| 1. |
- Täljsten, Björn, 1961-, et al.
(author)
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Assessment of prestressed concrete bridges - challenges
- 2020
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In: IABSE Symposium, Wroclaw 2020. - Zürich : International Association For Bridge And Structural Engineering (IABSE). ; , s. 487-494
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Conference paper (peer-reviewed)abstract
- Prestressed concrete bridges are important parts of our infrastructure. They are susceptible to different kinds of deterioration processes. Examples of damages and deficiencies are cracking, corrosion, voids, bond loss, reduction of cover layer, delamination, fatigue and loss of stiffness and strength. This necessitates methods to continuously assess their condition in order to avoid problems that might lead to shorter service life or reduction of structural integrity. Many of the existing prestressed bridges in Europe are now approaching their design life length. However, with proper and continuous inspection, monitoring and assessment, we may plan proactive maintenance and the structural safety can be assured or – if necessary - increased. This will save both money and decrease the environmental impact of the structure.
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| 2. |
- Enochsson, Ola, et al.
(author)
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Assessment and condition monitoring of a concrete railway bridge in Kiruna, Sweden
- 2006
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In: Bridge maintenance, safety, management, life-cycle performance and cost. - London : Taylor and Francis Group. - 0415403154
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Conference paper (peer-reviewed)abstract
- A two-span railway concrete trough bridge over Luossajokk in Kiruna in northern Sweden has been studied. The owner wanted to increase the axle loads from 250 to 300 kN in order to reduce freight costs for iron ore. Examples are given of methods used and results obtained from the assessment where bending, shear and fatigue were studied. Material properties, loads and load carrying capacity were evaluated using deterministic and probabilistic methods. It was shown that the bridge could carry the higher loads with a safety index β > 4.7 for reasonable assumptions of the load distributions. A measurement system was installed to check the actual level of critical strains and the worst positions of the train. Results are also given from a condition monitoring program 2001-2006, launched to periodically check the development of strains with time.
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| 3. |
- Ekberg, Anders, 1967, et al.
(author)
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Upgrading of freight railways to meet operational and market demands
- 2018
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In: Proceedings of 7th Transport Research Arena TRA 2018.
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Conference paper (peer-reviewed)abstract
- The European objective of a modal shift of freight transports to railways will require extensive upgrading of existing railway lines since very few dedicated freight railways are currently being built and existing lines were built for traffic demands at the time of construction. A transition to increased and enhanced railway freight operations can therefore be costly and complicated. To minimize negative effects, a guideline for upgrading was developed within the Capacity4Rail project. The current paper presents the major findings from this guideline. In particular it outlines different upgrading possibilities and their implications, and details structured approaches to upgrading analyses. Setting out from the Capacity4Rail handbook, the current paper discusses possibilities for upgrading of substructures, bridges, tunnels, and the track structure. In these areas, an overview of challenges and possibilities is presented together with examples of experience from operational upgrading. The paper concludes that freight line upgrading using a more streamlined approach as outlined in the guideline is a necessity if EU objectives on modal shifts in transportation are to be met. Further, it demonstrates why a political drive is necessary to increase efforts to upgrade freight lines.
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| 4. |
- Elfgren, Lennart, 1942-, et al.
(author)
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Load-testing used for quality control of bridges
- 2018
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In: Quality Specifications for Roadway Bridges. ; , s. 1-6
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Conference paper (peer-reviewed)abstract
- Load testing is a way to control the capacity and function of a bridge. Methods and recommendations for load testing are described and examples are given form tests carried out. In order not to damage the bridge being tested, the load must be limited, often to be within the serviceability limit state (SLS). Numerical models can be calibrated by load tests and then be used to check the carrying capacity for higher loads than what has been tested. Need for further work and recommendations are discussed. By effective planning costs can be saved and a more sustainable use of bridges can be obtained.
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| 5. |
- He, Guojing, 1964-, et al.
(author)
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Assessment of a railway concrete arch bridge by numerical modelling and measurements
- 2008
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In: <em>Bridge Maintenance, Safety, Management, Health Monitoring and Informatics</em>. - Leiden : CRC Press. ; , s. 3733-3742
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Conference paper (peer-reviewed)abstract
- Two main railway concrete arch bridges have been investigated in northern Sweden: the Vindel Bridge over the Vindel River with a span of 110 m and the Långforsen Bridge over the Kalix River with a span of 90 m. The bridges were constructed in the 1950s with similar designs. In order to investigate the possibility to increase the axle load from 225 kN to 250kN, two 3-D Finite Element models with shell elements were developed and two field tests were carried out with passing trains and ambient vibrations. The measurement frequencies and mode shapes were studied with the stochastic subspace identification method in the time domain. Based on a comparison of the predictions of the FE analyses and the results of the field tests, the FE models were updated. It was found that it was possible to make good predictions of the actual dynamic response with reasonable assumptions of material properties and joint stiffness in the structure.
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| 6. |
- Bagge, Niklas, 1987-, et al.
(author)
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Assessment of concrete bridges - Prestress forces : Experiences from full-scale testing to failure of a bridge in Kiruna
- 2017
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In: Proceedings of the 23rd Nordic Concrete Research Symposium, Oslo, Norway: Nordic Concrete Federation. - Oslo : Nordic Concrete Federation. ; , s. 267-270
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Conference paper (peer-reviewed)abstract
- To calibrate methods for condition assessment of prestressed concrete (PC) bridges, tests were carried out on a 55 year old five-span bridge with a length of 121 m in Kiruna in northern Sweden. Both non-destructive and destructive full-scale tests were performed. This paper presents results regarding the residual forces in the prestressed reinforcement.
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| 7. |
- Bell, Brian, et al.
(author)
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Sustainable Bridges – Past and Future. Reflections on a European Project 2003 – 2007
- 2023
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In: IABSE Congress 2023 New Delhi, Engineering for Sustainable Development. - : International Association for Bridge and Structural Engineering. ; , s. 690-698
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Conference paper (peer-reviewed)abstract
- Twenty years ago, in 2003, a European project was started to increase the sustainability of existing railway bridges. This paper summarises what was achieved and looks ahead. Nine Working Packages were organized: (1) Background material; (2) Guidance by stakeholders; (3) Condition Assessment and Inspection Guidelines; (4) Loads, Capacity and Resistance Guidelines; (5) Monitoring Guidelines; (6) Repair and Strengthening Guidelines; (7) Demonstration with Field testing of Bridges; (8) Demonstration on Monitoring on Bridges; and (9) Training and Dissemination.Some of the main results (from 4 Guidelines and 47 Background documents) are highlighted and some experiences, conclusions and thoughts about the future are given. Hidden strengths and weaknesses are discussed, analyses and codes for assessment can be improved, new monitoring and strengthening methods are available and life length can be prolonged.
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| 8. |
- Bell, Brian, et al.
(author)
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Sustainable Bridges - Past and Future Reflections on a European Project 2003-2007
- 2023
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In: IABSE Congress, New Delhi 2023: Engineering for Sustainable Development, Report. ; , s. 690-698
-
Conference paper (peer-reviewed)abstract
- Twenty years ago, in 2003, a European project was started to increase the sustainability of existing railway bridges. This paper summarises what was achieved and looks ahead. Nine Working Packages were organized: (1) Background material; (2) Guidance by stakeholders; (3) Condition Assessment and Inspection Guidelines; (4) Loads, Capacity and Resistance Guidelines; (5) Monitoring Guidelines; (6) Repair and Strengthening Guidelines; (7) Demonstration with Field testing of Bridges; (8) Demonstration on Monitoring on Bridges; and (9) Training and Dissemination Some of the main results (from 4 Guidelines and 47 Background documents) are highlighted and some experiences, conclusions and thoughts about the future are given. Hidden strengths and weaknesses are discussed, analyses and codes for assessment can be improved, new monitoring and strengthening methods are available and life length can be prolonged.
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| 9. |
- Blanksvärd, Thomas, et al.
(author)
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Test to failure of a steel truss bridge – Calibration of assessment methods
- 2014
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In: Bridge Maintenance, Safety, Management and Life Extension. - London : CRC Press, Taylor & Francis Group. - 9781138001039 - 9781315760698 ; , s. 1076-1081
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Conference paper (peer-reviewed)abstract
- The steel truss railway bridge at Åby River was built in 1957 with a span of 32 m (105 feet). In 2012 it was replaced by a new steel beam bridge and the old bridge was placed beside the river. It was tested to failure to study its remaining load-carrying capacity in September 2013. The test was carried out by Luleå University of Technology by commission from Trafikverket as a part of the European Research Project MAINLINE (www.mainline-project.eu). In this paper some preliminary results are given. Two hydraulic jacks, anchored by cables to the bedrock, pulled the bridge downwards. The bridge remained elastic up to about three times the original design load and the load could then be almost doubled with substantial yielding deformations before a buckling failure appeared in the top girders for a load of ca. 11 MN (1000 short tons) for a midpoint deflection of ca. 0, 2 m (8 inches). No brittle or fatigue failure in any of the joints appeared and the bridge proved to behave in a ductile way with a substantial hidden capacity.
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| 10. |
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