Experimental Study on Fatigue Properties of Rib-To-Deck Welds Repaired by Angle Steel

Orthotropic steel deck as an essential component of steel box girder has numerous advantages, such as lightweight and high bearing capacity. However, due to the repeated action of wheel load and congested traffic, the welds of the deck to U-rib are prone to produce cracks. There are four common types of cracks at welds of U-rib-top plate of orthotropic steel deck, one of which is the transverse crack that initiates at the weld root through the weld throat. Considering that the cracks mentioned above have been found in some U-rib-top plate welds of many steel bridges, this study aims to experimentally quantify the fatigue performance of transverse cracks repaired by bonded angle steel. The test specimens included the unreinforced reference group and the strengthened group with bonded angle steel. All groups’ fatigue patterns and fatigue life were obtained under the lateral fatigue loading. Compared to the unreinforced specimens, the average stress amplitude of U-rib’s weld root, which has been reinforced by angle steel, has declined significantly. In addition, the fatigue stress of the U-rib’s weld root reinforced by bonded angle steel was found to be effectively reduced, and the fatigue life of U-rib’s weld root reinforced by angle steel is estimated to be at least 13 times that of unreinforced specimens, according to the S-N curve of European standard.