Steel bridge deck U rib butt joint fatigue strengthening structure and method based on bonding

Abstract

The invention relates to a steel bridge deck U-rib butt joint fatigue strengthening structure and method based on bonding. The strengthening structure comprises a fiber reinforced composite material layer wrapping a U-rib butt joint and a bonding layer arranged between the fiber reinforced composite material layer and the U-rib butt joint. The strengthening method comprises the steps of surface treatment, fiber reinforced composite material adhesion and maintenance. Compared with the prior art, a steel bridge deck U rib butt joint is subjected to fatigue strengthening through an adhesive and the fiber reinforced composite material, the stress amplitude of a structural damage part can be effectively reduced, expansion of fatigue cracks is inhibited, and the structural fatigue life is greatly prolonged; the strengthening structure improves the stress condition of a defect part of an original structure without weakening the rigidity of the cross section and introducing a new fatigue source; the strengthening structure adopts an adhesive combination mode, is simple and convenient to construct, and has high space adaptability to strengthening of weld cracks and uneven conditions such asfolded plates and curved surface steel plates.

Description

technical field [0001] The invention belongs to the technical field of steel bridge deck reinforcement, and relates to a bonding-based fatigue reinforcement structure and method for U-rib butt joints of steel bridge decks. Background technique [0002] The orthotropic steel bridge deck is a structure with complex mechanical properties welded by mutually perpendicular top plates, longitudinal stiffeners (U ribs) and diaphragms. It is widely used in In various types of bridge structures such as cable-bearing bridges and long-span steel box girders at home and abroad. At present, the longitudinal stiffener connection methods of orthotropic steel bridge decks include steel liner butt welding and high-strength bolt connection. The butt welding connection has simple structure, convenient fabrication, high construction redundancy, and good economy, but it is inevitable that there will be welding forms such as overhead welding and vertical welding that are difficult to ensure weldi...

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Problems solved by technology

For example: using the crack stop method to weaken the cross-section, in addition, if the position of the crack stop hole cannot be accurately located at the crack tip, the crack will continue to expand, resulting in the failure of the crack stop hole; while the crack welding method is used when grinding the weld seam It takes a lot of time, requires high construction quality, and it is easy to introduce residual stress that is unfavorable to fatigue resistance at the weld toe; for the steel plate reinforcement method, it is inevitable that new steel plates will be welded or bolted during the connection process Therefore, new fatigue cracks are easy to occur. At the same time, in order to install the splicing plates and bolts inside the U-rib, it is necessary to open a hand hole at the lower end of the U-rib, which will damage and weaken the original structural section. Moreover, the arc section between the lower flange of the U rib and the web cannot be installed with a reinforcing steel plate, and it is difficult to prevent the further expansion of fatigue cracks here.

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