Commissioned for this report is Ramboll, Bridge and Tunnel Unit in Stockholm. The idea throughout the work has been to primarily help bridge designers compiling advice and instructions on how fatigue verification for railway bridges in reinforced concrete shall be performed under the new rules, the Eurocodes. After the introduction of the Eurocodes in 2011 has major problems emerged among designers around Sweden. In some areas, it differs in the calculation rules compared with rules from the Swedish Transport Administration and the National Board of Housing, Building and Planning calculation. Fatigue verification is one area where the new calculation rules are different from the past. A large part of the report has been to interpret and find the relevant information in the Eurocodes concerning fatigue. When questions or doubts have surfaced, this has been discussed with Elisabeth Helsing at the Swedish Transport Administration and bridge designers at Ramboll. The result is a report where the structure is organized in the way that the bridge designers can move from cover to cover and realize that fatigue verification in reality follows the same order as the report's sections. The issues have been resolved and reported regularly through the report with complementary findings as a result. Some of the greatest advances in the report are the load combinations to be used for the method for fatigue verification, how the dynamic factor and the magnification factor should be used and how the trainloads to be designed for each method for fatigue verification.

<p>Föreliggande avhandling omfattar en fallstudie av utmattningsrisken för järnvägsbroarna mellan Stockholm Central och Söder Mälarstrand. Ett stort antal utmattningssprickor i broarna över Söderström och Söder Mälarstrand har sedan länge varit kända. I samband med en bärighetsutredning av sträckan har ett stort antal anslutningspunkter i samtliga broar identifierats som kritiska avseende utmattningsrisk. Sträckan är den mest trafikerade i Sverige och de förenklade beräkningsmetoder som anges i Banverkets föreskrift för bärighetsberäkningar är i vissa fall inte tillämpliga.</p><p>De formella bärighetsberäkningarna har visat på flerfaldiga överskridanden i utnyttjandegrad gällande utmattning. I de punkter som beräkningarna visar störst risk för utmattning har inga sprickor påträffats, trots omfattande förbandsbesiktningar. Beräkningarna baseras på typiserade spänningskollektiv och givet antal spännings­växlingar, oberoende av den aktuella trafikmängden. Enligt bärighetsnormen ges möjlighet att beakta den verkliga trafikmängden baserat på historiskt bruttotonnage och typiserade trafiklaster. Dessa beräkningar har utförts och visar på ännu större risk för utmattning, jämfört med den förenklade metoden. I syfte att på ett ännu mer nyanserat sätt uppskatta utmattningsrisken har en metod använts, baserat på uppskattning av den faktiska trafikmängden och dess fördelningar. Beräkningarna baseras på trafikdata tillgänglig från Banverket. Metoden är tillämplig på andra järnvägsbroar på andra sträckor.</p><p>Utöver teoretiska beräkningar har töjningsmätningar utförts. Under 2006 utförde dåvarande Carl Bro AB töjningsmätningar på bro över Söder Mälarstrand och viadukt söder om Söder Mälarstrand, avseende några enskilda tågöverfarter. Under 2008 utförde KTH Brobyggnad omfattande töjningsmätningar på bro över Söderström, avseende all trafik under en månads tid.</p> / <p>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.</p><p>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.</p><p>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.</p>

Föreliggande avhandling omfattar en fallstudie av utmattningsrisken för järnvägsbroarna mellan Stockholm Central och Söder Mälarstrand. Ett stort antal utmattningssprickor i broarna över Söderström och Söder Mälarstrand har sedan länge varit kända. I samband med en bärighetsutredning av sträckan har ett stort antal anslutningspunkter i samtliga broar identifierats som kritiska avseende utmattningsrisk. Sträckan är den mest trafikerade i Sverige och de förenklade beräkningsmetoder som anges i Banverkets föreskrift för bärighetsberäkningar är i vissa fall inte tillämpliga. De formella bärighetsberäkningarna har visat på flerfaldiga överskridanden i utnyttjandegrad gällande utmattning. I de punkter som beräkningarna visar störst risk för utmattning har inga sprickor påträffats, trots omfattande förbandsbesiktningar. Beräkningarna baseras på typiserade spänningskollektiv och givet antal spännings­växlingar, oberoende av den aktuella trafikmängden. Enligt bärighetsnormen ges möjlighet att beakta den verkliga trafikmängden baserat på historiskt bruttotonnage och typiserade trafiklaster. Dessa beräkningar har utförts och visar på ännu större risk för utmattning, jämfört med den förenklade metoden. I syfte att på ett ännu mer nyanserat sätt uppskatta utmattningsrisken har en metod använts, baserat på uppskattning av den faktiska trafikmängden och dess fördelningar. Beräkningarna baseras på trafikdata tillgänglig från Banverket. Metoden är tillämplig på andra järnvägsbroar på andra sträckor. Utöver teoretiska beräkningar har töjningsmätningar utförts. Under 2006 utförde dåvarande Carl Bro AB töjningsmätningar på bro över Söder Mälarstrand och viadukt söder om Söder Mälarstrand, avseende några enskilda tågöverfarter. Under 2008 utförde KTH Brobyggnad omfattande töjningsmätningar på bro över Söderström, avseende all trafik under en månads tid. / 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.

I Sverige har vi en trend med ökande axellaster på våra järnvägar, där den mest utsatta sträckan är Malmbanan mellan Luleå och Riksgränsen. Ökade axellaster leder i regel även till ett ökat slitage och nedbrytning av de ingående konstruktionsdelarna i anläggningen. För stålbroar innebär högre axellaster att utmattningsspänningarna ökar, med följden att den teoretiska utmattningslivslängden minskar. Vid byggandet av en ny bro med ett bärverk i stål kan utmattningsverifieringen antingen utföras med den enklare λ-metoden eller den mer omfattande Palmgren-Miners delskadehypotes. I detta examensarbete har det studerats hur valet av modell påverkar resultatet av utmattningsverifieringen. Fokus har legat på en fallstudie av järnvägsbron över Rörströmsälven där utmattningen kontrollerats med Palmgren-Miners delskadehypotes och λ-metoden. Bron har kontrollerats för både övrig järnvägstrafik samt för tung massgodstrafik, som Malmbanan, för att se hur metoderna skiljer sig åt vid olika trafikförutsättningar.   Den faktor som påverkar utmattningen mest är ökad axellast på grund av det icke linjära förhållandet mellan den förväntande utmattningslivslängden och spänningsvidden i stålet. Antalet cykler har också en stor påverkan på utmattningslivslängden men det är inte lika starkt påverkande på grund av ett linjärt förhållande mellan utmattningslivslängden och antalet cykler. En skillnad mellan den enklare λ-metoden och Palmgren-Miners delskadehypotes är att den bygger på en enda trafiklastmodell (LM71), samt att metoden bygger på λ-faktorer som beaktar spännvidd, trafikmängd, livslängd samt trafik på flera spår. Den mer omfattande Palmgren-Miners delskadehypotes bygger i stället på delskador som orsakas av varje enskild tågtyp som passerar bron under dess livslängd. De olika tågtyperna definieras enligt SS-EN 1991–2 och trafiksammansättningarna med tillhörande trafikmängd definieras av Trafikverket. Denna metod kan därför anpassas mer till den faktiska trafiken som bron utsätts för under sin livslängd. Resultatet från detta examensarbete indikerar på att den enklare λ-metoden inte är tillräckligt konservativ för att tillämpa i alla situationer. Där broar dimensioneras för övrig trafik kan λ-metoden tillämpas på säker sida, medan för broar som dimensioneras för tung massgodstrafik så visar det sig att λ-metoden inte är tillräckligt konservativ och därmed på osäker sida, i jämförelse med en beräkning av delskadan. Även om λ-metoden förefaller vara tillräckligt konservativ för broar som dimensioneras för övrig trafik så finns det fördelar med att tillämpa den mer omfattande Palmgren-Miners delskadehypotes för att erhålla en mer materialeffektiv konstruktion, vilket är en stor fördel vid stålkonstruktioner då stålindustrin står för 7 % av världens koldioxidutsläpp. Resultaten som påvisas i denna rapport bygger på fallstudien av bron över Rörströmsälven. För att dra mer konkreta slutsatser behöver fler brotyper med olika spännvidder och flerspannsbroar studeras där även andra kritiska detaljer kan kontrolleras. / In Sweden, we have a trend of increasing axle loads on our railways, with the most vulnerable stretch being the Malmbanan between Luleå and Riksgränsen. Increased axle loads generally lead to increased wear and degradation of the constituent parts of the infrastructure. For steel bridges, higher axle loads result in increased fatigue stresses, leading to a decrease in the theoretical fatigue life. When constructing a new bridge with a steel structure, fatigue verification can be carried out using either the simpler λ-coefficient method or the more comprehensive Palmgren-Miners cumulative damage method. This thesis examines how the choice of model affects the results of fatigue verification, focusing on a case study of the railway bridge over Rörströmsälven, where fatigue has been assessed using both the Palmgren-Miners cumulative damage method and the λ-coefficient method. The bridge has been assessed for both regular railway traffic and heavy freight traffic like Malmbanan, to observe the differences between the methods under different traffic conditions. The factor that most affects fatigue is increased axle load due to the non-linear relationship between the expected fatigue life and the stress range in the steel. The number of cycles also has a significant impact on fatigue life, although it is not as pronounced due to a linear relationship between fatigue life and the number of cycles. A difference between the simpler λ-coefficient method and Palmgren-Miners cumulative damage method is that the former is based on a single traffic load model (LM71) and λ-factors that consider span length, traffic volume, service life, and traffic on multiple tracks. The more comprehensive Palmgren-Miners cumulative damage method is on the other hand based on damages caused by each individual train type passing over the bridge during its service life. The different train types are defined according to SS-EN 1991–2, and the traffic compositions with corresponding traffic volumes are defined by the Swedish Transport Administration (Trafikverket). Therefore, this method can be better adapted to the actual traffic the bridge is exposed to during its service life. The results of this thesis indicate that the simpler λ-coefficient method is not conservative enough to apply in all situations. While the λ-coefficient method can be applied safely when bridges are designed for regular traffic, it is not conservative enough for bridges designed for heavy freight traffic, compared to a calculation of the cumulative damage. Even though the λ-coefficient method appears to be conservative enough for bridges designed for regular traffic, there are advantages to applying the more comprehensive Palmgren-Miners cumulative damage method, as it can lead to a more material-efficient design, which is a significant advantage for steel structures, considering that the steel industry accounts for 7% of the world's carbon dioxide emissions. The results presented in this report are based on the case study of the bridge over Rörströmsälven. To draw more general conclusions, more types of bridges with different span lengths and multi-span bridges need to be studied, where other critical details also can be assessed.

In 1911 Valfrid Palmgren founded the Children&apos;s Library of Stockholm, the very first in Sweden.She was a well-educated woman, who believed in social and educational equality for all.During a journey to the USA in 1907, she was deeply impressed by the public libraries, andshe put many of the public library ideas to use in the Children&apos;s Library of Stockholm. Palmgrenstrongly opposed to the Swedish libraries not allowing admission to children, since shefirmly believed that educating the people had to start with the children.Other reasons for opening a children&apos;s library were to give children an alternative to roamingthe streets, to give children a quiet place to read, to give an alternative to the cheap trashliterature that flooded the market and to teach the young ones how to extract information frombooks. Of great importance was that the library should be equal to all classes in society.In 1927 the children&apos;s library was taken over by the new public library of Stockholm.

This thesis investigates the early field of library knowledge in Sweden between 1912 and 1939 (circa) through the lens ofFoucault’s archaelogy using a number of official documents (reports, bills, and statutes) as well as a number of articlesand speeches published in the journal Biblioteksbladet (founded 1916). It seeks to answer the question of how it becamepossible to form a field of knowledge, which external relations structured and enabled the field to exist, and which internalrelations of power and authority made it possible for librarians, state officials, ministers of education, and other experts toagree and disagree on the proper management of public libraries during the period.

In this thesis, fatigue life of a cantilever aluminum plate with a side notch under certain loading conditions is analyzed. Results of experimental stress analysis of the cantilever aluminum plate by using a uniaxial strain gage are presented. The strain gage is glued on a critical point at the specimen where stress concentration exists. Strain measurement is performed on the base-excited cantilever beam under random vibration test in order to examine the life profile simulation. The fatigue analysis of the test specimen is carried out in both time and frequency domains. Rainflow cycle counting in time domain is examined by taking the time history of load as an input. Number of cycles is determined from the time history. In frequency domain analysis, power spectral density function estimates of normal stress are obtained from the acquired strain data sampled at 1000 Hz. The moments of the power spectral density estimates are used to find the probability density function estimate from Dirlik&rsquo / s empirical expression. After the total number of cycles in both time and frequency domain approaches are found, Palmgren-Miner rule, cumulative damage theory, is used to estimate the fatigue life. Results of fatigue life estimation study in both domains are comparatively evaluated. Frequency domain approach is found to provide a marginally safer prediction tool in this study.

The thesis deals with the role and development of Public libraries with a focus on the political debate between 1899 and 1912. Public libraries today have a role as a socially important institution and are thus an important part of our society. In order to understand and gain clarity about today's Public library debate and the Public libraries' institutional role and legitimacy, the debate that prompted the development of Public libraries around the turn of the century in 1900 needs to be examined and elucidated. The thesis will deal with the background to the political library debate that took place between 1899 and 1912, how the arguments put forward for the library's development and role in society were and what parallels can be drawn to a contemporary context. The empiric consists mainly of political documents from the Parliament debate and these are analyzed on the basis of an institutional theoretical approach through a qualitative content analysis. Valfrid Palmgren's investigation and report, which was presented in 1911-1912, became important for the development of the Public library and may thus conclude the historical context. The result of the thesis shows a Public library development that follows the prevailing social development in a society where the people's voices through popular movement work, popular education and commitment worked towards democratic goals. The Public libraries came to be important for both the development of that time and have so also today through their today institutional role in society.

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