and width of the girder. After adding a steel fiber concrete deck, the distribution of shear lag coefficients changed.