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  • 1.
    Axelsson, Kennet B. E.
    et al.
    Högskolan i Luleå, Luleå tekniska universitet, Luleå University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Grennberg, Torsten
    Luleå tekniska universitet.
    Horrigmoe, Geir
    Luleå tekniska universitet.
    Johansson, Bernt
    Institutionen för Anläggningsteknik. Verksamhetsberättelse 1987/881988Report (Other (popular science, discussion, etc.))
  • 2.
    Axelsson, Kennet B. E.
    et al.
    Högskolan i Luleå, Luleå tekniska universitet, Luleå University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Grennberg, Torsten
    Luleå tekniska universitet.
    Horrigmoe, Geir
    Luleå tekniska universitet.
    Johansson, Bernt
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Institutionen för Anläggningsteknik, Verksamhetsberättelse 1988/891989Report (Other (popular science, discussion, etc.))
  • 3.
    Axelsson, Kennet B. E.
    et al.
    Högskolan i Luleå, Luleå tekniska universitet, Luleå University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Grennberg, Torsten
    Luleå tekniska universitet.
    Horrigmoe, Geir
    Luleå tekniska universitet.
    Johansson, Bernt
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Institutionen för Anläggningsteknik. Verksamhetsberättelse 1989/901990Report (Other (popular science, discussion, etc.))
  • 4.
    Axelsson, Kennet B. E.
    et al.
    Högskolan i Luleå, Luleå tekniska universitet, Luleå University of Technology.
    Johansson, Bernt
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Grennberg, Torsten
    Luleå tekniska universitet.
    Horrigmoe, Geir
    Luleå tekniska universitet.
    Institutionen för Anläggningsteknik. Verksamhetsberättelse 1990/911991Report (Other (popular science, discussion, etc.))
  • 5.
    Axelsson, Kenneth
    et al.
    Luleå tekniska universitet.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Bro1990In: Nationalencyclopedin, Höganäs: Bra Böcker , 1990, 320-324 p.Chapter in book (Other academic)
  • 6.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Bernspång, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Carolin, Anders
    Trafikverket.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Full-Scale Test to Failure of a Prestressed Concrete Bridge in Kiruna2014In: Nordic Concrete Research, ISSN 0800-6377, Vol. 50, 83-86 p.Article in journal (Refereed)
    Abstract [en]

    To calibrate methods for condition assessment of prestressed concrete (PC) bridges, tests are planned for a 50 year old five-span bridge with a length of 121 m in Kiruna in northern Sweden. Both non-destructive and destructive full-scale tests will be performed. This paper summarises the test programme, which comprises evaluation of the structural behaviour of the bridge, the residual forces in the prestressed steel, methods for strengthening using carbon fibre reinforced polymers (CFRP) and the shear resistance of the bridge slab.

  • 7.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Structural performance and failure loading of a 55 year-old prestressed concrete bridge2016In: Maintenance, Moniring, Safety, Risk and Resilience of Bridges and Bridge Networks / [ed] Tulio N. Bittencourt; Dan M. Frangopol; André T. Beck, London: CRC Press, Taylor & Francis Group, , 2016, 2225-2232 p.Conference paper (Refereed)
    Abstract [en]

    Tests have been performed at service- and ultimate load levels of a 55 year-old 121.5 m long prestressed concrete bridge. The purpose was to acquire data for enhanced assessment and calibration of such methods. At service-load several truck overpasses and the dynamic response were particularly studied. Some conclusions were: (a) less stiff load-deflection behavior was obtained with a finite element (FE) analysis compared to measurements and (b) good agreement was obtained for predicted and tested dynamic characteristics. The focus in the destructive tests was on the overall bridge behavior and the ultimate load-carrying capacity of the bridge’s girders and slab. The results were: (a) combined flexure-shear failure of girders occurred after reinforcement yielding for a load indicating an appreciable safety margin in relation to code predictions and (b) good agreement was obtained between FE analysis and the ultimate response and capacity of the tested bridge

  • 8.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Bernspång, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering. Norut Northern Research Institute, Narvik.
    Tu, Yongming
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering. College of Civil Engineering, Southeast University, Nanjing.
    Carolin, Anders
    Trafikverket, Trafikverket, Luleå.
    Performance of a prestressed concrete bridge loaded to failure2015In: IABSE Conference Geneva 2015: Structural Engineering: Providing Solutions to Global Challenges, Geneva: International Association for Bridge and Structural Engineering, 2015, 1088-1095 p.Conference paper (Other academic)
  • 9.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Instrumentation and Full-Scale Test of a Post-Tensioned Concrete Bridge2014In: Nordic Concrete Research, ISSN 0800-6377, Vol. 51, 63-83 p.Article in journal (Refereed)
    Abstract [en]

    To meet new demands, existing bridges might be in need for repair, upgrading or replacement. To assist such efforts a 55-year-old post-tensioned concrete bridge has been comprehensively tested to calibrate methods for assessing bridges more robustly. The programme included strengthening, with two systems based on carbon fibre reinforced polymers (CFRPs), failure loading of the bridge’s girders and slab, and determination of post-tension cables’ condition and the material behaviour. The complete test programme and related instrumentation are summarised, and some general results are presented. The measurements address several current uncertainties, thereby providing foundations for both assessing existing bridges’ condition more accurately and future research.

  • 10.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sundquist, Håkan
    Royal Institute of Technology.
    Carolin, Anders
    Trafikverket, Luleå.
    Assessment and failure test of a prestressed concrete bridge2017In: Life-Cycle of Engineering Systems: Emphasis on Sustainable Civil Infrastructure / [ed] Jaap Bakker; Dan M Frangopol; Klaas van Breugel, Leiden: CRC Press/Balkema , 2017, 1058-1063 p.Conference paper (Refereed)
    Abstract [en]

    Tests have been carried out at service- and ultimate load levels of a 55 year-old prestressed concrete girder bridge. The bridge, located in Kiruna, Sweden, was continuous in five spans with a total length of 121.5 m. The overall aim of the study was to determinate the accuracy of assessment methods for existing structures and to provide procedures for optimized assessment. Before the tests a 2D finite element (FE) analysis was performed to predict the behavior and load-carrying capacity of the bridge. In order to more accurately assess the bridge response a 3D FE model has now been developed. The actual loading history and material properties has been considered in the model. A Life Cycle Cost Assessment of the bridge has also been performed

  • 11.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Evaluation of residual prestress force in a concrete girder bridge2016In: IABSE CONGRESS, STOCKHOLM, 2016: Challenges in Design and Construction of an Innovativeand Sustainable Built Environment / [ed] Lennart Elfgren, Johan Jonsson, Mats Karlsson, Lahja Rydberg-Forssbeck and Britt Sigfrid, CH - 8093 Zürich, Switzerland, 2016, 222-229 p.Conference paper (Refereed)
    Abstract [en]

    When assessing the structural behaviour of prestressed concrete bridges, understanding the level of prestressing is crucial. However, for existing structures, this is usually an unknown parameter and the literature only describes a few methods of experimentally determining the residual prestress forces. For this paper, a non-destructive testing approach has been evaluated based on testing of a multi-span continuous girder bridge. The method, consisting of in-situ measurements in combination with finite element (FE) simulations, revealed prestress levels in the range 25 % to 82 % of the reinforcement steel yield strength, depending on the section tested. A comparison with theoretically calculated residual prestress forces, taking into account friction and timedependent losses, indicated values of the same order but with some inconsistencies.

  • 12.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Nilimaa, jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    In-situ methods to determine residual prestress forces in concrete bridges2017In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 135, 41-52 p.Article in journal (Refereed)
    Abstract [en]

    Levels of residual prestress forces are key parameters when assessing the structural behaviour of existing prestressed concrete bridges. However, these parameters are often unknown and not easy to determine. To explore them, two existing non-destructive and destructive approaches have been further developed for practical application and demonstrated on a multi-span continuous girder bridge. The evaluation of the prestress forces was part of an extensive experimental programme aimed to calibrate and develop assessment methods. Due to the pursuit of practical applications for existing bridges, the main focus was on non-destructive methodology, combining experimental data and finite element modelling to obtain the residual prestress forces. Assuming that the initial prestress force corresponded to 85% of the characteristic 0.2% proof strength of the reinforcing steel, estimated losses in investigated sections ranged between 5 and 70%. However, determined residual prestress forces were generally higher than theoretically based estimates accounting for friction and time-dependent losses in the prestressing system. In addition to describing in detail the methods for prestress evaluation, this paper presents suggestions for improvements and further studies, based on experiences from the field tests.

  • 13.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Enochsson, Ola
    Sabourova, Natalia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Grip, Niklas
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Emborg, Mats
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Lundmark, Tore
    Ramböll Sverige AB, Luleå.
    Tu, Yongming
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Protecting a five span prestressed bridge against ground deformations2015In: IABSE Conference Geneva 2015: Structural Engineering: Providing Solutions to Global Challenges, Geneva: International Association for Bridge and Structural Engineering, 2015, 255-262 p.Conference paper (Other academic)
    Abstract [en]

    A 55 year-old, 121.5 m long, five span prestressed bridge was situated in the deformation zone close to a mine in Kiruna in northern Sweden. There was a risk for uneven ground deformations so the bridge was analyzed and monitored. Results and measures taken to ascertain the robustness of the bridge are presented.The analysis resulted in an estimate that the bridge could sustain 24 mm in uneven horizontal and 83 mm in uneven vertical displacement of the two supports of a span. To be able to sustain larger deformations, the columns of the bridge were provided with joints, where shims could be inserted to counteract the settlements. To accomplish this, each one of the 18 columns of the bridge was unloaded by help of provisional steel supports. The column was then cut and a new foot was mounted to it. This made it possible to lift each individual column with two jacks, when needed, and to adjust its height by inserting or taking away shim plates.The deformations of the bridge and the surrounding ground were monitored. The eigenmodes of the bridge were studied with accelerometers and by analysis with finite elements (FE) models. Comparison indicated good agreement between the model and the actual bridge, with calculated eigenfrequencies of 2.17, 4.15 and 4.67 Hz, for the first transversal, vertical and torsional modes, respectively. Measurements during winter resulted in higher values due to increased stiffness caused by frozen materials.

  • 14.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Puurula, Arto
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Carolin, Anders
    Trafikverket, Luleå.
    Full-Scale Tests to Failure Compared to Assessments: Three Concrete Bridges2017In: High Tech Concrete: Where Technology and Engineering Meet - Proceedings of the 2017 fib Symposium / [ed] Lukovic M.,Hordijk D.A., Cham: Springer, 2017, 1917-1924 p.Conference paper (Refereed)
    Abstract [en]

    Three Swedish concrete bridges have been tested to failure and the results have been compared to assessment using standard code models and advanced numerical methods.

    The three tested and assessed bridges were:

    1. (1)

      Lautajokk, a 29 year old one span (7 m) concrete trough bridge tested in fatigue to check the concrete shear capacity.

       
    2. (2)

      Ӧrnskldsvik, a 50 year old two span trough bridge (12 + 12 m) strengthened to avoid a bending failure.

       
    3. (3)

      Kiruna Mine Bridge, a 55 year old five span prestressed concrete road bridge (18 + 21 + 23 + 24 + 20 m) tested in shear and bending of the beams and punching of the slab.

       

    The main results in the paper are the experiences of the real failure types, the robustness/weakness of the bridges, and the accuracy of different codes and models. In all three cases the bridges had a considerable hidden capacity.

  • 15.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Tu, Yongming
    College of Civil Engineering, Southeast University, Nanjing.
    Carolin, Anders
    Trafikverket.
    Loading to failure of a 55 year old prestressed concrete bridge2015In: IABSE Workshop Helsinki 2015: Safety, Robustness and Condition Assessments of Structures, Zurich: International Association for Bridge and Structural Engineering, 2015, 130-137 p.Conference paper (Refereed)
    Abstract [en]

    In order to provide relevant data for calibration and development of methods for assessment ofexisting bridges, a 55 year old posttensioned concrete bridge has been subjected to non-destructiveand destructive tests. The bridge, located in Kiruna, Sweden, was a 121 m long girder bridgecontinuous in five spans. The test programme included failure loading of the girders and slab,respectively, condition assessment of the post-tensioned cables and material tests. Moreover, twostrengthening systems, using carbon fibre reinforcing polymer (CFRP), were evaluated. In this paperthe experimental programme and some preliminary results are presented to give an insight to researchproject.

  • 16.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    O'Connor, Alan
    Department of Civil, Structural and Environmental Engineering, Trinity College Dublin.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Pedersen, Claus
    Department of Bridges, Rambøll Danmark A/S.
    Moment redistribution in RC beams: A study of the influence of longitudinal and transverse reinforcement ratios and concrete strength2014In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 80, 11-23 p.Article in journal (Refereed)
    Abstract [en]

    In this paper, the results from an experimental programme, aimed at investigating moment redistribution in statically indeterminate reinforced concrete structures, are presented and compared with theoretical analysis of the structural behaviour. Due to the nonlinear structural behaviour of reinforced concrete structures, linear elastic analysis can lead to an inaccurate assessment of the behaviour and, therefore, it can become necessary to use more advanced methodologies to achieve sufficiently accurate analysis. Furthermore, more advanced methods can enable a higher degree of performance optimisation of structures than those resulting from the simplified approaches adopted by existing design codes based on linear elastic analysis with redistribution of internal forces. In order to assess the load-carrying capacity at the ultimate limit state (ULS), a model combining plastic and nonlinear analysis is presented. The evolution of moment redistribution to structural collapse was studied experimentally for continuous two-span beams. The focus of the experiments was on the influence of the longitudinal tensile reinforcement ratio at the intermediate support, the transverse reinforcement ratio and the concrete strength. The experimental response at the ULS was further compared with the predicted distribution of internal forces according to the theoretical model. Evaluation of the experimental study indicated a highly nonlinear structural behaviour of the tested beams with the distribution of moment differing from linear elastic analysis, even for low load levels. The evolution of moment redistribution and the moment redistribution at the ULS were appreciably dependent on the arrangement of longitudinal reinforcement, whilst the transverse reinforcement ratio had a marginal impact up to yielding of the longitudinal reinforcing steel, with the concrete strength slightly reducing the degree of moment redistribution. For those beams which failed in flexure, predictions from the theoretical model presented were in good agreement with the experimental results. However, several beams collapsed in shear-related failure modes.

  • 17.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Popescu, Cosmin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Failure tests on concrete bridges: Have we learnt the lessons?2017In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980Article in journal (Refereed)
    Abstract [en]

    Full-scale failure tests of bridges are important for improving understanding of bridges’ behaviour and refining assessment methods. However, such experiments are challenging, often expensive, and thus rare. This paper provides a review of failure tests on concrete bridges, focusing on lessons from them. In total, 40 tests to failure of 30 bridges have been identified. These include various types of bridges, with reinforced concrete or prestressed concrete superstructures, composed of slabs, girders and combinations thereof. Generally, the tests indicated that theoretical calculations of the load-carrying capacity based on methods traditionally used for design and assessment provide conservative estimates. It can also be concluded that almost a third of the experiments resulted in unexpected types of failures, mainly shear instead of flexure. In addition, differences between theoretical and tested capacities are often apparently due to inaccurate representation of geometry, boundary conditions and materials

  • 18.
    Bagge, Niklas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Shu, Jiangpeng
    Chalmers University of Technology.
    Plos, Mario
    Chalmers University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Punching Capacity of a Reinforced Concrete Bridge Deck Slab Loaded to Failure2015Conference paper (Other academic)
    Abstract [en]

    Full-scale failure tests of a 55 year old prestressed concrete girder bridge have been carried out to calibrate models for assessment of existing bridges. This paper summarises the outcome from the punching test and analytical analysis according to the model stated in the Eurocode. The experimental load was approximately 2.4 times the code value using measured material properties.

  • 19. Bennitz, Anders
    et al.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Olofsson, Thomas
    Kronborg, A.
    Wahlberg, A.
    Dynamic behaviour of the Vindel River railway bridge2006In: Condition Monitoring and Diagnostic Engineering Management: COMADEM 2006: proceedings / [ed] Uday Kumar; Aditya Parida; Raj B. K. N. Rao, Luleå: Luleå tekniska universitet, 2006, 721-729 p.Conference paper (Refereed)
    Abstract [en]

    The Swedish Railway administration has launched several projects aimed at increasing the accessibility of the railway lines in northern Sweden to meet future demands. One of these lines connects the southern and northern parts of Sweden and constitutes one of the major arteries for the transportation of heavy goods. Major investment are planned to upgrade the load bearing capacity of this railway line. The work is mainly focused on the larger structures and their dynamical properties. These properties can be used to assess existing infrastructure and to evaluate the performance. Advantages are obvious since the existing structural integrity form the base for investments in structural repair and upgrade of bridges. The Vindel River Railway Bridge situated 55 kilometers northwest of Umeå came into focus when large motion was discovered during train passages. The behaviour of the bridge crossing the river of Vindeln has been measured two times. Measurements of displacements and acceleration of the bridge during train passages has been conducted, the first measurements was done to give more experience on the motion of the bridge and to try out new sensors. The second measurement gave more information about the bridge's motion, results that could be used to calibrate a 3D FE-Model of the bridge used in the study. Based on the measurements, eigenfrequencies in the range of 0 to 8 Hz could be detected, modal shapes up to the ninth order could be extracted, deflections and transverse displacements for different sets of train and different train speeds were also found. However, new measurements are planned for this summer and will hopefully reinforce the already attained result and give answers to some of the unresolved questions.

  • 20.
    Bernander, Stig
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Dury, Robin
    Luleå tekniska universitet.
    Laue, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Progressive Landslide Analysis in Canadian Glacial Silty Clay in Churchill River2017In: / [ed] Vikas Thakur, Jean-Sébastien L’Heureux, Ariane Locat, 2017, 1- p.Conference paper (Other academic)
    Abstract [en]

    The poster presents the risks for a progressive landslide in a natural dam. The stability will be critical when the water level is raised after the building of a hydro power plant, Bernander (2016), Dury (2017). The analysis is based on a finite difference method developed by Stig Bernander (2011), Bernander et al.(2016)

     

    The following issues will be discussed:  

    - Material properties

    - Risk for liquefaction

    - Three possible failure surfaces: one horizontal, one inclined and one curved

    - Failure riska for different material propeties

    - The need to check the real properties of the soil

  • 21.
    Bernander, Stig
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Riverbank stability in loose layered silty clays: Comments on the North Spur Dam at Muskrat Falls in Churchill River, Labrador, Newfoundland2017Report (Refereed)
    Abstract [en]

    The differences are outlined in landslide analysis between the classic limit equilibrium method with assumed plastic properties of the soil and a progressive analysis applying softening material properties.

    The risk for failure is studied in the dam at the North Spur riverbank ridge at Muskrat Falls in Churchill River in Labrador, Newfoundland, Canada. A sloping failure surface is much more critical than the horizontal surfaces which have hitherto been studied. Results from new analyses have now been obtained applying softening material properties probable for the ridge. The results indicate safety factors lower than 0.5, i.e. there is a high risk that the ridge will fail if the water level is raised to the proposed level.

    Three reports are appended where Stig Bernander argues in detail for the need for a proper progressive failure analysis based on measured material properties. He also proposes how such properties may be obtained and gives an example of a way to stabilize the ridge if the soil properties show a softening behaviour. Finally examples of progressive failure analyses are included using probable material properties.

  • 22.
    Bernander, Stig
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Kullingsjö, Anders
    Skanska Teknik, Göteborg, Chalmers University of Technology.
    Gylland, Anders K
    Multiconsult, Norwegian University of Science and Technology (NTNU), Trondheim.
    Bengtsson, Per-Evert
    Statens Geotekniska Institut, Linköping, PEB Geoteknik.
    Pusch, Roland
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Olofsson, Jan
    Skanska Sverige AB, Skanska Teknik, Göteborg.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Downhill Progressive Landslides in Long Natural Slopes: Triggering Agents and Landslide Phases modeled with a Finite Difference Method2016In: Canadian geotechnical journal (Print), ISSN 0008-3674, E-ISSN 1208-6010, Vol. 53, no 10, 1565-1582 p.Article in journal (Refereed)
    Abstract [en]

    A large landslide in Tuve (Gothenburg, Sweden 1977) initiated the development of a model for slope stability analysis taking the deformation-softening of soft sensitive clays into consideration. The model studies triggering agents and five phases in progressive slope failure are identified: (1) in-situ, (2) disturbance, (3) unstable ‘dynamic’, (4) transitory (or permanent) equilibrium, and (5) ‘global’ failure. The clay resistance in these phases may differ widely; mostly due to different rates of loading. Two time dependent failure criteria are defined: (i) the triggering load condition in the disturbance Phase (2), and (ii) the transitory equilibrium in Phase (4), indicating whether minor downhill displacements or a veritable landslide catastrophe will occur. The analysis explains why downhill landslides tend to spread over vast areas of almost horizontal ground further down-slope. The model has been applied to landslides in Scandinavia and Canada. Three case studies are briefly discussed. The model is a finite difference approach, where local downhill deformations caused by normal forces is maintained compatible with deviatory shear deformations above the potential (or the established) failure surface. Software and an easy-to-use spreadsheet are introduced as well as recent developments. See also Video Abstract.

  • 23.
    Bien, Jan
    et al.
    Wroclaw University of Technology.
    Elfgren, LennartLuleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.Olofsson, JanSkanska.
    Sustainable bridges: assessment for future traffic demands and longer lives2007Collection (editor) (Other academic)
  • 24.
    Bischoff, Reinhard
    et al.
    EMPA, Swiss Federal Laboratory for Materials, Testing and Research.
    Meyer, Jonas
    EMPA, Zurich.
    Enochsson, Ola
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Feltrin, Glauco
    EMPA, Zurich.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Event-based strain monitoring on a railway bridge with a wireless sensor network2009In: Structural Health Monitoring of Intelligent Infrastructure: Proceedings of the 4th International Conference on Structural Health Monitoring of Intellgent Infrastructure / [ed] Urs Meier; Bernadette Havranek; Masoud Motavalli, Zürich: EMPA-Akademie , 2009, 74- p.Conference paper (Refereed)
    Abstract [en]

    This paper presents a monitoring application with a wireless sensor network that was performed on a 95 years old riveted steel railway bridge. In order to perform an accurate assessment, strains were monitored on critical elements to catch the real loading during the passage of heavy freight trains. The wireless sensor network deployed on the bridge consisted of 8 nodes supplied with resistance strain gages and the root node connected to a solar energy rechargeable, battery powered base station. The monitoring system was operated in event-based mode to achieve an energy efficient operation to prolong the lifetime of the sensor network. The event detection was carried out with ultra low power MEMS acceleration sensors, which measured continuously the accelerations of the bridge and detected an approaching train. If this occurred, the sensor generated an interrupt that immediately switched on the strain gage's conditioning board and starts the measurement. Switching on the conditioning board shortly before starting the measurement, however, produces biased raw data because the strain gage was still heating up due to the current flow. Instead of eliminating the time-dependent bias by adding a dummy gage to the Wheatstone bridge, the bias was removed by post-processing the raw data. The paper demonstrates that this procedure provides sufficiently accurate input data for use in cycle counting based fatigue assessment of steel bridges.

  • 25.
    Blanksvärd, Thomas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Häggström, Jens
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Nilimaa, Jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sabourova, Natalia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Grip, Niklas
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Carolin, Anders
    Paulsson, Björn
    UIC, Trafikverket.
    Tu, Yongming
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Test to failure of a steel truss bridge: Calibration of assessment methods2014In: Bridge Maintenance, Safety, Management and Life Extension: proceedings of the Seventh International Conference of Bridge Maintenance, Safety and Management, 7-11 July 2014, Shanghai, China / [ed] Airong Chen; Dan M. Frangopol; Xin Ruan, London: CRC Press, Taylor & Francis Group , 2014, 1076-1081 p.Conference paper (Refereed)
    Abstract [en]

    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.

  • 26. Broms, Carl Erik
    et al.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Skruvförankringar i maskinfundament1983In: Byggmästaren, ISSN 0007-7550, Vol. 62, no 9, 25-28 p.Article in journal (Other (popular science, discussion, etc.))
  • 27.
    Broms, Carl Erik
    et al.
    Jacobson & Widmark AB.
    Johansson, Håkan E
    Rehnström, Arne
    Anchor bolts in reinforced concrete foundations: short time tests1980Report (Other academic)
  • 28.
    Carolin, Anders
    et al.
    Trafikverket, Luleå.
    Anderson, Robert
    Network Rail, London, United Kingdom.
    Heissenberger, Roman
    ÖBB, Wien, Austria.
    Hermosilla Carrasco, Carlos
    Acciona Technology, Madrid, Spain.
    Schewe, Britta
    Deutsche Bahn, Berlin, Germany.
    Nilimaa, jonny
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Cwircen, Andrzej
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Innovative Intelligent Management of Railway Bridges, In2Rail: A European Horizon 2020 Project2016In: IABSE CONGRESS, STOCKHOLM, 2016: Challenges in Design and Construction of an Innovativeand Sustainable Built Environment / [ed] Lennart Elfgren, Johan Jonsson, Mats Karlsson, Lahja Rydberg-Forssbeck and Britt Sigfrid, CH - 8093 Zürich, Switzerland, 2016, 2552-2561 p.Conference paper (Refereed)
    Abstract [en]

    Innovative Intelligent Railways, In2Rail, is a European Horizon 2020 Project with the objective to enhance capacity, increase reliability and reduce Life Cycle Costs of European Railways. Bridges and Tunnels is the main focus in Work Package 4. The aim is to study, benchmark and further develop new Inspection Technologies in order to create more proactive maintenance procedures. In this paper some preliminary results are presented.

  • 29.
    Carolin, Anders
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Load-carrying capacity of concrete structures loaded in shear and torsion2002Report (Other academic)
    Abstract [en]

    The report is a state-of-the-art-report about load-carrying capacity in shear and torsion for concrete members.

  • 30. Carolin, Anders
    et al.
    Veljkovic, Milan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Vill vi betala mer för ökad dammsäkerhet?2007In: Norrbottens-Kuriren, 3- p.Article in journal (Other (popular science, discussion, etc.))
  • 31.
    Cederwall, Krister
    et al.
    Chalmers University of Technology.
    Edlund, Bo L.O.
    Chalmers University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Hjalmar Granholm: Legendarisk V-professor på Chalmers 1939-19651998Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    En kortfattad beskrivning av Hjalmers Granholms insatser som professor i byggnadsteknik på Chalmers tekniska högskola. Han föddes 1900 i Innertavle i Ume landsförsamling och dog 1972 i Göteborg

  • 32.
    Cederwall, Krister
    et al.
    Chalmers University of Technology.
    Elfgren, Lennart
    Losberg, Anders
    Chalmers University of Technology.
    Prestressed concrete columns under long-time loading1970Conference paper (Refereed)
  • 33. Cermona, Christian
    et al.
    Bien, Jan
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Field testing of old bridges2007In: Sustainable bridges: assessment for future traffic demands and longer lives / [ed] Jan Bien; Lennart Elfgren; Jan Olofsson, Wrocław: Dolnoslaskie Wydawnictwo Edukacyjne , 2007, 423-433 p.Conference paper (Refereed)
  • 34.
    Daerga, Per-Anders
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Draghållfasthet hos högpresterande betong1991In: Bygg & Teknik, ISSN 0281-658X, no 7, 25-26, 28 p.Article in journal (Other (popular science, discussion, etc.))
  • 35.
    Daerga, Per-Anders
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Ohlsson, Ulf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Behaviour of concrete at low temperatures1989In: POAC '89: 10th International conference on port and ocean engineering under arctic conditions / [ed] Kenneth B.E. Axelsson; Lennart Å. Fransson, Luleå: Luleå tekniska universitet, 1989, Vol. 2, 808-819 p.Conference paper (Other academic)
  • 36. Danielsson, Georg
    et al.
    Johansson, Håkan
    Thun, Håkan
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Töjningsmätning på järnvägsbro över Luossajokk i Kiruna2002Report (Other academic)
  • 37.
    Ditrani, Marco
    et al.
    Politecnico di Milano.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Eriksen, Jörgen
    Enochsson, Ola
    Veljkovic, Milan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Andersson, P.
    Vägverket.
    Eriksson, Per
    Vägverket.
    Improving transportation investment decision through life-cycle cost analysis: case study on some bridges in the north of Sweden2009In: Sustainability of Constructions - Integrated Approach to Life-time Structural Engineering: Proceedings of the Workshop Timişoara, 23-24 October 2009. COST Action C25, 2009, 266-275 p.Conference paper (Refereed)
    Abstract [en]

    The scope of this project is to perform Life Cycle Cost Analysis (LCCA) on different types of bridges, in order to learn which is most cost-efficient in a particular situation. A second scope is to study the impact of different cost items on the whole Life Cycle Cost. The work is performed to enable optimal strategic decisions regarding future investments.Beam and Slab Bridges, Slab Bridges and Slab Frame Bridges are analyzed. The bridges are located in the north of Sweden, in the regions of Norrbotten and Västerbotten. All bridges have a total length of around 20 m, which is the most common length in Sweden and in Europe. Furthermore, the analysis includes Timber and Soil-Steel bridges in order to understand the prospects for this types of bridges in Sweden. The analysis does not focus on a particular bridge but, based on information from some Swedish producers, it studies different scenarios.The data collection covers initial investments, maintenance, repair and rehabilitation (MR&R) costs, user and demolition costs.

  • 38. Dury, Robin
    et al.
    Bernander, Stig
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Kullingsjö, Anders
    Skanska Teknik AB.
    Laue, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Pusch, Roland
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Progressive Landslide Analysis with Bernander Finite Difference Method2017In: / [ed] Vikas Thakur, Jean-Sébastien L’Heureux, Ariane Locat, 2017, 1- p.Conference paper (Other academic)
    Abstract [en]

    The poster presents a new Spreadsheet developed by Robin Dury (2017) to simplify the use of the Finite Difference Method developed by Stig Bernander et al (2011, 2016).

    It includes:

    - Material Properties

    - Finite Difference Method

    - Progressive failure process with five phses

    - Discussion

    - References

  • 39.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Activity: Bridge Design, K7005B2015Conference paper (Other (popular science, discussion, etc.))
  • 40.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Aktivitet: Högpresterande betong ger lättare konstruktioner1992Other (Other (popular science, discussion, etc.))
  • 41.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Aktivitet: Kompetenscentra behövs. Goda erfarenheter av tvärdisciplinär forskning i Luleå1992Other (Other (popular science, discussion, etc.))
  • 42.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    American Structural Engineering Research: A report form an academic year in the United States and Canada 1972-731975Report (Other (popular science, discussion, etc.))
  • 43.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Analogy between anchor bolt failure and punching shear2000In: Proceedings: International Workshop on Punching Shear Capacity of RC Slabs, dedicated to professor Sven Kinnunen / [ed] J. Silfwerbrand; G. Hassanzadeh, Stockholm: Kungl Tekniska Högskolan Institutionen för Byggkonstruktion , 2000, 493-502 p.Conference paper (Refereed)
    Abstract [en]

    Similarities in the behaviour, analysis and design of anchor bolts and punching shear are discussed. The treatment of size effects in codes is compared.

  • 44.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Arne Hillerborg and Fracture Mechanics1991In: Analysis of Concrete Structures by Fracture Mechanics: Proceedings of the International RILEM Workshop dedicated to pofessor Arne Hillerborg / [ed] Lennart Elfgren; Surendra P Shah, London: Taylor and Francis Group , 1991, 1-16 p.Conference paper (Refereed)
    Abstract [en]

    The paper gives an overview of Arne Hillerborg's contributions to Fracture Mechanics. Arne Hillerborg was born in 1923 and was a professor at Lund Institute of Technology 1968-1989.

  • 45.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Assessment of structural concrete: results from a European research project Sustainable Bridges2008In: Proceedings, Nordic Concrete Research, Bålsta, Sweden: [ ... XXth Symposium on Nordic Concrete Research & Development ... The current proceedings contain 90 summaries of oral poster presentations] / [ed] Johan Silfwerbrand, Oslo: Norsk Betongforening , 2008, 140-141 p.Conference paper (Refereed)
  • 46.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Avancerade cementbaserade material och konstruktioner1994In: Bygga framtid, Vol. 5, 72, 74-76 p.Article in journal (Other (popular science, discussion, etc.))
  • 47.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Avdelningen för Konstruktionsteknik. Verksamhetsberättelse 1983/841984Report (Other (popular science, discussion, etc.))
  • 48.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Avdelningen för Konstruktionsteknik. Verksamhetsberättelse 1984/851985Report (Other (popular science, discussion, etc.))
  • 49.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Benchmark of new technologies to extend the life of elderly rail infrastructure: Deliverable D1.1 of the MAINLINE Project2013Report (Refereed)
    Abstract [en]

    There are many traditional technologies available to extend the life of elderly rail infrastructure, some of which are being improved or developed, whilst new technologies continue to emerge. In this report an overview is given of some of the most promising new or updated technologies. Based on these findings further work in the Mainline project will mostly focus on the following areas: - Assessment methods - Monitoring methods- Repair and Strengthening methodsQuestionnaires on bridges, tunnels, earthworks and track were prepared and twelve Infrastructure Managers have responded to the bridge questionnaire; responses to the other questionnaires have been more limited. If the results from this bridge sample are extrapolated from the about 125 000 km of network and the about 150 000 railway bridges that these Infrastructure Managers oversee to the full European network, which is about 230 000 km, a rough estimate may be obtained of the needs for the next years. Such an extrapolation suggests that in the next ten years we may expect to strengthen some 1 500 bridges, to replace some 4 500 bridges and to replace the deck of some 3 000 bridges. Some of the bridges that are planned to be replaced may instead be strengthened, if the new technologies presented here would be used.Work is also going on to improve the life length of track, switches and crossings and other rail infrastructure as earthwork, tunnels, drainage and culverts.It can also be seen that not many Infrastructure Managers currently use Life Cycle Costing (i.e. financial) and/or Life Cycle Assessment (i.e. environmental) in the planning of maintenance and repair of their rail infrastructure. There is a lack of data and methods and here the Mainline Project is intending to give guidance. There is also often a lack of economic resources for maintenance which may lead to a shorter life length and less sustainability than would otherwise be the case; results from the Mainline Project are also intended to give advice that may help to improve this situation.Stakeholders in Europe will benefit from reduced costs, higher efficiency and reduced environmental impact for existing rail infrastructure by using the methods presented here. For upgrading of bridges some 150 million Euros per year may be saved compared to the cost of replacing existing bridges with new ones. For track and other rail infrastructure similar savings may be achieved adding up to a total possible saving of more than 300 million euros per year. In Eastern Europe savings may be proportionally larger as a larger part of the tracks and the structures is old and in need of upgrading or replacement.

  • 50.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Betongforskning vid Luleå tekniska universitet2001In: Betong, ISSN 1101-9190, Vol. 11, no 3, 19-21 p.Article in journal (Other (popular science, discussion, etc.))
1234567 1 - 50 of 301
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