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  • 1.
    Abed El-Fattah Safi, Mohammed
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Bridge Life Cycle Cost Optimization: Analysis, Evaluation, & Implementation2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 2.
    Almaleh, Nabaz
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Djuric, Milan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Utformning av lådbalkbroar i högpresterande betong med extern förspänning2005Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 3. Alsafadie, Rabe
    et al.
    Hjiaj, Mohammed
    Structural Engineering Research Group/LGCGM, INSA de Rennes, France.
    Battini, Jean-Marc
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Corotational mixed three-dimensional finite element for structural stability problems2010In: ECCM 2010, IV European Conference on Computational Mechanics, 2010Conference paper (Refereed)
    Abstract [en]

    The corotational technique exploits the technology that applies to a two–noded element a coordinatesystem which continuously translates and rotates with the element. In this way, the rigid bodymotion is separated out from the deformational motion. In this paper, a mixed formulation is adoptedfor the derivation of the local element tangent stiffness matrix and nodal forces. The mixed finiteelement formulation is based on the two–field Hellinger–Reissner variational principle. This localelement, together with the corotational framework, can be used to analyze the nonlinear bucklingand postbuckling of thin–walled beams with arbitrary cross–section. The mixed formulation solutionis compared against the results obtained from a corotational displacement–based formulation havingthe same beam kinematics. The superiority of the mixed formulation is clearly demonstrated.

  • 4.
    Andersson, Andreas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Capacity assessment of arch bridges with backfill: Case of the old Årsta railway bridge2011Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The work presented in this thesis comprises the assessment of existing arch bridges with overlying backfill. The main objective is to estimate the load carrying capacity in ultimate limit state analysis. A case study of the old Årsta railway bridge is presented, serving as both the initiation and a direct application of the present research. The demand from the bridge owner is to extend the service life of the bridge by 50 years and increase the allowable axle load from 22.5 to 25 metric tonnes. The performed analyses show a great scatter in estimated load carrying capacity, depending on a large number of parameters. One of the factors of main impact is the backfill material, which may result a significant increase in load carrying capacity due to the interaction with the arch barrel. Based on theoretical analyses, extensive conditional assessments and the demand from the bridge owner, it was decided that the bridge needed to be strengthened.

    The author, in close collaboration with both the bridge owner and the persons performing the conditional assessment, performed the development of a suitable strengthening. The analyses showed a pronounced three-dimensional behaviour, calling for a design using non-linear finite element methods. Due to demands on full operability during strengthening, a scheme was developed to attenuate any decrease in load carrying capacity. The strengthening was accepted by the bridge owner and is currently under construction. It is planned to be finalised in 2012.

    The application of field measurements to determine the structural manner of action under serviceability loads are presented and have shown to be successful. Measured strain of the arch barrel due to passing train has been performed, both before, during and after strengthening. The results serve as input for model calibration and verification of the developed strengthening methods.

    The interaction of the backfill was not readily verified on the studied bridge and the strengthening was based on the assumption that both the backfill and the spandrel walls contributed as dead weight only. The finite element models are benchmarked using available experimental results in the literature, comprising masonry arch bridges with backfill loaded until failure. Good agreement is generally found if accounting for full interaction with the backfill. Similarly, accounting for the backfill as dead weight only, often results in a decrease in load carrying capacity by a factor 2 to 3. Still, several factors show a high impact on the estimated load carrying capacity, of which many are difficult to accurately assess. This suggests a conservative approach, although partial interaction of the backfill may still increase the load carrying capacity significantly.

  • 5.
    Andersson, Andreas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Gamla Årstabron, FEM-beräkning av förstärkningsåtgärders inverkan på betongbågarna2006Report (Other academic)
  • 6.
    Andersson, Andreas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Gamla Årstabron, FEM-beräkningar av 3-ledsbågarnas verkningssätt och inverkan på förstärkningsåtgärder2007Report (Other academic)
    Abstract [sv]

    Denna rapport redovisar brottgränsberäkningar av gamla Årstabrons 3-ledsbågar. Beräkningarna är till stor del utförda med FEM och är gjorda på liknande sätt som tidigare rapport avseende nolledsbågarna.

  • 7.
    Andersson, Andreas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Gamla Årstabron, Sammanställning av beräkningar avseende förstärkningar av betongbågarna2007Report (Other academic)
  • 8.
    Andersson, Andreas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Utmattningsanalys av järnvägsbroar: En fallstudie av stålbroarna mellan Stockholm Central och Söder Mälarstrand, baserat på teoretiska analyser och töjningsmätningar2009Licentiate thesis, monograph (Other academic)
    Abstract [en]

    The present thesis comprises a case study of the risk of fatigue of the railway bridges chaining between Stockholm Central Station and the district Söder Mälarstrand. A large number of fatigue-related cracks in the bridges at Söderström and Söder Mälarstrand have been known for a long time. During a capacity assessment of the current bridges, a large number of connections have been identified as critical concerning fatigue resistance. The route is the most frequent in all of Sweden and the simplified methods of fatigue assessment defined by Banverket may not always be applicable.

    A conventional capacity assessment has shown numerous exceeds in fatigue resistance, using the stated safety margins. No fatigue cracks have been identified at the locations showing the largest theoretical risk of fatigue, in spite of extensive investigations. The conventional calculations are based on a uniform stress collective and a fixed number of stress cycles, independent of the actual traffic volume. According to the regulations stated by Banverket, the assessment may optionally be performed using historical data of the gross tonnage and standardised traffic loading. Such calculations have been undertaken and show even greater risk of fatigue, compared to the conventional assessment. To estimate the risk of fatigue in more detail, a method has been used, based on estimations of the real traffic volume and its distributions. The analysis is based on available data of the traffic volume and may be applied to other railway bridges on other locations.

    Besides theoretical analyses, field measurements have been performed. In 2006, former Carl Bro AB carried out strain gauge measurements on the bridge passing Söder Mälarstrand and the viaduct south of Söder Mälarstrand. The measurements comprised a small amount of individual train passages. During 2008, the division of Structural Design and Bridges at KTH performed an extensive field measurement programme on the bridge passing Söderström. Continuous measurements collecting data of all traffic during a period of one month was performed.

  • 9.
    Andersson, Andreas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Carlsson, Fredrik
    Lunds Tekniska Höskola.
    Enckell, Merit
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Enochsson, Ola
    Luleå Tekniska Universitet.
    Karoumi (Redaktör), Raid
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Malm, Richard
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Plos, Mario
    Chalmers Tekniska Högskola.
    Sundquist, Håkan
    KTH, School of Architecture and the Built Environment (ABE).
    Täljsten, Björn
    LuleåTekniska Universitet.
    Wiberg, Johan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Ülker, Mahir
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Modern mät- och övervakningsmetodik för bedömning av befintliga broar2007Report (Other academic)
  • 10.
    Andersson, Andreas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Sundquist, Håkan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Gamla Årstabron, Utvärdering av verkningssätt hos betongvalv genom mätning och FEM-modellering – Etapp 12005Report (Other academic)
  • 11.
    Andersson, Andreas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Sundquist, Håkan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Utvärdering av krafter i Älvsborgsbron genom dynamisk mätning och analys2006Report (Other academic)
    Abstract [sv]

    Föreliggande rapport behandlar mätning och analys av krafter i Älvsborgsbron i Göteborgsom underlag för klassningsberäkning. Den metod som används för bestämning av krafternaär den s.k. vibrationsmetoden där konstruktionselement sätts i svängning och dessas egenfrekvenserbestäms med hjälp av accelerometrar. Med kända egenfrekvenser för t.ex. kablaroch hängare kan krafterna i dessa analyseras fram. Eftersom flera av de aktuella elementenhar egenskaper som inte är enkla att beskriva med hjälp av faktorer som geometriska mått,massa, styvhet och inspänningsförhållanden, har möda lagts ner på att använda så noggrannametoder som möjligt för att kunna bestämma krafter och kraftfördelning. Metoderna beskrivsi rapporten och resultat och noggrannhet diskuteras och bedöms.De resultat som presenteras beträffande krafter bedöms ha en så god noggrannhet som det f.n.går att analysera fram med idag kända någorlunda enkla metoder.

  • 12.
    Andersson, Andreas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Sundquist, Håkan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Karoumi, Raid
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Evaluating cable forces in cable supported bridges using ambient vibration method2006In: The International Conference on Bridge Engineering – Challenges in the 21st Century , November 1-3, 2006, Hong Kong, Hong Kong, 2006Conference paper (Other academic)
    Abstract [en]

    This paper deals with the assessment of cable forces in existing cable supported bridges using the ambient vibration method. A case study of the Älvsborg suspension bridge in Sweden is presented. Dynamic measurements of the backstays and hangers as well as on each strand in one of the splay chambers have been carried out. The measured frequencies are evaluated and calculations of corresponding axial force in the cable structures are performed taking into account the cable sag, boundary conditions and flexural rigidity. Modal analyses have been used to study the shape of vibration and for comparison with finite element models.

  • 13.
    Ansell, Anders
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Pettersson, Tage
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Sundquist, Håkan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Envånings pelare och plana pelarsystem2006Report (Other academic)
  • 14.
    Ansell, Anders
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Silfwerbrand, Johan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    The vibration resistance of young and early age concrete2003In: Structural Concrete, ISSN 1464-4177, Vol. 4, 125-134 p.Article in journal (Refereed)
    Abstract [en]

    During early age, concrete is vulnerable to disturbance from vibrations of large magnitudes. Today, conservative vibration limits are used as standards, and guidelines provide little information. The literature cited in this study contains experiences and results from the construction and civil engineering field, in-situ testing, laboratory testing and computer modelling. On the basis of the reviewed literature, recommended maximum vibration levels for young and early-age concrete are given.

  • 15.
    Ansell, Anders
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Silfwerbrand, Johan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Sundquist, Håkan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Krympning, pågjutningar och samverkan hos betongkonstruktioner2006Report (Other academic)
  • 16.
    Anund, Jonas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Känslighetsanalys vid kostnadskalkylering2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 17.
    Arvidsson, Therese
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Li, Jiajia
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Dynamic analysis of a portal frame railway bridge using frequency dependent soil structure interaction2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With the development of high-speed railroads the dynamic behaviour of railroad bridges is increasingly important to explore. Deeper knowledge about the influence of different factors and what should be included in a model is essential if the designer shall be able to make reliable estimates of responses in existing and new structures. One factor is the soil-structure interaction (SSI), describing how the foundation of the bridge and the soil properties affect the behavior of the bridge under dynamic loading.

    In this thesis, the influence of including SSI in a model of a portal frame railway bridge is studied, and an analysis procedure in the frequency domain for models with frequency-dependent boundary conditions is described. A 3D finite element model of an e isting bridge has been built up, based on the theory of linear elasticity. The model has been given three different types of boundary conditions: clamped, static stiffness and frequency-dependent stiffness from SSI. Results from simulated train passages, with a train set consisting of two wagons, were compared for the different boundary conditions. The models have also been compared with measurement data from the bridge, which has given indications about which model describes reality in the best way.

    The results show that the model in which SSI is included by frequency dependent boundary conditions is in slightly better agreement with measurement data than the clamped model and the model with static stiffness. The model gives a slightly better damping of the free vibrations and the natural frequencies correspond better with experimental data. The difference in maximum acceleration from a train passage is very small between the different models, even if it is found that the clamped model generally has lower accelerations and hence is non-conservative. It appears that the train speed affects the maximum acceleration, the size of the free vibrations and the natural frequencies that are present in the free vibrations in the models.

    Further studies are suggested where it is emphasized that an analysis with longer trains, which give resonance phenomena, should be made to see how the different eigenfrequencies in the models affect the accelerations at different speeds. It is also noted that more measurements would be needed in order to draw more general conclusions about the degree of correspondence between the measurements and the models, and to calibrate the parameters of the model against measurement data.

  • 18.
    Aziz, Ari
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Parametrisk studie av vippningsavstyvande stålbalksbjälklag utförda med I-profiler2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 19.
    Baravalle, Michele
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Nationally Determined Parameters of Eurocode 2: A Comparison among Seven European Countries2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Since the main ambition of the European community is to create a Single Market among the European countries, a unified set of structural design codes recently became mandatory to use. These standards, the Eurocodes, contain Nationally Determined Parameters (NDPs) that have to be fixed by the National Standard Bodies in the various countries.

    The investigation of the adopted values for Eurocode 2 in seven European States has been carried out i  this thesis for quantifying the differences that arise from the selected values of these parameters. The aim of this investigation was to find out which countries are advantaged or disadvantaged by the choice of the value of these parameters. The analysis has been limited to the Part 1-1 of Eurocode 2 that concerns “General Rules for Buildingsand the most important parts of Eurocode 0 and 1. The investigated countries were Denmark, Finland, France, Germany, Italy, Sweden and the United Kingdom. Even if these countries represent only seven out of 27 EU States, this comparison gives a good view of the European situations since they cover nearly half of the continental concrete consumption. The analysis includes a theoretical comparison of the national choices of all the 170 national parameters as well as their influence on the more important formulas contained in the Code. Five practical case studies concerning the design and the verification of some structural elements have been carried out in order to study the differences in real and common design situations. Through all the work, the different choices have been compared to the recommended values proposed by the Eurocode that have been used as a mean of comparison.

    Due to the large number of parameters and the complexity of the problem it has not been possible to estimate and quantify general trends of differences for the countries although Finland, France, Italy and the United Kingdom have been found to have, in general, more disadvantageous choices than the other States. Moreover, Denmark and Germany show variable trends (both above and below the recommended values) while Sweden is always close to the recommended values. The results that have been found show that still a lot of work and research has to be done in order to achieve an even set of structural standards for the design of concrete structures. A list of more important national parameters has been presented as well as a proposal to convert some national parameters to fixed ones. The analysis and the results that have been obtained give details and indications about the future works that need to be done for decreasing the differences among the European countries.

  • 20.
    Battini, Jean-Marc
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Ülker-Kaustell, Mahir
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    A simple finite element to consider the non-linear influence of the ballast on vibrations of railway bridges2011In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 33, no 9, 2597-2602 p.Article in journal (Refereed)
    Abstract [en]

    This article proposes a new and simple finite element which can be used to analyze vertical vibrations in railway bridges. The main feature of the element is that the effect of the ballast is introduced through a non-linear longitudinal stiffness associated to the slip at the interface between the bridge and the ballast. Two numerical applications show that this element can be used to model the variation of the natural frequencies of the bridge as a function of the amplitude of vibration.

  • 21.
    Bayoglu Flener, Esra
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Full-scale Testing of two Corrugated Steel Box Culverts with Different Crown Stiffness: Part I2006Report (Refereed)
  • 22.
    Bayoglu Flener, Esra
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Full-scale Testing of two Corrugated Steel Box Culverts with Different Crown Stiffness, Part II2007Report (Refereed)
  • 23.
    Bayoglu Flener, Esra
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Response of Long-Span Box Type Soil-Steel Composite Structures during Ultimate Loading Tests2009In: Journal of Bridge Engineering, ISSN 1084-0702, Vol. 14, no 6, 496-506 p.Article in journal (Refereed)
    Abstract [en]

    Soil-steel composite structures are getting more popular in recent years. With the introduction of more sophisticated structures such as box culverts with flexural stiffeners, the review of largely experience based design models became inevitable. The paper presents the ultimate loading part of full-scale testing conducted on corrugated steel box culverts. Structures with two different spans of 14 and 8 m and different crown stiffness were investigated using different cover depths. The tests indicate that the response of the structure to the depth of the cover is not linear. The structures become more vulnerable to applied loads as the soil cover decreases. The increase in the load-bearing capacity with increasing soil covers is linear, which agrees with the theoretical models. The crown stiffening, however, is more effective under shallow soil covers. The load resistance of the structures is doubled at the crown level with the crown stiffening. The Swedish design method overestimates live load moments but underestimates live load thrusts. An adjustment to the calculation of the thrusts is proposed. The Canadian design method estimates the moments relatively well but it does not cover larger spans than 8 m.

  • 24.
    Bayoglu Flener, Esra
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Soil-Steel Interaction of Long-Span Box Culverts-Performance during Backfilling2010In: Journal of Geotechnical and Geoenvironmental Engineering, ISSN 1090-0241, Vol. 136, no 6, 823-832 p.Article in journal (Refereed)
    Abstract [en]

    The paper presents the performance of four long-span deep-corrugated steel box culverts with spans of 8- and 14-m during backfilling, as well as comparisons with finite-element modeling and design codes. Two of the culverts were stiffened at the crown arch. The test results show that the stiffening applied on the culverts is quite effective. The crown rises of the respective stiffened culverts were found to be half those of the not-stiffened culverts. The influence of the structure geometry on the soil-passive earth pressure was confirmed, as well as the sensitivity of box culverts to soil loads with increasing spans. The results showed that the influence of the size and shape of the box culverts on the amount of thrusts must be better implemented in the design method. The finite-element analysis results were conservative when live loading was concerned but the crown displacements and thrust during backfilling were underestimated.

  • 25.
    Bayoglu Flener, Esra
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Static and dynamic behaviour of soil-steel composite bridges obtained by field testing2009Doctoral thesis, comprehensive summary (Other academic)
  • 26.
    Bayoglu Flener, Esra
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Testing the Response of Box-Type Soil-Steel Structures under Static Service Loads2010In: Journal of Bridge Engineering, ISSN 1084-0702, Vol. 15, no 1, 90-97 p.Article in journal (Refereed)
    Abstract [en]

    The paper presents the static loading of four long-span deep-corrugated steel box culverts with spans of 14 and 8 m. The tests, which were part of a series of full-scale tests, involved strain and displacement measurements carried out at different cover depths under the load of a truck. Two of the culverts were stiffened at the crown. The test results showed that the stiffening applied on the culverts is quite effective and that plain structure is more sensitive to cover depth compared to stiffened structure. The crown stiffening is more effective under shallow soil covers. The maximum displacement of plain structure is approximately twice the maximum displacement of the stiffened structure measured at 45-cm depth of cover. The Swedish and Canadian design methods are conservative when estimating live load moments but they underestimate live load thrusts. The measured maximum thrusts are up to four times larger than the calculated design values where the variation depends on the size of the culverts and the depth of soil. The culvert size has considerable influence on the thrusts and moments generated at the crown centerline, which could be implemented in the design models.

  • 27.
    Bayoglu Flener, Esra
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Karoumi, Raid
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Dynamic testing of a soil-steel composite railway bridge2009In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 31, no 12, 2803-2811 p.Article in journal (Refereed)
    Abstract [en]

    Actual dynamic response of a long-span corrugated steel culvert railway bridge is studied. The bridge, which is a type of soil-steel composite structures, has a span of 11 m. Tests were carried out by measuring strains and displacements during passages of a locomotive at different speeds. Vertical ballast accelerations as well as the effects of braking forces were also measured. The tests showed that the speed has a large influence on the displacements, thrusts and moments. The measured dynamic displacements and thrusts are as much as 20% larger than the corresponding static response. This is greater than the values specified in bridge design codes. Dynamic amplification factors as high as 1.45 were obtained for the moments at the quarter point which is found to be much larger than the values for the crown point. This type of bridge structure is believed to be less sensitive to resonance from passing trains than other common bridge types, due to the high damping values obtained from the forced vibration tests.

  • 28.
    Bayoglu Flener, Esra
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Karoumi, Raid
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Testing the static and dynamic behaviour of a soilsteel bridgeManuscript (preprint) (Other academic)
  • 29.
    Bayoglu Flener, Esra
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Karoumi, Raid
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Sundquist, Håkan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Field testing of a long-span arch steel culvert during backfilling and in service2005In: Structure and Infrastructure Engineering, ISSN 1573-2479, Vol. 1, no 3, 181-188 p.Article in journal (Refereed)
    Abstract [en]

    The paper presents the first part of the in-situ measurements and data analyses for the tests conducted during backfilling and during service of a long-span corrugated steel culvert railway bridge over Skivarpsan, Rydsgard, Sweden. Static and dynamic tests were carried out measuring strains and displacements. Temperature readings were taken along with the measurements. Comparisons of moments during compaction showed that there is good agreement between test results and theoretical values. The theoretical calculation of the rise of the crown during compaction and the crown moments due to live load seem to be conservative, while the theoretical axial forces agree reasonably with the measured axial forces.

  • 30.
    Bengts, Eric
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Jansson, Robert
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Modellering av gamla Lidingöbron2004Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    By order of the city of Lidingö has an examination being started to determine the current state of the old Lidingö bridge, citied just outside the city of Stockholm. The assignment went to Carlbro AB, Stockholm. They have engaged the department of structural engineering at the Royal Institute of Technology to perform measurements of the stresses during the crossing of trains. The measurements were made in the beginning of October 2003, [1]. This master thesis has been made in addition to these measurements in purpose to develop a finite element model of the bridge.

    The Lidingö bridge is mainly a truss bridge with in general 50 m spans with the exception of an arc span and a longer span of 70 m. The bridge has a total length of approximately 730 m. The Lidingö bridge began to be used in 1925. It was originally dimensioned for railroad-, tramway- and car traffic and bicycles and pedestrians. The traffic intensity on the bridge increased over the years when it served as the only permanent connection to the mainland. Over the years have many renovations and rebuildings been made, the latest in 1986. The traffic today is less than it once was with rails on one side and pedestrians and bicycles on the other, when it earlier was a double railroad. During the construction were there confusions between the different types of steel in the framework. Insufficient steel was used in constructive parts and several reparations have been made to correct this error. The bridge has to this day been used for nearly 80 years and is assumed to be in relatively bad condition. It has been exposed to a large amount of on- and off loadings with high stresses. The Lidingö bridge has filled an important function for the island and several examinations have earlier been made to ensure its state.

    The purpose of the examination is to determine the steels present condition and to present measures for its future use. As a base for the determination of the bridges future lies the stress measurements which has been made in choosed beams. Interesting is how high stresses and stress spans there is under to days load. The examination also involves future measurements under the coming winter. This master thesis aims primarily to develop a reliable finite element model of the bridge. The model is based on original- and renovation drawings and self made measurements from platforms. The drawings are located in the technical office and the city archive, both citied on Lidingö. The model has been refined with help from the measurements of the stresses. The bridge has a couple of hinges and joints which can have insufficient condition. In addition to that there is a simulation of how winter state effects the beams. The model is limited to the part starting from the end of the arc span and ends at the abutment on Lidingö, Figure 1.1.

    The results from the model have shown good correspondence to the strain measurements and an earlier examination done in 1967. A small difference appears on the pedestrian side. It could be explained with the fact that the superstructure stiffens the construction which leads to larger stresses on that side. With that in mind has the model been used to make further examinations of the Lidingö bridges condition. The made calculations in SOLVIA has not shown any stresses close to the steels yield point.

  • 31.
    Berggren, Patrik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Dimensioneringshjälp vid konstruktion av kolfiberförstärkning på enkelspänd bjälklagsplatta i ett fack2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 32.
    Bjurström, Henrik
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Lasell, Johan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Capacity assessment of a single span arch bridge with backfill: A case study of the Glomman Bridge2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 33.
    Björklund, Lena
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Dynamic Analysis of a Railway Bridge subjected to High Speed Trains2005Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 34.
    Boulenger, Maxime
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Life Cycle Assessment of concrete structures using public databases: Comparison of a fictitious bridge and tunnel2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Concrete structures represent a huge investment in terms of materials and energy and they lead to significant environmental impacts. Thus, there is a need to choose the most sustainable and eco-friendly alternative. From this perspective, this report aims to evaluate the environmental impacts associated with the construction of two fictitious structures: a bridge and a tunnel. To fully assess and fairly compare the environmental burdens of those two structures, the life cycle assessment (LCA) has been chosen. Prior to the case studies, the LCA process is described and a literature review related to LCAs of road structures is performed thus revealing the key facts and key figures of such studies.

    Based on this literature review, a simplified LCA is performed; it relies on public databases and only takes into account the construction phase. Because of data constraints, the indicators that are considered are NOx, SOand CO2 emissions, and the categories that are taken into account are energy consumption, global warming potential and photochemical oxidant formation. Characterization factors come from the REciPE method. Three different stages are considered and compared during this LCA study; the production of materials, the construction processes and the transportation phase.

    Results show that the environmental impacts of the bridge are higher than the ones of the tunnel and that the amount of concrete has a strong influence on the final results and consequently on the interpretation phase. This study also emphasizes the importance of assumptions and describes their potential influence on the final results by considering two different alternatives related to the concrete’s manufacturing. Making the concrete directly on site instead of bringing it by truck significantly decreases the environmental impacts of both structures; indeed, for the bridge structure, it leads to a diminution in CO2 emissions, global warming potential and energy consumption by more than 60%.

    The main constraint of this study has been the data collection for the life cycle inventory; indeed, many data were missing or coming from different public databases which result in a lack of thoroughness and precision (e.g. different geographical representativeness). Results of this study strongly depend on the various assumptions and on the data that have been collected, and technical choices, methodologies of construction or structural design mainly depend on the project’s location; consequently, results and conclusions cannot be generalized and should be handled carefully.

  • 35.
    Broms, Carl Erik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Concrete flat slabs and footings: Design method for punching and detailing for ductility2005Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Simple but still realistic physical models suitable for structural design of flat concrete plates and column footings with respect to punching are presented.

    Punching of a flat plate is assumed to occur when the concrete compression strain at the column edge due to the bending moment in the slab reaches a critical value that is considerably lower than the generally accepted ultimate compression strain 0.0035 for one-way structures loaded in bending. In compact slabs such as column footings the compression strength of the inclined strut from the load to the column is governing instead. Both the strain limit and the inclined stress limit display a size-effect, i.e. the limit values decrease with increasing depth of the compression zone in the slab. Due respect is also paid to increasing concrete brittleness with increasing compression strength.

    The influence of the bending moment means that flat plates with rectangular panels display a lower punching capacity than flat plates with square panels – a case that is not recognized by current design codes. As a consequence, punching shall be checked for each of the two reinforcement directions separately if the bending moments differ.

    Since the theory can predict the punching load as well as the ultimate deflection of test specimens with good precision, it can also treat the case where a bending moment, so called unbalanced moment, is transferred from the slab to the column. This opens up for a safer design than with the prevailing method. It is proposed that the column rotation in relation to the slab shall be checked instead of the unbalanced moment for both gravity loading and imposed story drift due to lateral loads.

    However, the risk for punching failure is a great disadvantage with flat plates. The failure is brittle and occurs without warning in the form of extensive concrete cracking and increased deflection. Punching at one column may even initiate punching at adjacent columns as well, which would cause progressive collapse of the total structure. A novel reinforcement concept is therefore presented that gives flat plates a very ductile behaviour, which eliminates the risk for punching failure. The performance is verified by tests with monotonic as well as cyclic loading.

  • 36.
    Broms, Carl Erik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Ductility reinforcement for flat slabs in seismic areas2006In: Magazine of Concrete Research, ISSN 0024-9831, Vol. 58, no 4, 243-254 p.Article in journal (Refereed)
    Abstract [en]

    The reinforcement concept `ductility reinforcement' has previously been shown to give fat slabs such extremely ductile behaviour that the punching failure mode for gravity loading can be considered safely eliminated. That concept is now tested for imposed cyclic storey drift during earthquakes and found to be capable of resisting even severe earthquakes without any additional precautions than those already taken for normal gravity loading. The specimens were loaded with gravity load up to about 75% of their flexural yield capacity in order to simulate the ultimate limit load case involving seismic loads. Design recommendations are given based on these findings, where assessment of transferred moment between slab and column as currently dictated by North American practice is not required.

  • 37.
    Broms, Carl Erik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Ductility Reinforcement for Flat Slabs in Seismic as well as Non-seismic Areas2005In: Magazine of Concrete Research, ISSN 0024-9831Article in journal (Other academic)
  • 38.
    Carlsson, Fredrik
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Karoumi, Raid
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Probabilistisk analys av Ölandsbron baserad på fordonens verkliga laster och sidopositioner2008Report (Other academic)
  • 39.
    Carlstedt, Emelie
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Soil‐structure interaction for bridges with backwalls: FE‐analysis using PLAXIS2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Bro 2004, BV Bro and the Eurocodes give guidelines for how to consider earth pressure induced by change in temperature and braking forces when designing backwalls. In this thesis those demands are investigated using PLAXIS for evaluation of the earth pressure. The results show that the model in PLAXIS corresponds quite well with the conventions in Bro 2004 and that modelling in PLAXIS gives reliable results. The demand in Bro 2004 that backwalls always shall be designed for passive earth pressure has been found to be pessimistic. In case of long bridges and short backwalls passive earth pressure is most often reached but for shorter bridge lengths in combination with longer backwalls this is almost never the case. It was also found that PLAXIS is sensitive and that the structure of the model and the choice of input are essential. A model in PLAXIS doesn’t make the design more effective but it may be a good tool for analysing the effect of the earth pressure combined with other effects such as the patterns for displacement as well as moment- and force distributions.

  • 40.
    Danielsson, Fredrik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Jämförelse och analys av olika dimensioneringsmetoder för dimensionering av betongsilos2008Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 41.
    Diogo Honório, José
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Conceptual design of long-span cantilever constructed concrete bridges2007Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 42.
    Du, Guangli
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    A Literature review of life cycle assessment for bridge infrastructure2010In: Sustainable Construction A Life Cycle Approach in Engineering: Proceedings International Symposium / [ed] L. Bragança, H. Koukkari, M. Veljkovic and R. P. Borg, Faculty for the Built Environment, University of Malta , 2010Conference paper (Refereed)
    Abstract [en]

    Currently, the whole world is confronted with great challenges related to environmental issues. As a fundamentalinfrastructure in transport networks, railway bridges are responsible for numerous material and energy consumption throughtheir life cycle, which in turn leads to significant environmental burdens. However, present management of railway bridgeinfrastructures is mainly focused on the technical and financial aspects, whereas the environmental assessment is rarelyintegrated. Life cycle assessment (LCA) is deemed as a systematic method for also assessing the environmental impact ofproducts and systems, but its application in railway bridge infrastructures is rare. Very limited literature and research studiesare available in this area. In order to incorporate the implementation of LCA into railway bridges and set new design criteria,this article performs an elaborate literature survey and presents current developments regarding the LCA implementation forrailway bridges. Several critical issues are discussed and highlighted in detail. The discussion is focused on themethodology, practical operational issues and data collections. Finally, a systematic LCA framework for quantifyingenvironmental impacts for railway bridges is introduced and interpreted as a potential guideline.

  • 43.
    Du, Guangli
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Karoumi, Raid
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    LCA of Railway Bridge: a comparison between two superstructure designs2013In: Structure and Infrastructure Engineering, ISSN 1573-2479, Vol. 9, no 11, 1149-1160 p.Article in journal (Refereed)
    Abstract [en]

    Railway bridges currently encounter the challenges of increasing the load capacity while the environmental sustainability should be achieved. However, it has been realised that the environmental assessment of railway bridges has not been integrated into the decision-making process, the standard guideline and criterion is still missing in this field. Therefore, the implementation of life cycle assessment (LCA) method is introduced into railway bridges. This article provides a systematic bridge LCA model as a guideline to quantify the environmental burdens for the railway bridge structures. A comparison case study between two alternative designs of Banafjäl Bridge is further carried out through the whole life cycle, with the consideration of several key maintenance and end-of-life scenarios. Six impact categories are investigated by using the LCA CML 2001 method and the known life cycle inventory database. Results show that the fixed-slab bridge option has a better environmental performance than the ballasted design due to the ease of maintenances. The initial material manufacture stage is responsible for the largest environmental burden, while the impacts from the construction machinery and material transportations are ignorable. Sensitivity analysis illustrates the maintenance scenario planning and steel recycling have the significant influence on the final results other than the traffic disturbances.

  • 44.
    Eklund, Alice
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Measurement and Evaluation of Cable Forces in the Älvsborg Bridge2006Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 45.
    Enckell, Merit
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Lessons Learned in Structural Health Monitoring of Bridges Using Advanced Sensor Technology2011Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Structural Health Monitoring (SHM) with emerging technologies like e.g. fibre optic sensors, lasers, radars, acoustic emission and Micro Electro Mechanical Systems (MEMS) made an entrance into the civil engineering field in last decades. Expansion of new technologies together with development in data communication benefited for rapid development. The author has been doing research as well as working with SHM and related tasks nearly a decade. Both theoretical knowledge and practical experience are gained in this constantly developing field.

    This doctoral thesis presents lessons learned in SHM and sensory technologies when monitoring civil engineering structures, mostly bridges. Nevertheless, these techniques can also be used in most applications related to civil engineering like dams, high rise buildings, off-shore platforms, pipelines, harbour structures and historical monuments. Emerging and established technologies are presented, discussed and examples are given based on the experience achieved. A special care is given to Fibre Optic Sensor (FOS) technology and its latest approach. Results from crack detection testing, long-term monitoring, and sensor comparison and installation procedure are highlighted. The important subjects around sensory technology and SHM are discussed based on the author's experience and recommendations are given.

    Applied research with empirical and experimental methods was carried out. A state-of-the art-review of SHM started the process but extensive literature studies were done continuously along the years in order to keep the knowledge up to date. Several SHM cases, both small and large scale, were carried out including sensor selection, installation planning, physical installation, data acquisition set-up, testing, monitoring, documentation and reporting. One case study also included modification and improvement of designed system and physical repair of sensors as well as two Site Acceptance Tests (SATs) and the novel crack detection system testing. Temporary measuring and testing also took place and numerous Structural Health Monitoring Systems (SHMSs) were designed for new bridges. The observed and measured data/phenomena were documented and analysed. 

    Engineers, researchers and owners of structures are given an essential implement in managing and maintaining structures. Long-term effects like shrinkage and creep in pre-stressed segmental build bridges were studied. Many studies show that existing model codes are not so good to predict these long-term effects. The results gained from the research study with New Årsta Railway Bridge are biased be the fact that our structure is indeed special. Anyhow, the results can be compared to other similar structures and adequately used for the maintenance planning for the case study.

    A long-term effect like fatigue in steel structures is a serious issue that may lead to structural collapse. Novel crack detection and localisation system, based on development on crack identification algorithm implemented in DiTeSt system and SMARTape delamination mechanism, was developed, tested and implemented. Additionally, new methods and procedures in installing, testing, modifying and improving the installed system were developed.

    There are no common procedures how to present the existing FOS techniques. It is difficult for an inexperienced person to judge and compare different systems. Experience gained when working with Fibre Optic Sensors (FOS) is collected and presented. The purpose is, firstly to give advice when judging different systems and secondly, to promote for more standardised way to present technical requirements. Furthermore, there is need to regulate the vocabulary in the field.

    Finally, the general accumulated experience is gathered. It is essential to understand the complexity of the subject in order to make use of it. General trends and development are compared for different applications. As the area of research is wide, some chosen, specific issues are analysed on a more detailed level. Conclusions are drawn and recommendations are given, both specific and more general. SHMS for a complex structure requires numerous parameters to be measured. Combination of several techniques will enable all required measurements to be taken. In addition, experienced specialists need to work in collaboration with structural engineers in order to provide high-quality systems that complete the technical requirement. Smaller amount of sensors with proper data analysis is better than a complicated system with numerous sensors but with poor analysis. Basic education and continuous update for people working with emerging technologies are also obligatory.

    A lot of capital can be saved if more straightforward communication and international collaboration are established: not only the advances but also the experienced problems and malfunctions need to be highlighted and discussed in order not to be repeated. Quality assurance issues need to be optimized in order to provide high quality SHMSs. Nevertheless, our structures are aging and we can be sure that the future for sensory technologies and SHM is promising.

    The final conclusion is that an expert in SHM field needs wide education, understanding, experience, practical sense, curiosity and preferably investigational mind in order to solve the problems that are faced out when working with emerging technologies in the real world applications.  The human factor, to be able to bind good relationship with workmanship cannot be neglected either. There is also need to be constantly updated as the field itself is in continuous development.

  • 46.
    Enckell, Merit
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    New Årsta Railway Bridge: A Long Term SHM Case Study with Fibre Optic Sensors2011In: Nordic Concrete Research: 30 September 2011, 2011Conference paper (Other academic)
  • 47.
    Enckell, Merit
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    STRUCTURAL HEALTH MONITORING OF BRIDGES IN SWEDEN2007In: PROCEEDINGS OF THE 3RD INTERNATIONAL CONFERENCE ON STRUCTURAL HEALTH MONITORING & INTELLIGENT INFRASTRUCTURE: STRUCTURAL HEALTH MONITORING & INTELLIGENT INFRASTRUCTURE / [ed] Bakht B, Mufti A, MANITOBA: ISHMII-INT SOC STRUCTURAL HEALTH MONITORING INTELLIGENT INFRASTRUCTURE , 2007, U295-U303 p.Conference paper (Refereed)
    Abstract [en]

    Measuring insecure parameters in constructions has taken place in the past. However, the measuring was small in scale and aimed at pure verification of desired parameters rather than for economical, security or maintenance aspects. Organized Structural Health Monitoring (SHM) activities of bridges in Sweden have begun in recent years when some innovative bridges with complicated design were constructed. Several old and/or deteriorated bridges needed upgrading and classification and benefited from SHM. Both large scale and long-term projects were initiated; as well as some more moderate projects. Planning of data acquisition, installation of sensors, data storage and analysis were very demanding and a lot of heuristic knowledge was gathered. New techniques were also introduced and some preliminary fibre optic installations took place. A lot of practical experience was obtained when working in the field with fibre optic sensors, especially when handling distributed fibre optic sensors. This paper introduces some projects and results in short, and highlights conclusions. Special care is paid to reasons for monitoring, issues in planning, monitoring and practices in fibre optic installation procedures.

  • 48.
    Enckell, Merit
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Structural health monitoring using modern sensor technology: long-term monitoring of the New Årsta Railway Bridge2006Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    Structural Health Monitoring (SHM) is a helpful tool for engineers in order to control and verify the structural behaviour. SHM also guides the engineers and owners of structures in decision making concerning the maintenance, economy and safety of structures. Sweden has not a very sever tradition in monitoring, as countries with strong seismic and/or aerodynamic activities. Anyway, several large scale monitoring projects have taken place in recent years and SHM is slowly making entrance as an essential implement in managing structures by engineers as well as owners.

    This licentiate thesis presents a state-of-the art-review of health monitoring activities and over sensory technologies for monitoring infrastructure constructions like bridges, dams, off-shore platforms, historical monuments etc. related to civil engineering. The fibre optic equipment is presented with special consideration.

    The permanent monitoring system of the New Årsta Bridge consists of 40 fibre optic sensors, 20 strain transducers, 9 thermocouples, 6 accelerometers and one LVDT. The aims of the static study are: to control the maximal strains and stresses; to detect cracking in the structure; to report strain changes under construction, testing period and in the coming 10 years; and to compare conventional system with fibre optic system.

    The system installation started in January 2003 and was completed October 2003. The measurements took place from the very beginning and are suppose to continue for at least 10 years of operation. At the construction phase the measurements were performed manually and later on automatically through broad band connection between the office and central data acquisition systems located inside the bridge.

    The monitoring project of the New Årsta Railway Bridge is described from the construction phase to the testing phase of the finished bridge. Results of the recorded statistical data, crack detection and loading test are presented and a comparison between traditional techniques like strain transducers and fibre optic sensors is done.

    Various subjects around monitoring and sensor technologies that were found under the project are brought up in order to give the reader a good understanding, as well of the topics, techniques and of the bridge. Example of few applications is given with the aim of a deeper insight into monitoring related issues.

  • 49.
    Enckell, Merit
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Silfwerbrand, Johan L.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges.
    Gathered Knowledge of Structural Health Monitoring of Bridges with Fibre Optic Sensors2011In: Proceedings of the ICE - Bridge Engineering: on 13 October 2011, 2011Conference paper (Other academic)
  • 50.
    Enckell, Merit
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Wiberg, Johan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Design and Bridges (name changed 20110630).
    Monitoring of the New Årsta Railway Bridge. Presentation of measured data and report on the monitoring system over the period 2003-20072008Report (Other academic)
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