Academic literature on the topic 'Design and assessment of bridge structures'
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Journal articles on the topic "Design and assessment of bridge structures"
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Cheung, M. S., and W. C. Li. "Reliability assessment in highway bridge design." Canadian Journal of Civil Engineering 29, no. 5 (October 1, 2002): 799–805. http://dx.doi.org/10.1139/l02-079.
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The current practice of highway bridge design in Canada is based on limit states design. Ideally, by means of the properly calibrated load and resistance factors specified in the applicable design code, limit states design will yield a consistent and uniform safety level for all designed bridge structures. Some factors neglected in the standard design procedures, however, may have unexpected effects on the reliability of a particular design. In this case, to follow a design code exactly may still lead to a certain degree of underdesign or overdesign. Therefore, the reliability assessment is recommended for each particular design, and a simulation-based approach for this assessment is proposed in this study. Examples are presented to support the afore-mentioned recommendation.Key words: highway bridges, reliability, design code, simulation, finite strip method.
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Naser, Ali Fadhil, Hussam Ali Mohammed, and Ayad Ali Mohammed. "Seismic Design Assessment of Bridge Piers Location Effect on the Structural Capacity of Supports under Earthquake Action." International Journal of Safety and Security Engineering 11, no. 2 (April 30, 2021): 143–53. http://dx.doi.org/10.18280/ijsse.110203.
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The objective of this study was to assess the seismic performance of two types of bridges structures under effect of earthquake by using different locations and numbers of piers. The results of D/C ratio showed that simply supported I girder bridge appeared higher structural capacity than continuous box girder bridge which was resisted the seismic demand. Continuous box girder bridge had higher seismic demand and lower structural capacity comparing with simply supported I girder bridge. Commonly, the seismic design for two types of bridges models with increasing of piers numbers was suitable to resist the earthquake action for region type B. The results of non-linear static analysis (pushover method) showed that the increasing of piers numbers had significant effects on the seismic design of bridges structures to increase the displacement capacity, force capacity, and decreasing of seismic demand to reduce the effects of earthquake action on the bridges structural members. The bridge type simply supported I girder had higher capacity in longitudinal direction than continuous box girder bridge. Whereas, for continuous box girder bridge appeared higher capacity in transverse direction than simply supported I girder. The performance points which were based on displacement were decreased with increasing the piers numbers for bridges structures supports.
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Milani, Cleovir José, Víctor Yepes, and Moacir Kripka. "Proposal of Sustainability Indicators for the Design of Small-Span Bridges." International Journal of Environmental Research and Public Health 17, no. 12 (June 22, 2020): 4488. http://dx.doi.org/10.3390/ijerph17124488.
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The application of techniques to analyze sustainability in the life cycle of small-span bridge superstructures is presented in this work. The objective was to obtain environmental and economic indicators for integration into the decision-making process to minimize the environmental impact, reduce resource consumption and minimize life cycle costs. Twenty-seven configurations of small-span bridges (6 to 20 m) of the following types were analyzed: steel–concrete composite bridges, cast in situ reinforced concrete bridges, precast bridges and prestressed concrete bridges, comprising a total of 405 structures. Environmental impacts and costs were quantified via life cycle environmental assessment and life cycle cost analysis following the boundaries of systems from the extraction of materials to the end of bridge life (“from cradle to grave”). In general, the results indicated that the environmental performance of the bridges was significantly linked to the material selection and bridge configuration. In addition, the study enabled the identification of the products and processes with the greatest impact in order to subsidize the design of more sustainable structures and government policies.
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Hose, Yael, Pedro Silva, and Frieder Seible. "Development of a Performance Evaluation Database for Concrete Bridge Components and Systems under Simulated Seismic Loads." Earthquake Spectra 16, no. 2 (May 2000): 413–42. http://dx.doi.org/10.1193/1.1586119.
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Through lessons learned in recent earthquakes, the need for new seismic bridge design methodologies that consider structural performance explicitly and address the inelastic response of bridge structures more directly is recognized. Efforts are in progress to define and quantify limit states and associated performance goals to develop a multi-level bridge design methodology. A multi-level design approach can only be implemented, however, when structural behavior or limit states can accurately be characterized and assessed for the wide range of probable input or demands. The outlined capacity assessment database addresses the response determination and parameterization of bridge components, sub-assemblages, and systems in direct support of the development of multi-level performance design and evaluation procedures for bridges. Through the use of a standardized template, a performance library for bridge structures, which is open for access and expansion to the entire practicing bridge engineering community, has been initiated.
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Yang, Yang, He Liu, and Khalid M. Mosalam. "An Improved Direct Stiffness Calculation Technique for Damage Detection of Bending Structures." Advanced Materials Research 368-373 (October 2011): 2224–28. http://dx.doi.org/10.4028/www.scientific.net/amr.368-373.2224.
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In this paper, a practical application for a continues beam-type bridge, the Truckee river bridge, California, to test the validity of the improved DSC method in the identification of the bridge damage after severe loading such as that caused by an earthquake was discussed. Comparing the calculated stiffness from the improved DSC method with that from design data of the bridge based on the numerical simulation with different damage scenarios in consideration of measurement errors, the location and severity of the damage in the bridge can be accurately and reliably detected. The pushover and seismic damage assessment analysis shows that the improved DSC is valid and efficient for damage detection in highway bridges.
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Kvasha, V. H., A. Ya Muryn, and L. V. Salyichuk. "ASSESSMENT OF TECHNICAL STATE AND DESIGN OF RECONSTRUCTION OF THE SMALL BRIDGE OF THE SLOVINSKY SYSTEM." Bulletin of Odessa State Academy of Civil Engineering and Architecture, no. 81 (December 7, 2020): 52–65. http://dx.doi.org/10.31650/2415-377x-2020-81-52-65.
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Abstract. In the 1950s and 1960s of the 20th century a lot of one- and two-span bridges with a span of 4-6 m were built on public roads on the territory of the former USSR. The paper describes the features of the design and construction of small four-hinged reinforced concrete bridges on lightweight supports of engineer Slovinsky system. The experience of surveying small bridges shows that in the context of a limited funding, compared to other types of bridges, maintenance and operation of these bridges does not get enough attention. There are relatively low material losses from their destruction and it is possible to restore them fairly easily. Therefore, many of them have a large number of defects and are in a poor physical condition. The purpose of the work is to draw attention of owners to the problems of small bridges using a specific example, as well as to present effective constructive solutions for the reconstruction of a small four-hinge bridge. These design solutions are developed on the basis of the research and development in Lviv National Polytechnic University and include the use of a reinforced concrete cover slab. The slab has been frequently used in other bridge reconstruction projects and proved its technical and economic efficiency in practice. The article gives characteristics of the bridge, the technical state of its structures, the main defects and damages, as well as the characteristics of the stream and its influence on the condition of the bridge. The design solutions for widening and strengthening the small bridge of the Slovinsky system can provide operational performance and consumer properties in accordance with the requirements of the current design standards for new bridges. These standards are able to ensure the service life of the reconstructed bridge.
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Kawashima, Kazuhiko. "Introduction to Dr. Iwasaki’s Paper Entitled “Response Analysis of Civil Engineering Structures Subjected to Earthquake Motions”." Journal of Disaster Research 1, no. 2 (October 1, 2006): 272–73. http://dx.doi.org/10.20965/jdr.2006.p0272.
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Seismic design of Japanese bridges started in 1925, triggered by the extensive damage of the 1923 Kanto earthquake. "Drafted Structural Details of Road Structures," issued by Japan's Ministry of the Interior in 1925, recommended the use of static seismic analysis based on working stress design, which was used for a long time. "Design Specifications of Steel Bridges," issued by the Japan Road AssoCiation in 1964, was an important code used for design of a number of bridges during restoration after World War II and the early high economic growth periods that followed. There was no independent seismic design code in those days, so only limited descriptions were provided for seismic design, e.g., pages in the code related to seismic design numbered only 2 or 3, and seismic knowledge was limited. Most bridges damaged in the 1995 Kobe earthquake were designed based on this code. Extensive damage in the 1964 Niigata earthquake initiated intensified research on the structural response and seismic design of bridges. Accomplishments of research were reflected in the 1971 "Guide Specifications on Seismic Design of Bridges" (Japan Road Association), the first design guidelines focusing on the seismic design of bridges. Pages of the main text and explanations related to seismic design increased to 30, and included the natural period dependent lateral seismic coefficient and preliminary evaluation of soil liquefaction assessment and unseating prevention devices. This was the first time that preliminary liquefaction assessment and unseating prevention devices innovated by Japanese bridge engineers were included in bridge codes. The 1971 Guide Specification of Seismic Design of Bridges was compiled with other design codes and issued in 1980 as "Part V Seismic Design" of "Design Specifications of Highway Bridges" (Japan Road Association). Assessment of soil liquefaction based on FL was introduced in Part V, but other parts remained almost unchanged. Part V was completely revised in 1990 to include (1) new static analysis evaluating lateral force in continuous bridges based on the stiffness of superstructures and substructures, (2) safety evaluation (level 2) ground motion for the design of reinforced concrete columns, and (3) design response spectra and design-spectra-compatible ground acceleration for dynamic response analysis. This was the first in Japan to include safety evaluation ground motion and static design for ductility evaluation of bridge columns. Pages on code related to seismic design increased to 96 greatly enhanced as a modern seismic design code. Based on the extensive damage sustained in the 1995 Kobe earthquake, Part V on seismic design was further revised in 1996 and 2002 to include lessons learned from this damage. Pages of code related to seismic design increased to 227 in the 1996 code and 280 in the 2002 code. Figure 1 shows the increase in the number of pages related to seismic design. Extensive improvement was conducted in 1990 and 1996. Although we have had over 80 years in experience of seismic bridge design, only in the last 15 years has seismic bridge design been enhanced to include modern requirements. Codes before the 1971 Guide Specification and the 1980 Part V on seismic design had insufficient scientific knowledge, although they were used for design in a number of bridges. The paper by Dr. Iwasaki has contributed much to establishing modern seismic design codes for bridges. His contributions include, but are not limited to, the clarification of dynamic response characteristics of bridges based on extensive field measurements, the deployment of strong motion recording networks, the development of soil liquefaction evaluation based on FL, and the development of ground motion attenuation equations. All of his activities and research helped enhance seismic design codes for bridges in Japan.
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Lee, Min-Woo, Ji-Hyun Lee, Yeon-Seung Lee, Hyun-Jin Park, and Tak-Kee Lee. "Safety Assessment for Upper Part of Floating Crane Considering Minimum Luffing Angle." Applied Sciences 11, no. 11 (May 31, 2021): 5104. http://dx.doi.org/10.3390/app11115104.
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Floating cranes are used for the construction and installation work of harbors, various heavy industries, and offshore structures. In the case of floating cranes that need to move around the work site, their navigation can be constrained due to marine bridges. In some cases, the clearance under the bridge between the water surface and the bottom of the marine bridge may be too low, and floating cranes cannot pass under the marine bridge. In this study, the height of the marine bridges and the boom height of the floating cranes considering the minimum luffing angle were investigated. Through minimizing the boom luffing angle of the floating crane by the height of back tower, a floating crane with improved mobility through marine bridges was developed. A structural analysis model was produced to check whether the developed crane design satisfies the design criteria obeying the KR, DNVGL, and ABS rules, including luffing condition as a special consideration. As a result of the structural analyses, structural safety was validated for the service, stowage, and luffing conditions in terms of combined stresses, displacements, and buckling.
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Stewart, Mark G. "Reliability-based bridge design and assessment." Progress in Structural Engineering and Materials 1, no. 2 (January 1998): 214–22. http://dx.doi.org/10.1002/pse.2260010215.
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Park, R. "Developments in seismic design procedures for bridges in New Zealand." Bulletin of the New Zealand Society for Earthquake Engineering 30, no. 2 (June 30, 1997): 177–84. http://dx.doi.org/10.5459/bnzsee.30.2.177-184.
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Progress on developments in the seismic design procedures for bridges in New Zealand is outlined. The current approach has evolved from the recommendations of a study group of the New Zealand National Society for Earthquake Engineering which was published in 1980. Research and development into the determination of the design seismic force and ductility demand, the capacity design approach, the detailing of bridge columns for adequate ductility, and the design approach using seismic isolation are discussed. More recent developments in New Zealand involving the assessment and retrofit of older bridge structures are also discussed and likely activities and needs of the next decade are suggested.
Dissertations / Theses on the topic "Design and assessment of bridge structures"
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Lekkas, Sotirios. "Life Cycle Assessment on Bridge Abutments : Automated Design in Structural Enginee." Thesis, KTH, Bro- och stålbyggnad, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-259573.
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Life Cycle Assessment (LCA) is the globally the most recognised method for quantifying theimpact the a product or service has on the environment through its whole life-span. Theconstruction sector plays a key role in the depletion of the natural resources and the energyconsumption on the planet. Thus it is fundamental that an environmental assessment tool likeLCA should be in close cooperation with the construction process.This thesis focuses on the environmental impact of bridge abutments, and can be divided in twoparts.The rst one focuses on enhancing the automated design in the construction eld. A Python codeis created that focuses on creating the geometry of any type of bridge abutment and conductingthe calculations for the required concrete and reinforcement. The process is attempted to becomecompletely automated.The second part introduces three alternative designs for a bridge abutment that attempt to havethe same structural properties and cooperate successfully with the superstructure, while at thesame time utilize as little material as possible. The possible reduction in material is quantiedin environmental terms after an environmental impact assessment is performed.The results show that dierent designs can have a great impact on the reduction on the materialconsumption and on the impact that the whole structure has on the environment. The resultsin this study might provide the designers with valuable motivation and guidelines to achievehigher sustainability standards in the future.
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Suchánek, Petr. "Konstrukce přemostění ve městě Příbor." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2012. http://www.nusl.cz/ntk/nusl-225698.
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This diploma thesis is focused on design and assessement of the road bridge in Příbor city, where road I/58 crosses road I/48. There are 3 possible of solution of designed structure which are slab construction, beam construction and prefabricated structure. Each solution includes the design and assessment of individual structures, including drawings and economic evaluation. In conclusion, the three solutions have been evaluated against all of the given criteria.
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Solat, Yavari Majid. "Slab Frame Bridges : Structural Optimization Considering Investment Cost and Environmental Impacts." Licentiate thesis, KTH, Bro- och stålbyggnad, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-202948.
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This research encompasses the automated design and structural optimization of reinforced concrete slab frame bridges, considering investment costs and environmental impacts. The most important feature of this work is that it focusses on realistic and complete models of slab frame bridges rather than on optimization of only individual members or sections of a bridge. The thesis consists of an extended summary of publications and three appended papers. In the first paper, using simple assumptions, the possibility of applying cost-optimization to the structural design of slab frame bridges was investigated. The results of the optimization of an existing constructed bridge showed the potential to reduce the investment cost of slab frame bridges. The procedure was further developed in the second paper. In this paper, automated design was integrated to a more refined cost-optimization methodology based on more detailed assumptions and including extra constructability factors. This procedure was then applied to a bridge under design, before its construction. From the point of view of sustainability, bridge design should not only consider criteria such as cost but also environmental performance. The third paper thus integrated life cycle assessment (LCA) with the design optimization procedure to perform environmental impact optimization of the same case study bridge as in the second paper. The results of investment cost and environmental impact optimization were then compared. The obtained results presented in the appended papers highlight the successful application of optimization techniques to the structural design of reinforced concrete slab frame bridges. Moreover, the results indicate that a multi-objective optimization that simultaneously considers both environmental impacts and investment cost is necessary in order to generate more sustainable designs. The presented methodology has been applied to the design process for a time-effective, sustainable, and optimal design of concrete slab frame bridges.QC 20170316
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Allahvirdizadeh, Reza. "Reliability-Based Assessment and Optimization of High-Speed Railway Bridges." Licentiate thesis, KTH, Bro- och stålbyggnad, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-301318.
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Increasing the operational speed of trains has attracted a lot of interest in the last decades and has brought new challenges, especially in terms of infrastructure design methodology, as it may induce excessive vibrations. Such demands can damage bridges, which in turn increases maintenance costs, endangers the safety of passing trains and disrupts passenger comfort. Conventional design provisions should therefore be evaluated in the light of modern concerns; nevertheless, several previous studies have highlighted some of their shortcomings. It should be emphasized that most of these studies have neglected the uncertainties involved, which preventsthe reported results from representing a complete picture of the problem. In this respect, the present thesis is dedicated to evaluating the performance of conventional design methods, especially those related to running safety and passenger comfort, using probabilistic approaches. To achieve this objective, a preliminary study was carried out using the first-order reliability method for short/medium span bridges passed by trains at a wide range of operating speeds. Comparison of these results with the corresponding deterministic responses showed that applying a constant safety factor to the running safety threshold does not guarantee that the safety index will be identical for all bridges. It also shows that the conventional design approaches result in failure probabilities that are higher than the target values. This conclusion highlights the need to update the design methodology for running safety. However, it would be essential to determine whether running safety is the predominant design criterion before conducting further analysis. Therefore, a stochastic comparison between this criterion and passenger comfort was performed. Due to the significant computational cost of such investigations, subset simulation and crude Monte-Carlo (MC) simulation using meta-models based on polynomial chaos expansion were employed. Both methods were found to perform well, with running safety almost always dominating the passenger comfort limit state. Subsequently, classification-based meta-models, e.g. support vector machines, k-nearest neighbours and decision trees, were combined using ensemble techniques to investigate the influence of soil-structure interaction on the evaluated reliability of running safety. The obtained results showed a significant influence, highlighting the need for detailed investigations in further studies. Finally, a reliability-based design optimization was conducted to update the conventional design method of running safety by proposing minimum requirements for the mass per length and moment of inertia of bridges. It is worth mentioning that the inner loop of the method was solved by a crude MC simulation using adaptively trained Kriging meta-models.Att öka tågens hastighet har väckt stort intresse under de senaste decennierna och har medfört nya utmaningar, särskilt när det gäller broanalyser, eftersom tågen inducerar stora vibrationer. Sådana vibrationer kan öka underhållskostnaderna, äventyra säkerheten för förbipasserande tåg och påverka passagerarkomforten. Konstruktionsbestämmelser bör därför utvärderas mot bakgrund av dessa problem; dock har flera tidigare studier belyst några av bristerna i dagens bestämmelser. Det bör understrykas att de flesta av dessa studier har försummat de osäkerheter som är involverade, vilket hindrar de rapporterade resultaten från att representera en fullständig bild av problemet. I detta avseende syftar denna avhandling till att utvärdera prestandan hos konventionella analysmetoder, särskilt de som rör körsäkerhet och passagerarkomfort, med hjälp av sannolikhetsmetoder. För att uppnå detta mål genomfördes en preliminär studie med första ordningens tillförlitlighetsnmetod för broar med kort/medellång spännvidd som passeras av tåg med ett brett hastighetsspektrum. Jämförelse av dessa resultat med motsvarande deterministiska respons visade att tillämpa en konstant säkerhetsfaktor för verifieringen av trafiksäkerhet inte garanterar att säkerhetsindexet kommer att vara identiskt för alla broar. Det visar också att de konventionella analysmetoderna resulterar i brottsannolikheter som är högre än målvärdena. Denna slutsats belyser behovet av att uppdatera analysmetoden för trafiksäkerhet. Det skulle emellertid vara viktigt att avgöra om trafiksäkerhet är det dominerande designkriteriet innan ytterligare analyser genomförs. Därför utfördes en stokastisk jämförelse mellan detta kriterium och kriteriet för passagerarkomfort. På grund av den betydande. analystiden för sådana beräkningar användes delmängdssimulering och Monte-Carlo (MC) simulering med metamodeller baserade på polynomisk kaosutvidgning. Båda metoderna visade sig fungera bra, med trafiksäkerhet som nästan alltid dominerade över gränsningstillståndet för passagerarkomfort. Därefter kombinerades klassificeringsbaserade metamodeller som stödvektormaskin och beslutsträd genom ensembletekniker, för att undersöka påverkan av jord-brointeraktion på den utvärderade tillförlitligheten gällande trafiksäkerhet. De erhållna resultaten visade en signifikant påverkan och betonade behovet av detaljerade undersökningar genom ytterligare studier. Slutligen genomfördes en tillförlitlighetsbaserad konstruktionsoptimering för att föreslå ett minimikrav på erforderlig bromassa per längdmeter och tröghetsmoment. Det är värt att nämna att metodens inre loop löstes med en MC-simulering med adaptivt tränade Kriging-metamodeller.
QC 20210910
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Dahlvik, Mathias, and Johan Eriksson. "Load Effect Modelling in Fatigue Design of Composite Bridges : An assessment of Fatigue Load Models 3, 4 and 5 according to SS-EN-1991-2 Actions on Structures – Part 2: Traffic loads on Bridges." Thesis, KTH, Stålbyggnad, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-147820.
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At the turn of 2010/2011, Sweden went from designing structures according to nationaldesign codes to the new European standards Eurocode. For bridge engineers, this implieda change from a combination of BRO 2004 and BSK 07 to the Eurocode as the maindocuments, complemented by national documents such as TRVK Bro 11. The normtransition did not only change the calculation methods, but also turned a phenomenonthat never was of great importance for road bridges before into something that could limitthe carrying capacity of the structure. This phenomenon is called fatigue, i.e. repeatedload cycles, where each load is much lower than the ultimate limit state capacity, thatfinally results in collapse. This master thesis investigates why fatigue is significant in the design today. This is donethrough a comparison of how the new and old regulations assesses fatigue. A bridge builtin 2011, designed by ELU Konsult AB according to the old regulations, was modelledin the finite element program LUSAS. Several lorry crossings from different fatigue loadmodels were then simulated. The output from LUSAS was then used to calculate theutilization ratios for three critical points along the bridge. The result indicates that both regulations give rise to similar stress ranges, i.e. thedifference between the maximum and minimum stress obtained during a crossing. Thedifferences between the regulations are instead within the fatigue calculations, where themajor difference is the number of lorries crossing the bridge during its lifetime. Theutilization ratio according to the old regulations for the worst exposed point is 27.0 %,corresponding to 9.13 daily crossings by heavy lorries, which is the maximum numberof daily crossings provided by BRO 2004. The lowest utilization ratio according tothe Eurocode is 70.0 %, calculated for 137 daily crossings which is the lowest amountof crossings allowed. An interpretation of the Eurocode, which allows usage of fatigue loadmodel 5 even for smaller bridges, results in a utilization ratio of 56.0% which correspondsto 90.0 daily crossings, i.e. lower than the other fatigue load models provided by theEurocode but clearly above the old regulations. The conclusion is that an alternative way of deciding the number of crossings shouldbe provided by the Eurocode. Today, the classification consists of four steps, which arevery rough. Instead, a proposal is given in this thesis which advocates usage of a linearfunction for deciding the number of design crossings based on the number of daily crossingsby lorries. The proposed alternative design method is between the two regulations withrespect to daily crossings and utilization ratio.Vid årsskiftet 2010/2011 övergick Sverige från att dimensionera byggnadsverk enligt nationellastandarder till den nya europastandarden Eurokod. För brokonstruktörer innebar dettaen övergång från en kombination av BRO 2004 och BSK 07, till att Eurokod blev dethuvudsakligt styrande dokumentet, med bland annat TRVK Bro 11 som ett dokumentmed tillhörande nationella val. Övergången medförde inte bara att verksamma konstruktörertvingades lära sig förändrade beräkningsmetoder, utan också att ett fenomen som tidigaresällan var dimensionerande för vägbroar nu kunde vara det som ställde högst krav påbärförmågan. Detta fenomen kallas utmattning, dvs. upprepade av- och pålastningar, varoch en betydligt lägre än brons maximala bärförmåga, som i slutändan resulterar i brott. I detta examensarbete utreds det varför utmattning numera är en betydande del avdimensioneringen. Detta sker genom en jämförelse av hur de gamla och nya normernautvärderar utmattning. Som modell har en befintlig bro invigd 2011, dimensioneradav ELU Konsult AB enligt de gamla normerna, använts. Denna bro har modellerats ifinita element programmet LUSAS, varpå en mängd olika lastbilsöverfarter simulerats ochutmattningsutnyttjandet för tre utvalda kritska punkter beräknats. Resultatet indikerar att båda normerna har liknande storlekar på spänningsvidderna,dvs. skillnaden på största och minsta spänningen som uppstår vid en överfart. Däremotråder det skillnader vid utmattningsberäkningarna, där den stora skillnaden är antalettunga fordon som passerar bron under dess livslängd. Enligt de gamla normerna ärutnyttjandegraden för den värst utsatta studerade punkten 27.0 %, vilket är beräknatpå det högsta antalet dagliga passager från tunga fordon som BRO 2004 tillåter, d.v.s.9.13 dagliga passager. Enligt Eurokod uppgår den lägsta utnyttjandegraden till 70.0 %,vilket motsvarar 137 dagliga överfarter vilket är det lägsta Eurokod tillåter. Vid ettalternativt sätt att tolka Eurokod, som tillåter användandet av utmattningslastmodell5 även för mindre broar, fås en utnyttjandegrad på 56.0% vilket motsvarar 90.0 dagligaöverfarter. Detta är något lägre än de andra utmattningslastmodellerna enligt Eurokodmen fortfarande högre än det gamla regelverket. Slutsatsen av uppsatsen är att ett alternativt sätt att bestämma antalet överfarter bordeerbjudas i Eurokod, då indelningen idag består av fyra stora trappsteg vilket ger en väldigtsnäv indelning. I detta examensarbete presenteras ett förslag som innebär att antaletdimensionerande överfarter istället bör bestämmas som en rätlinjig funktion av antaletdagliga överfarter från tung trafik. Det föreslagna sättet ligger mellan de båda normernamed hänsyn till passager och utnyttjandegrad.
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Imhof, Daniel. "Risk assessment of existing bridge structures." Thesis, University of Cambridge, 2004. https://www.repository.cam.ac.uk/handle/1810/272082.
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Wang, Naiyu. "Reliability-based condition assessment of existing highway bridges." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34835.
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Condition assessment and safety verification of existing bridges and decisions as to whether bridge posting is required are addressed through analysis, load testing, or a combination of methods. Bridge rating through structural analysis is by far the most common procedure for rating existing bridges. The American Association of State Highway and Transportation Officials (AASHTO) Manual for Bridge Evaluation (MBE), First Edition permits bridge capacity ratings to be determined through allowable stress rating (ASR), load factor rating (LFR) or load and resistance factor rating (LRFR); the latter method is keyed to the AASHTO LRFD Bridge Design Specifications, which is reliability-based and has been required for the design of new bridges built with federal findings since October, 2007. A survey of current bridge rating practices in the United States has revealed that these three methods may lead to different ratings and posting limits for the same bridge, a situation that carries serious implications with regard to the safety of the public and the economic well-being of communities that may be affected by bridge postings or closures.
To address this issue, a research program has been conducted with the overall objective of providing recommendations for improving the process by which the condition of existing bridge structures is assessed. This research required a coordinated program of load testing and finite element analysis of selected bridges in the State of Georgia to gain perspectives on the behavior of older bridges under various load conditions. Structural system reliability assessments of these bridges were conducted and bridge fragilities were developed for purposes of comparison with component reliability benchmarks for new bridges. A reliability-based bridge rating framework was developed, along with a series of recommended improvements to the current bridge rating methods, which facilitate the incorporation of various in situ conditions of existing bridges into the bridge rating process at both component and system levels. This framework permits bridge ratings to be conducted at three levels of increasing complexity to achieve the performance objectives, expressed in the terms of reliability, that are embedded in the LRFR option of the AASHTO Manual of Bridge Evaluation. This research was sponsored by the Georgia Department of Transportation, and has led to a set of Recommended Guidelines for Condition Assessment and Evaluation of Existing Bridges in Georgia.
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Shahsavari, Vahid. "Condition assessment of bridge structures using statistical analysis of wavelets." Doctoral thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/27720.
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La surveillance à distance des structures a émergé comme une préoccupation importante pour les ingénieurs afin de maintenir la sécurité et la fiabilité des infrastructures civiles pendant leur durée de vie. Les techniques de surveillance structurale (SHM) sont de plus en plus populaires pour fournir un diagnostic de "l'état" des structures en raison de leur vieillissement, de la dégradation des matériaux ou de défauts survenus pendant leur construction. Les limites de l'inspection visuelle et des techniques non destructives, qui sont couramment utilisées pour détecter des défauts extrêmes sur les parties accessibles des structures, ont conduit à la découverte de nouvelles technologies qui évaluent d’un seul tenant l'état global d'une structure surveillée. Les techniques de surveillance globale ont été largement utilisées pour la reconnaissance d'endommagement dans les grandes infrastructures civiles, telles que les ponts, sur la base d'une analyse modale de la réponse dynamique structurale. Cependant, en raison des caractéristiques complexes des structures oeuvrant sous des conditions environnementales variables et des incertitudes statistiques dans les paramètres modaux, les techniques de diagnostic actuelles n'ont pas été concluantes pour conduire à une méthodologie robuste et directe pour détecter les incréments de dommage avant qu'ils n'atteignent un stade critique. C’est ainsi que des techniques statistiques de reconnaissance de formes sont incorporées aux méthodes de détection d'endommagement basées sur les vibrations pour fournir une meilleure estimation de la probabilité de détection des dommages dans des applications in situ, ce qui est habituellement difficile compte tenu du rapport bruit à signal élevé. Néanmoins, cette partie du SHM est encore à son stade initial de développement et, par conséquent, d'autres tentatives sont nécessaires pour parvenir à une méthodologie fiable de détection de l'endommagement. Une stratégie de détection de dommages basée sur des aspects statistiques a été proposée pour détecter et localiser de faibles niveaux incrémentiels d'endommagement dans une poutre expérimentale pour laquelle tant le niveau d'endommagement que les conditions de retenue sont réglables (par exemple ancastrée-ancastrée et rotulée-rotulée). Premièrement, des expériences ont été effectuées dans des conditions de laboratoire contrôlées pour détecter de faibles niveaux d'endommagement induits (par exemple une fissure correspondant à 4% de la hauteur d’une section rectangulaire équivalente) simulant des scénarios d'endommagement de stade précoce pour des cas réels. Différents niveaux d'endommagement ont été simulés à deux endroits distincts le long de la poutre. Pour chaque série d'endommagement incrémentiel, des mesures répétées (~ 50 à 100) ont été effectuées pour tenir compte de l'incertitude et de la variabilité du premier mode de vibration de la structure en raison d'erreurs expérimentales et du bruit. Une technique d'analyse par ondelette basée sur les modes a été appliquée pour détecter les changements anormaux survenant dans les modes propres causées par le dommage. La réduction du bruit ainsi que les caractéristiques des agrégats ont été obtenues en mettant en œuvre l'analyse des composantes principales (PCA) pour l'ensemble des coefficients d'ondelettes calculés à des nœuds (ou positions) régulièrement espacés le long du mode propre. En rejetant les composantes qui contribuent le moins à la variance globale, les scores PCA correspondant aux premières composantes principales se sont révélés très corrélés avec de faibles niveaux d'endommagement incrémentiel. Des méthodes classiques d'essai d'hypothèses ont été effectuées sur les changements des paramètres de localisation des scores pour conclure objectivement et statistiquement, à un niveau de signification donné, sur la présence du dommage. Lorsqu'un dommage statistiquement significatif a été détecté, un nouvel algorithme basé sur les probabilités a été développé pour déterminer l'emplacement le plus probable de l'endommagement le long de la structure. Deuxièmement, se basant sur l'approche probabiliste, une série de tests a été effectuée dans une chambre environnementale à température contrôlée pour étudier les contributions relatives des effets de l’endommagement et de la température sur les propriétés dynamiques de la poutre afin d’estimer un facteur de correction pour l'ajustement des scores extraits. Il s'est avéré que la température avait un effet réversible sur la distribution des scores et que cet effet était plus grand lorsque le niveau d'endommagement était plus élevé. Les résultats obtenus pour les scores ajustés indiquent que la correction des effets réversibles de la température peut améliorer la probabilité de détection et minimiser les fausses alarmes. Les résultats expérimentaux indiquent que la contribution combinée des algorithmes utilisés dans cette étude était très efficace pour détecter de faibles niveaux d'endommagement incrémentiel à plusieurs endroits le long de la poutre tout en minimisant les effets indésirables du bruit et de la température dans les résultats. Les résultats de cette recherche démontrent que l'approche proposée est prometteuse pour la surveillance des structures. Cependant, une quantité importante de travail de validation est attendue avant sa mise en œuvre sur des structures réelles. Mots-clés : Détection et localisation des dommages, Poutre, Mode propre, Ondelette, Analyse des composantes principales, Rapport de probabilité, TempératureRemote monitoring of structures has emerged as an important concern for engineers to maintain safety and reliability of civil infrastructure during its service life. Structural Health Monitoring (SHM) techniques are increasingly becoming popular to provide ideas for diagnosis of the "state" of potential defects in structures due to aging, deterioration and fault during construction. The limitations of visual inspection and non-destructive techniques, which were commonly used to detect extreme defects on only accessible portions of structures, led to the discovery of new technologies which assess the "global state" of a monitored structure at once. Global monitoring techniques have been used extensively for the recognition of damage in large civil infrastructure, such as bridges, based on modal analysis of structural dynamic response. However, because of complicated features of real-life structures under varying environmental conditions and statistical uncertainties in modal parameters, current diagnosis techniques have not been conclusive in ascertaining a robust and straightforward methodology to detect damage increments before it reaches its critical stage. Statistical pattern recognition techniques are incorporated with vibration-based damage detection methods to provide a better estimate for the probability of the detection of damage in field applications, which is usually challenging given the high noise to signal ratio. Nevertheless, this part of SHM is still in its initial stage of development and, hence, further attempts are required to achieve a reliable damage detection methodology. A statistical-based damage detection strategy was proposed to detect and localize low levels of incremental damage in an experimental beam in which the level of damage and beam restraint conditions are adjustable (e.g. fixed-fixed and pinned-pinned). First, experiments were performed in controlled laboratory conditions to detect small levels of induced-damage (e.g. 4% crack height for an equivalent rectangular section) simulated for early stage damage scenarios in real cases. Various levels of damage were simulated at two distinct locations along the beam. For each sate of incremental damage, repeat measurements (~ 50 to 100) were performed to account for uncertainty and variability in the first vibration mode of the structure due to experimental errors and noise. A modal-based wavelet analysis technique was applied to detect abnormal changes occurring in the mode shapes caused by damage. Noise reduction as well as aggregate characteristics were obtained by implementing the Principal Component Analysis (PCA) into the set of wavelet coefficients computed at regularly spaced nodes along the mode shape. By discarding components that contribute least to the overall variance, the PCA scores corresponding to the first few PCs were found to be highly correlated with low levels of incremental damage. Classical hypothesis testing methods were performed on changes on the location parameters of the scores to conclude damage objectively and statistically at a given significance level. When a statistically significant damage was detected, a novel Likelihood-based algorithm was developed to determine the most likely location of damage along the structure. Secondly, given the likelihood approach, a series of tests were carried out in a climate-controlled room to investigate the relative contributions of damage and temperature effects on the dynamic properties of the beam and to estimate a correction factor for the adjustment of scores extracted. It was found that the temperature had a reversible effect on the distribution of scores and that the effect was larger when the damage level was higher. The resulted obtained for the adjusted scores indicated that the correction for reversible effects of temperature can improve the probability of detection and minimize false alarms. The experimental results indicate that the combined contribution of the algorithms used in this study were very efficient to detect small-scale levels of incremental damage at multiple locations along the beam, while minimizing undesired effects of noise and temperature in the results. The results of this research demonstrate that the proposed approach may be used as a promising tool for SHM of actual structures. However, a significant amount of challenging work is expected for implementing it on real structures. Key-words: Damage Detection and Localization, Beam, Mode Shape, Wavelet, Principal Component Analysis, Likelihood Ratio, Temperature
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Wu, Shuanglan. "Near-fault Ground Motions for Seismic Design of Bridge Structures." Kyoto University, 2018. http://hdl.handle.net/2433/232017.
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Webster, Michael Peter. "The assessment of corrosion-damaged concrete structures." Thesis, University of Birmingham, 2000. http://etheses.bham.ac.uk//id/eprint/259/.
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Data from existing research are linked together to produce an overview of the effects of chloride-induced corrosion on reinforced concrete structures. The effects of chloride-induced corrosion on the following mechanisms have been investigated: (i) Cracking. (ii) Bond strength. (iii) Flexural strength. (iv) Shear strength. (v) Column behaviour. Models have been developed to link material and structural aspects of deterioration. Despite the complexity of the behaviour, many of the models are modifications to existing procedures contained in UK codes. Material and structural models are integrated together in a spreadsheet for assessing the variation in load-carrying capacity with time. Time to cracking and residual load-carrying capacity are found to be sensitive to small variations in key parameters such as the cover and the surface chloride level. Predictions from a spreadsheet model indicate that structures designed and built to BS 8110 should achieve their design life without the need for significant repair. The predictions also indicate that the UK Highways Agency was justified in making BD 57 more onerous than BS 5400. With validation against further test data the procedures developed in this Thesis could form the basis for codes of practice for the assessment of corrosion-damaged concrete structures and the durability design of new concrete structures.
Books on the topic "Design and assessment of bridge structures"
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Casarotti, Chiara. Adaptive pushover-based methods for seismic assessment and design of bridge structures. Pavia, Italy: IUSS Press, 2005.
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Borri, Claudio, and Claudio Mannini, eds. Aeroelastic Phenomena and Pedestrian-Structure Dynamic Interaction on Non-Conventional Bridges and Footbridges. Florence: Firenze University Press, 2010. http://dx.doi.org/10.36253/978-88-6453-202-8.
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Fluid-structure and pedestrian-structure interaction phenomena are extremely important for non-conventional bridges. The results presented in this volume concern: simplified formulas for flutter assessment; innovative structural solutions to increase the aeroelastic stability of long-span bridges; numerical simulations of the flow around a benchmark rectangular cylinder; examples of designs of large structures assisted by wind-tunnel tests; analytical, computational and experimental investigation of the synchronisation mechanisms between pedestrians and footbridge structures. The present book is addressed to a wide audience including professionals, doctoral students and researchers, aiming to increase their know-how in the field of wind engineering, bluff-body aerodynamics and bridge dynamics.
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Anderson, John E., Christian Bucher, Bruno Briseghella, Xin Ruan, and Tobia Zordan, eds. Sustainable Structural Engineering. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2015. http://dx.doi.org/10.2749/sed014.
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<p>Sustainability is the defining challenge for engineers in the twenty-first century. In addition to safe, economic, and effi-cient structures, a new criterion, sustainable, must be met. Furthermore, this new design paradigm–addressing social, economic, and environmental aspects–requires prompt action. In particular, mitigation of climate change requires sustainable solutions for new as well as existing structures. Taking from both practice and research, this book provides engineers with applicable, timely, and innovative information on the state-of-the-art in sustainable structural design. <p>This Structural Engineering Document addresses safety and regulations, integration concepts, and a sustainable approach to structural design. Life-cycle assessment is presented as a critical tool to quantify design options, and the importance of existing structures–in particular cultural heritage structures–is critically reviewed. Consideration is also given to bridge design and maintenance, structural reassessment, and disaster risk reduction. Finally, the importance of environmentally friendly concrete is examined. Consequently, structural engineers are shown to have the technical proficiency, as well as ethical imperative, to lead in designing a sustainable future.
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Marsh, M. Lee. Performance-based seismic bridge design. Washington, D.C: Transportation Research Board, 2013.
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Chamis, C. C. Probabilistic assessment of smart composite structures. [Washington, DC]: National Aeronautics and Space Administration, 1993.
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Wang, Naiyu. Condition assessment of existing bridge structures: Report of task [number]. Georgia: Georgia Institute of Technology School of Civil and Environmental Engineering, 2009.
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M, Doherty Katherine, ed. The Golden Gate Bridge. Woodbridge, Conn: Blackbirch Press, 1995.
Find full textBook chapters on the topic "Design and assessment of bridge structures"
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Jara, Jose M., Bertha A. Olmos, and Guillermo Martínez. "Strengthening and Retrofitting of Motín de Oro II Bridge in Mexico." In Case Studies on Conservation and Seismic Strengthening/Retrofitting of Existing Structures, 193–209. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2020. http://dx.doi.org/10.2749/cs002.193.
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This chapter presents the studies conducted to retrofit an existing bridge in a seismic prone area of Mexico. The Motín de Oro II Bridge was built in the 1970s with a continuous box girder superstructure and wall-type substructure. From the 1970s to nowadays, the design truck loads in Mexico have been substantially incremented and many bridges built in that period have required to be evaluated and, in some cases, rehabilitated and retrofitted. Firstly, the study presents the results of visual inspections of all parts of the bridge and a description of the preliminary studies conducted to determine the material properties, to evaluate the river flow characteristics and to calculate the scour depth. Secondly, the chapter discusses the initial structural analyses of the bridge subjected to the original gravitational and seismic loads and to the current loads before the intervention. These analyses allow to select the structural elements that require to be retrofitted and the best strategy to follow. Finally, the study presents results of the numerical retrofitted model and the experimental assessment of the dynamic properties based on ambient vibration measurements. Additionally, the scour protection and the general construction procedure are also described.
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Middleton, Campbell. "Bridge Assessment." In Modeling Complex Engineering Structures, 77–102. Reston, VA: American Society of Civil Engineers, 2007. http://dx.doi.org/10.1061/9780784408506.ch04.
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Uhl, Tadeusz, Artur Hanc, Krzysztof Tworkowski, and Łukasz Sekiewicz. "Wireless Sensor Network Based Bridge Monitoring System." In Damage Assessment of Structures VII, 499–504. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-444-8.499.
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Wang, Chun Sheng, Hui Qian, Ang Zhan, Yue Xu, and Da Lin Hu. "Fatigue and Fracture Evaluation of a 70 Year Old Steel Bridge." In Damage Assessment of Structures VII, 359–64. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-444-8.359.
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Dang, Ji. "Seismic Risk-Based Design for Bridge." In Reliability-Based Analysis and Design of Structures and Infrastructure, 275–84. Boca Raton: CRC Press, 2021. http://dx.doi.org/10.1201/9781003194613-18.
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Kim, Chul Woo, M. Kawatani, M. Tsukamoto, and N. Fujita. "Wireless Sensor Node Development for Bridge Condition Assessment." In Emboding Intelligence in Structures and Integrated Systems, 573–78. Stafa: Trans Tech Publications Ltd., 2008. http://dx.doi.org/10.4028/3-908158-13-3.573.
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Chowdhury, Indrajit, and Shambhu P. Dasgupta. "Earthquake Response of Bridge Piers and Their Foundations." In Earthquake Analysis and Design of Industrial Structures and Infra-structures, 863–918. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-90832-8_12.
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Kiss, Csaba. "Optimal Way of Bridge Crane Track Welding." In Design, Fabrication and Economy of Metal Structures, 469–76. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-36691-8_71.
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Khuc, Tung, and F. Necati Catbas. "Computer vision-based displacement and vibration monitoring without using physical target on structures." In Bridge Design, Assessment and Monitoring, 89–100. Routledge, 2018. http://dx.doi.org/10.1201/9781351208796-8.
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Akiyama, Mitsuyoshi, Dan M. Frangopol, and Koshin Takenaka. "Reliability-based durability design and service life assessment of reinforced concrete deck slab of jetty structures." In Bridge Design, Assessment and Monitoring, 52–61. Routledge, 2018. http://dx.doi.org/10.1201/9781351208796-5.
Full textConference papers on the topic "Design and assessment of bridge structures"
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Stragys, Modestas. "Non-linear behavior of innovative steel cable-stayed bridge stiffening girder." In The 13th international scientific conference “Modern Building Materials, Structures and Techniques”. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/mbmst.2019.156.
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Until these days there are three very well-known structural forms in cable-stayed bridge construction: radial, harp and fan. These three well-known and analyzed systems ensure the stability of the cable-stayed bridges in a variety of conditions. In order to reduce the amount of materials various solutions are used. One way to reduce the cost of steel may be a new, innovative structural form. A new cable-stayed bridge structure, which requires smaller quantities of materials, is proposed in this Paper. New structural form is compared with traditional cable-stayed structures and the conclusions, which reflect the advantages of this construction, are presented. Result of the analysis is evaluation of innovative cable-stayed structure bending moments, axial forces, deflections and non-linear behavior compared with traditional cable-stayed structure under the influence of both symmetric as asymmetric loads. Technical-economical assessment is also proposed in the Paper. The Paper gives an overview of the differences between traditional and innovative design of cable-stayed bridges.
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Benham, N., C. Mundell, and C. R. Hendy. "Parametric Studies of Bridge Specific Assessment Live Loads and Implications for Assessment." In IABSE Conference, Copenhagen 2018: Engineering the Past, to Meet the Needs of the Future. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2018. http://dx.doi.org/10.2749/copenhagen.2018.154.
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A number of UK long span suspension bridges now require routine inspection, assessment and maintenance to ensure their continued durability. The UK Design Manual for Roads and Bridges (DMRB) has explicit guidance on the traffic loading for assessment lengths up to 50m, however beyond this the assumptions become conservative. In these instances, the assessment of these structures requires a Bridge Specific Assessment Live Load (BSALL) to be derived. Although a number of methodologies exist to derive BSALLs, there are several parameters that may significantly affect their results and there is little published guidance on the subject. <p> Through recent work covering the calculation of suspension bridges, Atkins have completed many parametric studies, considering different distribution methods and the relative importance of the various parameters involved. This paper discusses the above themes and outlines the advancements made by Atkins in this field, highlighting the critical parameters to consider, the advantages and limitations of the various approaches, and a recommended approach based on our findings to date.
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Azadbakht, Mohsen, and Solomon C. Yim. "Bridge Superstructure Design for Tsunamis: A State-of-the-Art Methodology for Tsunami Modeling, Load Simulation, and Structural Response Assessment." In Structures Congress 2015. Reston, VA: American Society of Civil Engineers, 2015. http://dx.doi.org/10.1061/9780784479117.030.
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Stochino, Flavio, Fausto Mistretta, Giuseppe Mancini, and Luisa Pani. "Structural assessment and retrofitting of damaged reinforced concrete water bridge." In IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.1476.
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<p>Ageing of Reinforced Concrete (RC) structures is an important problem nowadays, in particular for countries like Italy in which the main infrastructures were built 55 years ago. Carbonation and chloride penetration represent the main causes of reinforcements corrosion because they reduce the passivation of reinforcing steel in concrete.</p><p>In this paper the structural assessment of an existing RC water bridge and the following retrofitting design is presented. Built in the years between 1953 and 1961 in Sardinia (Italy), it is a 180 m long bridge with 18 spans of 10 m. It is characterized by a U-shape cross section (5.7 m width, 3.8 m height).</p><p>The structure was damaged by water and environmental action that produced concrete degradation and reinforcements corrosion. Existing material characterization and structures conditions assessment will be discussed along with the retrofitting project. The latter is characterized by a structural jacketing of the bridge piers with new concrete and reinforcements. The bridge cross-section will be also retrofitted with a complete external jacket casted with self-compacting concrete (SCC). Particular attention has been devoted to the new joints that connect the 40m long bridge sections. Indeed, they should guarantee water tightness even with the important longitudinal displacements due to structural load.</p>
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Khan, Rashid Ahmed, Aslam Faqeer Mohammad, Sarosh Hashmat Lodi, Murad Ali Shah, and Sohail Bashir. "Condition Assessment of an Aging PSC Bridge in Karachi." In IABSE Conference, Seoul 2020: Risk Intelligence of Infrastructures. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2020. http://dx.doi.org/10.2749/seoul.2020.161.
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<p>With many of the Karachi bridges that are built before the adoption of modern philosophies of design, are structurally deficient and degraded, owing to the ageing effects and non-existent maintenance. In most cases, these bridges as they approach their service lifetime are now carrying much higher volume and heavier loaded freight vehicles, which warrants continuous assessment of their safety to increased operational loads and seismicity, before deciding on their optimal management.</p><p>A pre-stressed concrete bridge (PSC) located in Karachi is investigated for structural deficiencies and possible weakening based on a three-tier approach, including Non-Destructive Evaluation (NDE) and seismic evaluation. The study results show that the overall behaviour of the bridge structure has adequate strength to meet the West Pakistan Highway Code (WPHC) [1] and American Association of State Highway and Transportation Officials (AASHTO) 2006 [2] code demands.</p>
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Loewenthal, Lucy, and David Collings. "Chelsea Bridge - The assessment of a 1937 self-anchored suspension bridge." In IABSE Symposium, Guimarães 2019: Towards a Resilient Built Environment Risk and Asset Management. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/guimaraes.2019.0392.
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<p>Chelsea Bridge is a self-anchored suspension road bridge spanning 212m over the River Thames in London, UK. It is Grade II listed and was opened in 1937. Arcadis carried out an inspection and assessment this demonstrated that Chelsea Bridge was in good condition and that it has a load carrying capacity of full 40t assessment live loading, despite having had no major intervention works since construction. The structural evaluation and assessment techniques were informed by the original calculations and publications. This information, together with the bridge’s good condition and lack of alteration, has enabled a direct comparison to be made between the design and the assessment calculations. The similarities and differences are identified between the design and assessment techniques in this paper to: firstly, determine the vehicular live loading; secondly, undertake the structural analysis; and thirdly review the factors of safety.</p>
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Cao, Wen-Jun, Wang-Sheng Liu, Chan Ghee Koh, and I. F. C. Smith. "Exploring potential benefits of bridge condition assessment in highway operations." In IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.2371.
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<p>In recent years, an increasing number of private firms are involved in public works using the funding strategy of public-private partnerships (PPPs), especially for civil infrastructure projects such as highways and bridges. In this paper, a framework is proposed to quantify the potential benefits of condition assessment in the operation phase. The updated safety condition of highway bridges is introduced as a constraint of the profit optimization problem. The framework includes the following three steps. First, structural identification is carried out to identify parameter values of the bridge involved in the highway project. Then the reserve capacity under the relevant limit state is calculated based on the requirements of bridge design codes. The last step is to investigate the effects of reserve capacity on the optimal operating profit. This framework is applied to a highway flyover project in Singapore. The optimal operating profit based on quantified reserve capacity increases relative to the case without information of reserve capacity. This significant potential economic benefit associated with bridge condition assessment in the operation phase of toll highways.</p>
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Mendoza, Carlos, José Matos, Neryvaldo Galvão, and Álvaro Viviescas. "Reliability based performance assessment of a roadway bridge under seismic actions." In IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2021. http://dx.doi.org/10.2749/christchurch.2021.0212.
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<p>External events represent the most common causes of bridge failure which could indicate distress, partial or total collapse (failure of all substantial parts of a bridge). One of the main environmental factors are earthquakes, which have a high impact on bridges due to irregularities presented in both substructure and superstructure and vulnerabilities acquired by the codes used in its design. This article presents a framework to obtain the reliability index of a bridge under seismic events, using response surface method and first order reliability method, based on random variables that affect the structure capacity (pushover analysis) and the seismic loads (peak ground acceleration). The bridge reliability of the case study is updated using visual inspection techniques. Results indicate that the vulnerable zone on the bridge is its shortest pier and the failure could occur due to high shear concentration in the hinge at the bottom of the pier.</p>
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Galvão, Neryvaldo, José Campos e Matos, Daniel V. Oliveira, and Carlos Santos. "Assessment of roadway bridges damaged by human errors using risk indicators and robustness index." In IABSE Symposium, Guimarães 2019: Towards a Resilient Built Environment Risk and Asset Management. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/guimaraes.2019.0236.
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<p>To the bridges failures that have been arising over the years, experts have pointed out as the main cause of failure, human errors, in the design, construction and operation phases. One of the main goals of this paper is the identification of the foremost causes of failure due to human errors in design and construction procedures. Therefore, a bridge failure database that includes several failure cases and a human errors survey will be used to support this line of work. After the identification of some explicit human errors that is believed to be the source of several reinforced concrete bridges failures, a selective analysis using risk indicators, namely, the probability of occurrence and consequence, is performed to choose those that might represent a higher risk for the structural safety. The outcome of five selected human errors in a specific case study is quantified using a robustness index, computed according to the variation of the structure reliability index due to the damages caused by human errors, allowing to demonstrate their impact in the structural safety. The modelling process and the finite element analysis of the structure is performed using TNO DIANA software, allowing the calculation of the reliability index of the structure damaged by different human errors. Within the COST action TU-1406, the main goal of this work is a contribution for the establishment of a roadways bridge quality control plan with higher efficiency in the reduction of bridge failures, their mortality rates and economic loss.</p>
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Vidaković, Aleksandar, and Jaroslav Halvonik. "Shear resistance of clamped deck slabs assessed using design equations and FEM analysis." In The 13th international scientific conference “Modern Building Materials, Structures and Techniques”. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/mbmst.2019.087.
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Reinforced concrete (RC) slabs without shear reinforcement are commonly used in the existing bridge structures. An ability of RC slabs to distribute the concentrated loads due to the wheel pressure in transverse direction is an important property for their verification. The aim of this paper is to investigate the effect of redistribution of shear forces and bending moments on the load carrying capacity of RC slabs subjected to concentrated loads. Two methods of the assessment are used: simplified analytical formulations and linear finite element analysis (LFEA). The obtained results are consequently compared with the test results taken from three experimental campaigns. The analyses show big differences among the results obtained from the simplified analytical methods that are based on the design equations introduced in the relevant standards. Improved methods, such as LFEA combined with analytical post-processing method, reflect the structural behaviour in a better way and provide more accurate load-bearing capacity prediction of the bridge deck slabs.
Reports on the topic "Design and assessment of bridge structures"
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Lyn, Dennis, Sayan Dey, Siddharth Saksena, and Venkatesh Merwade. Assessment of HY-8 and HEC-RAS Bridge Models for Large-Span Water-Encapsulating Structures. Purdue University, February 2019. http://dx.doi.org/10.5703/1288284316781.
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Yan, Yujie, and Jerome F. Hajjar. Automated Damage Assessment and Structural Modeling of Bridges with Visual Sensing Technology. Northeastern University, May 2021. http://dx.doi.org/10.17760/d20410114.
Full textAbstract:
Recent advances in visual sensing technology have gained much attention in the field of bridge inspection and management. Coupled with advanced robotic systems, state-of-the-art visual sensors can be used to obtain accurate documentation of bridges without the need for any special equipment or traffic closure. The captured visual sensor data can be post-processed to gather meaningful information for the bridge structures and hence to support bridge inspection and management. However, state-of-the-practice data postprocessing approaches require substantial manual operations, which can be time-consuming and expensive. The main objective of this study is to develop methods and algorithms to automate the post-processing of the visual sensor data towards the extraction of three main categories of information: 1) object information such as object identity, shapes, and spatial relationships - a novel heuristic-based method is proposed to automate the detection and recognition of main structural elements of steel girder bridges in both terrestrial and unmanned aerial vehicle (UAV)-based laser scanning data. Domain knowledge on the geometric and topological constraints of the structural elements is modeled and utilized as heuristics to guide the search as well as to reject erroneous detection results. 2) structural damage information, such as damage locations and quantities - to support the assessment of damage associated with small deformations, an advanced crack assessment method is proposed to enable automated detection and quantification of concrete cracks in critical structural elements based on UAV-based visual sensor data. In terms of damage associated with large deformations, based on the surface normal-based method proposed in Guldur et al. (2014), a new algorithm is developed to enhance the robustness of damage assessment for structural elements with curved surfaces. 3) three-dimensional volumetric models - the object information extracted from the laser scanning data is exploited to create a complete geometric representation for each structural element. In addition, mesh generation algorithms are developed to automatically convert the geometric representations into conformal all-hexahedron finite element meshes, which can be finally assembled to create a finite element model of the entire bridge. To validate the effectiveness of the developed methods and algorithms, several field data collections have been conducted to collect both the visual sensor data and the physical measurements from experimental specimens and in-service bridges. The data were collected using both terrestrial laser scanners combined with images, and laser scanners and cameras mounted to unmanned aerial vehicles.
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Stehno, Abigail, Jeffrey Melby, Shubhra Misra, Norberto Nadal-Caraballo, and Victor Gonzalez. Sabine Pass to Galveston Bay, TX Pre-construction, Engineering and Design (PED) : coastal storm surge and wave hazard assessment : report 4 – Freeport. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/41903.
Full textAbstract:
The US Army Corps of Engineers, Galveston District, is executing the Sabine Pass to Galveston Bay Coastal Storm Risk Management (CSRM) project for Brazoria, Jefferson, and Orange Counties regions. The project is currently in the Pre-construction, Engineering, and Design phase. This report documents coastal storm water level (SWL) and wave hazards for the Freeport CSRM structures. Coastal SWL and wave loading and overtopping are quantified using high-fidelity hydrodynamic modeling and stochastic simulations. The CSTORM coupled water level and wave modeling system simulated 195 synthetic tropical storms on three relative sea level change scenarios for with- and without-project meshes. Annual exceedance probability (AEP) mean values were reported for the range of 0.2 to 0.001 for peak SWL and wave height (Hm0) along with associated confidence limits. Wave period and mean wave direction associated with Hm0 were also computed. A response-based stochastic simulation approach is applied to compute AEP values for overtopping for levees and overtopping, nappe geometry and combined hydrostatic and hydrodynamic fluid pressures for floodwalls. CSRM crest design elevations are defined based on overtopping rates corresponding to incipient damage. Survivability and resilience are evaluated. A system-wide hazard level assessment was conducted to establish final recommended system-wide elevations.
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Stehno, Abigail, Jeffrey Melby, Shubhra Misra, Norberto Nadal-Caraballo, and Victor Gonzalez. Sabine Pass to Galveston Bay, TX Pre-construction, Engineering and Design (PED) : coastal storm surge and wave hazard assessment : report 2 – Port Arthur. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/41901.
Full textAbstract:
The US Army Corps of Engineers, Galveston District, is executing the Sabine Pass to Galveston Bay Coastal Storm Risk Management (CSRM) project for Brazoria, Jefferson, and Orange Counties regions. The project is currently in the Pre-construction, Engineering, and Design phase. This report documents coastal storm water level and wave hazards for the Port Arthur CSRM structures. Coastal storm water level (SWL) and wave loading and overtopping are quantified using high-fidelity hydrodynamic modeling and stochastic simulations. The CSTORM coupled water level and wave modeling system simulated 195 synthetic tropical storms on three relative sea level change scenarios for with- and without-project meshes. Annual exceedance probability (AEP) mean values were reported for the range of 0.2 to 0.001 for peak SWL and wave height (Hm0) along with associated confidence limits. Wave period and mean wave direction associated with Hm0 were also computed. A response-based stochastic simulation approach is applied to compute AEP values for overtopping for levees and overtopping, nappe geometry, and combined hydrostatic and hydrodynamic fluid pressures for floodwalls. CSRM crest design elevations are defined based on overtopping rates corresponding to incipient damage. Survivability and resilience are evaluated. A system-wide hazard level assessment was conducted to establish final recommended system-wide elevations.
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Stehno, Abigail, Jeffrey Melby, Shubhra Misra, Norberto Nadal-Caraballo, and Victor Gonzalez. Sabine Pass to Galveston Bay, TX Pre-construction, Engineering and Design (PED) : coastal storm surge and wave hazard assessment : report 3 – Orange County. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/41902.
Full textAbstract:
The US Army Corps of Engineers, Galveston District, is executing the Sabine Pass to Galveston Bay Coastal Storm Risk Management (CSRM) project for Brazoria, Jefferson, and Orange Counties regions. The project is currently in the Pre-construction, Engineering, and Design phase. This report documents coastal storm water level (SWL) and wave hazards for the Orange County CSRM structures. Coastal SWL and wave loading and overtopping are quantified using high-fidelity hydrodynamic modeling and stochastic simulations. The CSTORM coupled water level and wave modeling system simulated 195 synthetic tropical storms on three relative sea level change scenarios for with- and without-project meshes. Annual exceedance probability (AEP) mean values were reported for the range of 0.2 to 0.001 for peak SWL and wave height (Hm0) along with associated confidence limits. Wave period and mean wave direction associated with Hm0 were also computed. A response-based stochastic simulation approach is applied to compute AEP values for overtopping for levees and overtopping, nappe geometry, and combined hydrostatic and hydrodynamic fluid pressures for floodwalls. CSRM crest design elevations are defined based on overtopping rates corresponding to incipient damage. Survivability and resilience are evaluated. A system-wide hazard level assessment was conducted to establish final recommended system-wide elevations.
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Melby, Jeffrey, Thomas Massey, Abigail Stehno, Norberto Nadal-Caraballo, Shubhra Misra, and Victor Gonzalez. Sabine Pass to Galveston Bay, TX Pre-construction, Engineering and Design (PED) : coastal storm surge and wave hazard assessment : report 1 – background and approach. Engineer Research and Development Center (U.S.), September 2021. http://dx.doi.org/10.21079/11681/41820.
Full textAbstract:
The US Army Corps of Engineers, Galveston District, is executing the Sabine Pass to Galveston Bay Coastal Storm Risk Management (CSRM) project for Brazoria, Jefferson, and Orange Counties regions. The project is currently in the Pre-construction, Engineering, and Design phase. This report documents coastal storm water level and wave hazards for the Port Arthur CSRM structures. Coastal storm water level (SWL) and wave loading and overtopping are quantified using high-fidelity hydrodynamic modeling and stochastic simulations. The CSTORM coupled water level and wave modeling system simulated 195 synthetic tropical storms on three relative sea level change scenarios for with- and without-project meshes. Annual exceedance probability (AEP) mean values were reported for the range of 0.2 to 0.001 for peak SWL and wave height (Hm0) along with associated confidence limits. Wave period and mean wave direction associated with Hm0 were also computed. A response-based stochastic simulation approach is applied to compute AEP runup and overtopping for levees and overtopping, nappe geometry, and combined hydrostatic and hydrodynamic fluid pressures for floodwalls. CSRM structure crest design elevations are defined based on overtopping rates corresponding to incipient damage. Survivability and resilience are evaluated. A system-wide hazard level assessment was conducted to establish final recommended system-wide CSRM structure elevations.
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Lehtimaki, Susanna, Aisling Reidy, Kassim Nishtar, Sara Darehschori, Andrew Painter, and Nina Schwalbe. Independent Review and Investigation Mechanisms to Prevent Future Pandemics: A Proposed Way Forward. United Nations University International Institute for Global Health, April 2021. http://dx.doi.org/10.37941/rr/2021/1.
Full textAbstract:
The COVID-19 pandemic has created enormous challenges for national economies, livelihoods, and public services, including health systems. In January 2021, the World Health Organization proposed an international treaty on pandemics to strengthen the political commitment towards global pandemic preparedness, control, and response. The plan is to present a draft treaty to the World Health Assembly in May 2021. To inform the design of a support system for this treaty, we explored existing mechanisms for periodic reviews conducted either by peers or an external group as well as mechanisms for in-country investigations, conducted with or without country consent. Based on our review, we summarized key design principles requisite for review and investigation mechanisms and explain how these could be applied to pandemics preparedness, control, and response in global health. While there is no single global mechanism that could serve as a model in its own right, there is potential to combine aspects of existing mechanisms. A Universal Periodic Review design based on the model of human rights treaties with independent experts as the authorized monitoring body, if made obligatory, could support compliance with a new pandemic treaty. In terms of on-site investigations, the model by the Committee on Prevention of Torture could lend itself to treaty monitoring and outbreak investigations on short notice or unannounced. These mechanisms need to be put in place in accordance with several core interlinked design principles: compliance; accountability; independence; transparency and data sharing; speed; emphasis on capabilities; and incentives. The World Health Organization can incentivize and complement these efforts. It has an essential role in providing countries with technical support and tools to strengthen emergency preparedness and response capacities, including technical support for creating surveillance structures, integrating non-traditional data sources, creating data governance and data sharing standards, and conducting regular monitoring and assessment of preparedness and response capacities.