An orthotropic deck plate consists of a thin steel plate, stiffened by a series of closely spaced longitudinal stiffeners and transverse crossbeams. Although in use for over 50 years now, this deck type is still the preferred alternative for medium to long span bridges, especially due its low self-weight. In fact 7 out of 10 world's longest bridges are equipped with an orthotropic deck. Unfortunately, it is prone to the phenomenon of fatigue, particularly in the vicinity of the many welded connections. Seen the lack of relevant literature and the importance in the fatigue verification of accurate design stress spectra, it was agreed that more field research was necessary. As part of a research programme, a series of measurements were carried out on different bridges with orthotropic plated deck, subject to both road and railway traffic. This paper describes the test procedure, the challenges and the advantages of the method used and analyses the results in view of the fatigue problem. It especially focuses on the differences found for equal geometries but different loads. The recordings have demonstrated a significant difference between road and railway traffic for the locations and have proven that, from a fatigue point of view, high-speed train traffic is not severe, compared to freight train traffic. The cope hole in the crossbeam web around the outer longitudinal stiffeners proves to be determining in the fatigue verification for railroad bridges due to a combination of rectangular framework action and local load introduction at this location. In addition the stress pattern is highly non-linear in the vicinity of the cope-hole edge, raising the stress values up to 40% within a few millimetres adjacent to the edge. Furthermore, for ballasted railway tracks, the longitudinal stiffener to deckplate joint is free from any fatigue problem due to the load dispersal, whereas this is the most stressed location for road bridges. This type of results can only be achieved through continuous high frequency strain gauge measurements.
Fatigue assessment of orthotropic bridge decks through high frequency strain gauge measurements
Ermüdungsbewertung orthotroper Brückenfahrbahntafeln mittels Hochfrequenz-Dehnungsmessstreifen
2004
4 Seiten, 6 Bilder, 2 Tabellen
Conference paper
English
Wearing Surfaces for Orthotropic Steel Bridge Decks
Transportation Research Record | 1999
|British Library Conference Proceedings | 2003
|Analysis of Isotropic and Orthotropic Sandwich Bridge Decks
Springer Verlag | 2020
|Part 4 -- Bridges - Wearing Surfaces for Orthotropic Steel Bridge Decks
Online Contents | 1999
|