Bridge over Åby River: evaluation of full scale testing

The former Bridge over Åby River has played a significant role in Sweden's railway infrastructure. It was situated along the mainline, the only electrified railway line connecting the northern parts of Sweden with the southern parts and has therefore been crucial for both freight trains as well as for passenger trains. The Åby Bridge consisted of an unballasted open steel truss bridge which was constructed in 1955 got replaced together with the tracks during the autumn 2012. Before replacement of the bridge, LTU (Luleå University of Technology) performed measurements on the bridge to evaluate its status while it was still in service. This was carried out in 2012 between the 28th of August and the 13th of September. When the Åby Bridge got replaced, the old steel truss bridge was placed on the riverside to undergo further testing where it eventually was statically loaded to failure, which took place in 2013. These measurements were comprehensive, with strain gauges, LVDT's (Linear Voltage Displacement Transducer), temperature sensors as well as DIC (Digital Image Correlation) and accelerometers. One reason for the Åby Bridge being of particular interest is that there exists a similar "twin" bridge along the Ore line, the Bridge over Rautasjokk. The Ore line is the main route for transporting Iron ore from northern Sweden and stretches in the south from the steel mill in Luleå to the North, the harbor in Narvik, Norway. Due to the transportation of Iron ore, the Ore line is subdued to heavier traffic then the main line. There was placed a hope that the assessment of the Åby Bridge would provide information that could be used in order to keep the Rautasjokk Bridge in service. If the results from the Åby Bridge could provide information so that the bridge over Rautasjokk doesn't have to be replaced, cost savings can be made in the range of 15?20 million SEK. In 2015 was measurements carried out on the Rautasjokk Bridge, in order to verify findings provided from the Åby Bridge as well as fatigue assessment of critical details. Results indicated that the Åby bride was able to carry loads higher than four times the current regulated axle load along the line. Failure actions occurred in a ductile manner with lateral buckling of the top chord as the governing failure mode, which also was expected by numerical simulations. There were no observed failures in any of the riveted or welded connections.

Language

  • English

Media Info

  • Pagination: 134
  • Serial:
    • Technical report
    • Publisher: Luleå University of Technology, Sweden
    • ISSN: 1402-1536

Subject/Index Terms

Filing Info

  • Accession Number: 01664519
  • Record Type: Publication
  • Source Agency: Swedish National Road and Transport Research Institute (VTI)
  • ISBN: 9789175838236
  • Files: ITRD, VTI
  • Created Date: Mar 28 2018 10:28AM