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Collin, P., Lagerqvist, O., Veljkovic, M. & Elfgren, L. (2024). Professor Bernt Johansson and LTU: Development of Steel Structures in northern Sweden. Luleå: Luleå University of Technology
Open this publication in new window or tab >>Professor Bernt Johansson and LTU: Development of Steel Structures in northern Sweden
2024 (English)Other (Other academic)
Abstract [en]

Bernt Johansson, born in Stockholm in 1942. earned his MSc in Civil Engineering from the Royal Institute of Technology in 1961. He worked as a consultant engineer and continued his studies and presented his PhD thesis in 1976 on the stability of box-girder beams. In 1985 he was recruited to Luleå University of Technology to start research on steel structures. He initiated work with thin-walled structures, high strength steel and composite structures collaborating with industry. He played a pivotal role in the development of Swedish and European design codes. He supervised many master’s, licentiate, and PhD students. He passed away in 2017

Place, publisher, year, pages
Luleå: Luleå University of Technology, 2024. p. 9
Keywords
stability, thin-walled steel structures, composite structures, high strength steel, building codes.
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-108357 (URN)
Available from: 2024-07-18 Created: 2024-07-18 Last updated: 2025-02-04Bibliographically approved
Vestman, V., García Jordan, F. J., Santamaría Caballero, G. & Collin, P. (2023). Lateral trusses between I-girders introducing torsional stiffness to a composite bridge in Guatemala. In: Milan Veljkovic; Trayana Tankova; Florentia Kavoura; Andreas Taras; Vlad Silvestru; Valentino Vigneri (Ed.), Eurosteel 2023: September 12–14, 2023, Amsterdam. Paper presented at 10th Eurosteel conference, (EUROSTEEL2023), Amsterdam, Netherlands, September 12-14, 2023 (pp. 1049-1054). John Wiley & Sons
Open this publication in new window or tab >>Lateral trusses between I-girders introducing torsional stiffness to a composite bridge in Guatemala
2023 (English)In: Eurosteel 2023: September 12–14, 2023, Amsterdam / [ed] Milan Veljkovic; Trayana Tankova; Florentia Kavoura; Andreas Taras; Vlad Silvestru; Valentino Vigneri, John Wiley & Sons, 2023, p. 1049-1054Conference paper, Published paper (Refereed)
Abstract [en]

The ways of designing and building steel girder bridges with a composite concrete deck vary much between different parts of the world. A bridge system with twin steel I-girders or a concept with multiple (more than two) girders can be used. The design and use of details and secondary systems also vary a lot. In order to give horizontal stabilization and distribute horizontal loads, bracing between the I-girders bracings are often used. Although not so common, the bracing can also be used to distribute vertical loads between the main girders. To describe and to analyze the possible impact from using a lateral bracing, this paper describes the design of a curved bridge in Guatemala City and its challenges. The new Bridge over the Pinula River is designed as a steel-concrete composite bridge with multiple steel girders with a concrete deck on top and has lateral bracing between the girders. The bridge is used as a case study to analyze the impact from a lateral bracing system on the vertical load distribution between the longitudinal girders. The bridge was designed with lateral bracing between the top flanges along the whole bridge and with bracing between the lower flanges near the supports. The case study shows that the distribution of eccentric vertical loads between the longitudinal girders can be improved by using lateral bracing between the lower flanges for multiple girders. In some cases, it may not be beneficial to use lateral bracings along the whole bridge length, like for example this bridge. In this case due to the governing design cases in the construction stages where these bracings influenced the torsional stiffness of the bridge in such way that an unfavorable distribution of the support reactions between the six girders at some supports was achieved.

Place, publisher, year, edition, pages
John Wiley & Sons, 2023
Series
c/e papers - Proceedings in civil engineering, E-ISSN 2509-7075 ; 6
Keywords
Bridge, I-girder, lateral bracing, launching, steel-concrete composite, torsional stiffness
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-96210 (URN)10.1002/cepa.2684 (DOI)
Conference
10th Eurosteel conference, (EUROSTEEL2023), Amsterdam, Netherlands, September 12-14, 2023
Note

Full text license: CC BY

Available from: 2023-03-22 Created: 2023-03-22 Last updated: 2023-11-24Bibliographically approved
Vestman, V., Collin, P., Lilja, H., Tirkkonen, T., Peltomaa, M., Jordan, J., . . . Hällmark, R. (2022). Horizontal bracing in steel I-girder bridges with composite concrete decks. In: František Wald, Pavel Ryjáček (Ed.), IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures - Report, International Association for Bridge and Structural Engineering: . Paper presented at IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures, Prague, Czech Republic, May 25-27, 2022 (pp. 1684-1690). International Association for Bridge and Structural Engineering
Open this publication in new window or tab >>Horizontal bracing in steel I-girder bridges with composite concrete decks
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2022 (English)In: IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures - Report, International Association for Bridge and Structural Engineering / [ed] František Wald, Pavel Ryjáček, International Association for Bridge and Structural Engineering, 2022, p. 1684-1690Conference paper, Published paper (Refereed)
Abstract [en]

This paper treats the use of horizontal trusses between the bottom flanges of new I-girder bridges, to create a box-like behaviour. In contrast to the general vertical cross frames of an I-girder bridge, the horizontal trusses bring along substantial torsional stiffness of the cross section of a bridge. The concept gives large advantages when it comes to fatigue caused by eccentric loading, since the I-girders will share the load more equally. The concept is exemplified by bridges in Finland, Guatemala and France, and some design aspects as well as practical aspects are discussed. 

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering, 2022
Keywords
box action, bracings, bridge fatigue, I-girders bridges, trusses
National Category
Reliability and Maintenance
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-92201 (URN)10.2749/prague.2022.1684 (DOI)2-s2.0-85133509021 (Scopus ID)
Conference
IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures, Prague, Czech Republic, May 25-27, 2022
Note

ISBN for host publication: 978-3-85748-181-9

Available from: 2022-07-19 Created: 2022-07-19 Last updated: 2023-09-13Bibliographically approved
Vestman, V., Collin, P. & Hällmark, R. (2022). Strengthening of a Composite I-girder Bridge by Trusses Introducing Box-Action. In: : . Paper presented at 10th International symposium on steel bridges – for A Green Planet, September 20 - 22, 2022 Istanbul, Turkey.
Open this publication in new window or tab >>Strengthening of a Composite I-girder Bridge by Trusses Introducing Box-Action
2022 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

The increased amount of traffic and the increasingly heavier loads on the road network push the existing infrastructure to its design limit. Bridges, which are an important part of the road network, need to be adopted to the new traffic demands regarding both the load capacity and the fatigue limit state, FLS. Steel-concrete composite bridges, with twin steel I-girders, is a common bridge type in the Nordic countries. These bridges are often designed using beam models, assuming that the concrete deck is a statically determinate structure supported on the two steel girders in the transversal direction. This assumption implies that the most loaded girder can sometimes be subjected to even more than 100% of an eccentric load, e.g., the traffic loads in the design codes. If the girders are strengthened to be able to share the eccentric loads more equally, it would have a significant impact on the load capacity, especially for the fatigue limit state. By introducing horizontal trusses between the bottom flanges of the girders, making the cross-section act more like a box-girder, the torsional stiffness will increase so that the girders will share the eccentric loads more equally. The bracing system of the trusses can be designed in different shapes, each of them with pros and cons for the existing bridge structure. In this paper, the effects from different shapes of the bracing are evaluated of a single span I-girder composite bridge. The increased torsional stiffness and the change of the internal shear flow will increase the load capacity of the steel girders.

Keywords
bridge, steel-concrete composite, I-girder, case study, horizontal trusses, torsional stiffness, strengthening, composite bridges
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-96211 (URN)
Conference
10th International symposium on steel bridges – for A Green Planet, September 20 - 22, 2022 Istanbul, Turkey
Available from: 2023-03-22 Created: 2023-03-22 Last updated: 2023-09-05
Vestman, V., Collin, P. & Oudomphanh, S. (2022). Torsion of a Norwegian bridge with partial box-action - a case study. In: IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures - Report: . Paper presented at IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures, Prague, Czech Republic, May 25-27, 2022. International Association for Bridge and Structural Engineering
Open this publication in new window or tab >>Torsion of a Norwegian bridge with partial box-action - a case study
2022 (English)In: IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures - Report, International Association for Bridge and Structural Engineering, 2022Conference paper, Published paper (Refereed)
Abstract [en]

Some old bridges have a truss between the bottom flanges not intended for torsional effects but for transferring horizontal forces. This paper describes the effects of the truss on torsion for a Norwegian three span bridge from 1967, without composite action. Furthermore, the effects of post-installed shear connectors are investigated. For composite bridges without intended composite action in bending, the effects of the slab preventing the top flanges from moving laterally should not be ignored, since this is important for the deformations of the girders under eccentric loading. Furthermore, the load distribution between the girders for an eccentric load is significantly enhanced if the horizontal truss is considered. The paper also investigates and presents the effects of post-installed shear connectors, with respect to bending stresses in the bottom flanges (moderate effects) and the top flange (large effects). 

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering, 2022
Keywords
Composite bridge, strengthening, horisontal bracing, composite action, box-action
National Category
Other Civil Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-91424 (URN)2-s2.0-85133548852 (Scopus ID)
Conference
IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures, Prague, Czech Republic, May 25-27, 2022
Available from: 2022-06-15 Created: 2022-06-15 Last updated: 2023-09-05Bibliographically approved
Vestman, V., Collin, P., Hällmark, R. & Arason, M. (2021). Monitoring of a Norwegian steel-concrete bridge strengthening forcomposite action. In: Snijder H.H.; De Pauw, B.; van Alphen, S.; Mengeot, P. (Ed.), IABSE Congress Ghent 2021: Structural Engineering for Future Societal Needs. Paper presented at IABSE Congress 2021: Structural Engineering for Future Societal Needs, Ghent, Belgium [Online], September 22-24, 2021 (pp. 1709-1717). International Association for Bridge and Structural Engineering (IABSE)
Open this publication in new window or tab >>Monitoring of a Norwegian steel-concrete bridge strengthening forcomposite action
2021 (English)In: IABSE Congress Ghent 2021: Structural Engineering for Future Societal Needs / [ed] Snijder H.H.; De Pauw, B.; van Alphen, S.; Mengeot, P., International Association for Bridge and Structural Engineering (IABSE) , 2021, p. 1709-1717Conference paper, Published paper (Refereed)
Abstract [en]

Traffic density and vehicle weight have been increasing over time, which implies that many existing road bridges were not designed for the high service loads and the increased number of load cycles that they are exposed to today. One way to increase the traffic load capacity of non-composite steel-concrete bridges is to use post-install shear connectors and one type of shear connector is the coiled spring pin. This type of connector has advantages for strengthening of existing bridges, since it enables an installation from below while the bridge is still in service and does not bring along removal of concrete and pavement, nor welding to the top flange.

This paper describes one ~50 years old Norwegian single span steel-concrete bridge that was strengthened with post-installed coiled spring pins. The strengthening method and the design procedure are presented, along with the results from a field monitoring on Sagstu bridge, performed to evaluate the behaviour of the strengthened structure. The results show that the coiled spring pins counteract the slip and bring along a very good degree of composite action.

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering (IABSE), 2021
Series
IABSE Congress Reports ; 21
Keywords
composite bridges, coiled spring pins, monitoring, post-installed shear connectors
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-87390 (URN)10.2749/ghent.2021.1709 (DOI)2-s2.0-85119058194 (Scopus ID)
Conference
IABSE Congress 2021: Structural Engineering for Future Societal Needs, Ghent, Belgium [Online], September 22-24, 2021
Note

ISBN för värdpublikation: 978-3-85748-176-5

Available from: 2021-10-06 Created: 2021-10-06 Last updated: 2023-09-05Bibliographically approved
Svensson, D., Vestman, V. & Collin, P. (2021). Slussen – the lock of Stockholm. In: H. H. (Bert) Snijder; Bart De Pauw; Sander van Alphen; Pierre Mengeot (Ed.), IABSE Congress Ghent 2021: Structural Engineering for Future Societal Needs. Paper presented at IABSE Congress 2021: Structural Engineering for Future Societal Needs, Ghent, Belgium, September 22-24, 2021 (pp. 1882-1890). International Association for Bridge and Structural Engineering (IABSE)
Open this publication in new window or tab >>Slussen – the lock of Stockholm
2021 (English)In: IABSE Congress Ghent 2021: Structural Engineering for Future Societal Needs / [ed] H. H. (Bert) Snijder; Bart De Pauw; Sander van Alphen; Pierre Mengeot, International Association for Bridge and Structural Engineering (IABSE) , 2021, p. 1882-1890Conference paper, Published paper (Refereed)
Abstract [en]

Slussen is situated in the inner city of Stockholm just south of the world heritage site Gamla Stan and the royal castle. This historical site and also second biggest traffic and transportation hub in Stockholm is at the moment undergoing a complete refurbishment due to new demands and requirements and due to the fact that the former traffic plant was in a very bad shape with severe settlements and outworn concrete structures. The old traffic structure from the 1930´s is replaced by a modern urban space and transportation node designed by Foster + Partner and Berg arkitekter, adopted to demands and requirements of the future i.e. increased capacity for pedestrians and cyclists, heavily increased discharge capacity for Lake Mälaren, attractive areas for the public close to the water and several restaurants and cafés.

This mega project ( 1.4 Billion) cannot be described completely in a single paper so therefore twoobjects of special technical interest have been chosen and are described below: the water regulationsystem as well as the unique 3.400 Tons steel bridge, transported in one piece from China.

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering (IABSE), 2021
Keywords
Large infrastructure projects, lock canal, steel bridge, orthotropic deck & sea transport
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-87391 (URN)10.2749/ghent.2021.1882 (DOI)2-s2.0-85119060528 (Scopus ID)
Conference
IABSE Congress 2021: Structural Engineering for Future Societal Needs, Ghent, Belgium, September 22-24, 2021
Available from: 2021-10-06 Created: 2021-10-06 Last updated: 2023-09-05Bibliographically approved
Venturi, G., Simonsson, P. & Collin, P. (2021). Strengthening old steel railway bridges: a review. In: H. H. (Bert) Snijder; Bart De Pauw; Sander van Alphen; Pierre Mengeot (Ed.), IABSE Congress Ghent 2021: Structural Engineering for Future Societal Needs. Paper presented at IABSE Congress 2021: Structural Engineering for Future Societal Needs, Ghent, Belgium, September 22-24, 2021 (pp. 1718-1727). International Association for Bridge and Structural Engineering (IABSE)
Open this publication in new window or tab >>Strengthening old steel railway bridges: a review
2021 (English)In: IABSE Congress Ghent 2021: Structural Engineering for Future Societal Needs / [ed] H. H. (Bert) Snijder; Bart De Pauw; Sander van Alphen; Pierre Mengeot, International Association for Bridge and Structural Engineering (IABSE) , 2021, p. 1718-1727Conference paper, Published paper (Refereed)
Abstract [en]

Strengthening old bridges is an increasingly relevant strategy for risk prevention and operation continuity in management of infrastructures. Transportation networks are subjected to progressively stricter environmental and load conditions, leading to a growing number of deficient structures, also due to aging and deterioration. However, employable resources are finite, from both economical and environmental points of view. For these reasons, strengthening opportunities should be considered as a viable option, improving bridges behaviour with low economical and environmental impact. With this perspective, a selection of some of the most interesting strengthening techniques for old truss railway bridges is presented. To address effective solutions, the most frequent problems in old truss railway bridges are first presented. Literature analysis and experts’ interviews were conducted and compared to results obtained from a representative bridge cluster. Different solutions addressing highlighted problems are then collected and qualitatively evaluated, in terms of efficacy on structural behaviour and typical construction requirements. Finally, general remarks and recommendations based on collected evidence are presented.

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering (IABSE), 2021
Keywords
truss bridges, railway bridges, steel bridges, strengthening
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-87569 (URN)10.2749/ghent.2021.1718 (DOI)2-s2.0-85119084032 (Scopus ID)
Conference
IABSE Congress 2021: Structural Engineering for Future Societal Needs, Ghent, Belgium, September 22-24, 2021
Available from: 2021-10-21 Created: 2021-10-21 Last updated: 2023-09-05Bibliographically approved
Hällmark, R., Nilforoush, R., Vestman, V. & Collin, P. (2021). Testing of composite girders with coiled spring pin shear connectors. In: H. H. (Bert) Snijder; Bart De Pauw; Sander van Alphen; Pierre Mengeot (Ed.), IABSE Congress Ghent 2021: Structural Engineering for Future Societal Needs. Paper presented at IABSE Congress 2021: Structural Engineering for Future Societal Needs, Ghent, Belgium, 22-24 September, 2021 (pp. 1700-1708). International Association for Bridge and Structural Engineering (IABSE)
Open this publication in new window or tab >>Testing of composite girders with coiled spring pin shear connectors
2021 (English)In: IABSE Congress Ghent 2021: Structural Engineering for Future Societal Needs / [ed] H. H. (Bert) Snijder; Bart De Pauw; Sander van Alphen; Pierre Mengeot, International Association for Bridge and Structural Engineering (IABSE) , 2021, p. 1700-1708Conference paper, Published paper (Refereed)
Abstract [en]

Today, steel girder bridges with concrete deck slabs are generally constructed as steel-concrete composite structures, to utilize the material and the structural parts in an efficient way. However, many existing bridges constructed before the early 1980´s were designed without shear connectors at the steel-concrete interface. With increasing traffics loads and higher amount of load cycles, there is sometimes a need to strengthen these bridges. One way to increase the bending moment capacity is to create composite action by post-installation of shear connectors. The authors have studied the concept of strengthening by post-installed shear connectors, with a focus on a connector called coiled spring pin. This paper presents the results from the first beam tests performed with this kind of shear connector. In line with the previous push-out tests, the test results indicate a very ductile shear connection, with a potential to be a material- and cost-efficient strengthening alternative.

Place, publisher, year, edition, pages
International Association for Bridge and Structural Engineering (IABSE), 2021
Keywords
bridge, strengthening, rehabilitation, shear connector, test, composite girder, coiled spring pin
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-87385 (URN)10.2749/ghent.2021.1700 (DOI)2-s2.0-85119084525 (Scopus ID)
Conference
IABSE Congress 2021: Structural Engineering for Future Societal Needs, Ghent, Belgium, 22-24 September, 2021
Funder
Swedish Transport AdministrationSvenska Byggbranschens Utvecklingsfond (SBUF)
Available from: 2021-10-05 Created: 2021-10-05 Last updated: 2023-09-05Bibliographically approved
Pipinato, A., Geier, R., Ivanov, S., Rebelo, C., Collin, P. & Hällmark, R. (2021). UHPFRC strengthening strategies on existing steel and steel-concrete bridges. In: Hiroshi Yokota; Dan M. Frangopol (Ed.), Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations: Proceedings of the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), June 28-July 2, 2020, Sapporo, Japan. Paper presented at 10th International Conference on Bridge Maintenance, Safety, and Management (IABMAS2020), Sapporo, Japan [ONLINE], April 11-18, 2021 (pp. 598-605). CRC Press
Open this publication in new window or tab >>UHPFRC strengthening strategies on existing steel and steel-concrete bridges
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2021 (English)In: Bridge Maintenance, Safety, Management, Life-Cycle Sustainability and Innovations: Proceedings of the Tenth International Conference on Bridge Maintenance, Safety and Management (IABMAS 2020), June 28-July 2, 2020, Sapporo, Japan / [ed] Hiroshi Yokota; Dan M. Frangopol, CRC Press, 2021, p. 598-605Conference paper, Published paper (Refereed)
Abstract [en]

The overall traffic density and the allowed vehicle weights have been increasing over the last decades. As a response, new roads and railway lines are continuously planned and built. On the other hand, the existing bridges must also be capable of dealing with the increasing traffic volume and the increasing vehicle weights. Many existing bridges were not originally designed for the high traffic loads and todays traffic volume. To cope with the increased loads and load frequencies, the aged structures need repair and strengthening. To avoid the replacement of existing structures, the overall objective is to improve the structural performance of existing steel and steel-concrete bridges by providing innovative and well documented repair and strengthening solutions to bridge designers and road/railway-administrations in Europe. In this paper the use of UHPFRC as a solution for bridge and viaduct repair and strengthening has been presented.

Place, publisher, year, edition, pages
CRC Press, 2021
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-93907 (URN)10.1201/9780429279119-78 (DOI)000844440300078 ()2-s2.0-85117582597 (Scopus ID)
Conference
10th International Conference on Bridge Maintenance, Safety, and Management (IABMAS2020), Sapporo, Japan [ONLINE], April 11-18, 2021
Note

ISBN för värdpublikation: 978-0-367-23278-8 (tryckt), 978-0-429-27911-9 (digital)

Available from: 2022-11-08 Created: 2022-11-08 Last updated: 2023-11-10Bibliographically approved
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Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-8353-9225

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