Study of Fatigue Tests on the Structural Details of Welding Joints of Integral Bridge Deck and Main Girder Gusset Plates

Abstract

Under the action of both dead and live loads, the welding joints of the integral bridge deck and the main truss gusset plates of a steel truss bridge in the transverse and longitudinal directions are all subjected to tensile force, the fatigue performance of which greatly influence the safety and durability of the bridge during operation. Fatigue tests were carried out on a full-scale model designed and made in accordance with the structural details of the welding joints of the integral bridge deck and the main truss gusset plates of Dashengguan Changjiang River Bridge. On the basis of the results of the fatigue tests, the stress distribution of the welding joints was analyzed, the fatigue life of the welding joints under load cycles with constant amplitude was discussed and the fatigue performance of the welding joints under the condition of two-way tensile forces was studied. It is concluded that under the effect of fatigue loading with given amplitude, the fatigue life of the welding joints is more than 200 million numbers of load cycles, the structural details of welding joints have ample fatigue resistant ability under the condition of two-way tensile forces, and the maximum main stress value of the fatigue tests is lower than the allowable fatigue stress value given in various codes and relevant references and the fatigue strength meets requirement.