Strengthening of Steel Connections in a 92-Year-Old Railway Bridge Using Prestressed CFRP Rods: Multiaxial Fatigue Design Criterion
| Autor: | Elyas Ghafoori, Masoud Motavalli, Hossein Heydarinouri, Alain Nussbaumer |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
life
Engineering pre-stress levels business.industry 0211 other engineering and technologies 020101 civil engineering 02 engineering and technology Building and Construction Structural engineering wedge-barrel anchor post-tensioning Bridge (interpersonal) Rod 0201 civil engineering 021105 building & construction multiaxial fatigue business strengthening bridge connections carbon fiber-reinforced polymer rod Civil and Structural Engineering |
| Zdroj: | Journal of Bridge Engineering. 26 |
| ISSN: | 1943-5592 1084-0702 |
| DOI: | 10.1061/(asce)be.1943-5592.0001714 |
| Popis: | This paper presented a new retrofit system for strengthening the stringer-to-floor-beam double-angle connections in a 92-year-old riveted railway bridge in Switzerland, using prestressed carbon fiber-reinforced polymer (CFRP) rods. The strengthening system transmitted the forces purely through friction, with minimum interference with bridge traffic. The system consisted of two components: a newly developed mechanical wedge-barrel anchor to hold the prestressed CFRP rod and a clamping system attaching the stringer flange. The strengthening system reduced the out-of-plane deformation of the connections, resulting in a reduction in the distortion-induced stresses in the connections. The short-term bridge measurements showed that the application of a total prestressing force of 100 kN reduced the dominant mean stress in the connection hotspot by 47% (from 22.9 to 10.9 MPa) under the passage of passenger trains, whereas the stress range remained unchanged. Using the modified Wohler curve method (MWCM) as a critical plane-based multiaxial fatigue model, the strengthening system was observed to reduce the multiaxial mean stress parameter by 30% under the passenger train loads. The long-term monitoring of the strengthening system, using a wireless sensor network (WSN) system, indicated no prestress loss in the CFRP rods during the seven-month period since its installation. |
| Databáze: | OpenAIRE |
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