Construction method for improving fatigue strength of welding joint of orthotropic steel bridge deck

Abstract

The invention relates to a construction method for improving fatigue strength of a welding joint of an orthotropic steel bridge deck, mainly aiming at welded toes of a welded joint of an orthotropic steel bridge deck unit U-shaped longitudinal rib and a longitudinal angle joint of the bridge deck. The construction key point of the construction method comprises the following steps of: firstly fixing a bridge deck unit on a construction jig at a horizontal position, rotating the construction jig to enable the bridge deck unit and the ground to form an inclined included angle of 15-25 degrees so that the welded joint on one side of the U-shaped longitudinal rib is arranged at a ship-like position, re-melting all welded toes of the welded joint at the ship-like position by full-automatic argon tungsten-arc welding without welding wires through a welding tractor, and re-rotating the construction jig so that the bridge deck unit re-welds the welded toes on the other side at a position of the same included angle by a same process. During construction, an argon tungsten-arc welding gun is clamped on the welding tractor and ensures reasonable angles and distances of the welding gun and the welded toes by regulating clamping states of the welding gun. On the construction jig, the full automatic welding operation has high efficiency and is easy to control, and the quality of the re-molten welding joint is stable and reliable.

Description

technical field [0001] The invention relates to a construction method for improving the fatigue strength of welded joints of orthotropic steel bridge decks, specifically a method for improving the U-shaped longitudinal ribs and bridge decks of orthotropic steel bridge deck units based on tungsten argon arc welding remelting process Construction method of fatigue strength of fillet welds of longitudinal connections. Background technique [0002] Since the introduction of orthotropic steel bridge decks after World War II, due to their light weight, large ultimate bearing capacity, low height of the steel box girder itself, easy processing and manufacturing, and short construction period, it has been widely used in large and medium-sized buildings in Europe, Japan and other countries. mid-span bridge. At the end of the last century, with the continuous maturity of the orthotropic steel bridge deck theory and the improvement of construction technology, more and more countries s...

AI Technical Summary

Problems solved by technology

As for the welded connection between the U-shaped longitudinal rib and the face plate, because it is distributed on the entire bridge deck, and the number is large, it is the part where the most fatigue cracks are found. The occurrence of fatigue cracks cannot be controlled, and a new construction process must be found to ensure the quality of the weld, thereby improving the fatigue strength of the welded joint and prolonging the fatigue life

[0005] The test and application of using argon tungsten arc welding remelting process to improve the fatigue strength of welded joints have been reported and recommended by the International Welding Association. However, from the application situation, most of them are used in important welds of important components. The shape and structure of the heterogeneous steel bridge deck unit are basically the same, and the application of a large number of batch components has not been reported. Therefore, it is necessary to find a construction method that can adapt to large-scale production without affecting the construction progress of the project.

Images