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  • 151.
    Andersson, Anna
    et al.
    Mälardalen University, School of Business, Society and Engineering.
    Carlson, Eva-Sara
    Mälardalen University, School of Business, Society and Engineering.
    Structures in underground facilities: Analysis of a Concrete Column’s Capacity to Withstand Extraordinary Fire Loads2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The report present a Master of Science in engineering work carried out at Mälardalen’s University, made this work within the research project METRO. The work is a part of the research project METRO. The focus of the METRO project is on the protection of underground rail mass transport systems e.g. tunnels and subways stations. The aim with this work was to determine if a concrete column placed close to the tracks at a subway station can withstand the effect and temperature of a fire in a burning train comparable to the effects and temperatures that showed at the full scale test carried out within the METRO project. A literature review was made previous to the following case study. The results from this show that the column is negligible affected by the fire.

  • 152.
    Andersson, Elin
    et al.
    University West, Department of Engineering Science.
    Ahl, Viktoria
    University West, Department of Engineering Science.
    Täktverksamhet: En undersökning av beslut om avgifter och nedsättning2012Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien var att utreda huruvida det råder en konsekvent hantering av tillsynsavgifter och ifall beslut om nedsättning tas på lika grunder. Tanken var att rapporten skulle kunna påvisa om verkligheten avspeglar lagstiftningen.

    Grunden till denna studie är frågeställningarna;

    1. Hur beslutar tillsynsmyndigheter om tillsynsavgifter?

    2. I vilken utsträckning beviljar tillsynsmyndigheter nedsättning av tillsynsavgiften?

    3. I vilken utsträckning begär verksamhetsutövare nedsättning av tillsynsavgiften?

    Begreppet täkt definieras som arbetsföretag vilket primärt syftar till att nyttiggöra det uttagna materialet. Detta sker antingen genom direktförsäljning eller i övrig verksamhet inom det egna företaget. Arbetet handlar endast om tillståndspliktiga täkter och i Sverige finns det omkring 2300 sådana igång. Tillsynsavgiften för täkterna ligger på omkring 800 kronor per timme och i snitt läggs det enligt våra intervjuer tio timmar tillsynstid per täkt och år. Det sammanlagda beloppet på tillsynskostnader i Sverige ligger således på drygt arton miljoner kronor.

    Arbetet inleds med en teoridel där läsaren ges möjlighet att få en djupare förståelse för täkter, tillsynsavgifter, nedsättning och de lagrum som skall följas i samband med detta. Teorin grundas på litteraturstudier och samtal med sakkunniga. Följt av teorin kommer en undersökning som valdes att utföras genom intervjuer med ett visst antal kommuner, Länsstyrelser och verksamhetsutövare. Sammanställningen av intervjuerna blev grunden för det avslutande resultatet och de slutsatser som kunde tas av undersökningen.

    Resultatet av arbetet visar på att tillsynsmyndigheter fattar beslut om tillsynsavgifter och nedsättning på olika sätt och grunder. För att få en mer likvärdig hantering av frågorna skulle en tydligare och mer konkret lagstiftning behöva arbetas fram. Vi kunde också fastslå att Naturvårdsverket som har en tillsynsvägledande roll i sammanhanget inte verkar nå ut till de tillsynsansvariga då de flesta av dem inte vet om att Naturvårdverket tillhandahåller detta stöd. Det är många frågor som väcks efter att ha fullbordat denna studie och listan på förslag till framtida arbete kan därmed göras lång

  • 153.
    Andersson, G.
    Luleå tekniska universitet.
    Creep experiments on powder1983In: Scandinavian journal of metallurgy, ISSN 0371-0459, E-ISSN 1600-0692, Vol. 12, no 6, p. 312-314Article in journal (Refereed)
    Abstract [en]

    The change in strain during constant loading in die, isostatic and triaxial compaction has been studied for tungsten carbide powder. The creep effect change is largest for isostatic loose powder compaction whereas the slightly precompacted specimens (20 MPa) show less strain change. The creep effect gives modest contributions to the total strain for reasonable times. The highest pressure at which the effect has been recorded is 200 MPa

  • 154.
    Andersson, Hanna
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Business Administration.
    Tillförlitlig försörjningskedja: En fallstudie på Saabs projektprocess2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 155.
    Andersson, Ina
    Blekinge Institute of Technology, Faculty of Engineering, Department of Spatial Planning.
    Garden cities of today: En applicering av Garden cities-idealet i en nutida svensk kontext2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Detta arbete undersöker vad som kan sägas utgöra kärnan i Garden cities-idealet utifrån Ebenezer Howards definition och Johan Rådbergs tolkning av Howard. Vidare undersöker arbetet hur idealet kan tolkas, förstås och appliceras i en nutida svensk kontext. De gestaltningsprinciper som kan sägas vara bärande för idealet används som utgångspunkt för utformandet av en illustrationsplan över Varvsstaden i Malmö. Därmed exemplifieras hur idealet kan förstås konkret i planeringssammanhang och vilka effekter som följer på ett genomförande av idealet i en central stadsdel i en storstad.

    För den teoretiska delen av arbetet används en innehållsanalys och de gestaltningsprinciper som utläses som bärande för Garden cities-idealet skisseras sedan fram i syfte att skapa "visuella verktyg" för den illustrationsplan som arbetas fram.

    Arbetet visar att det är fullt möjligt att utforma en central stadsdel i enlighet med Garden cities-idealet och uppnå ett relativt högt exploateringstal som resultat.  

  • 156.
    Andersson, Johanna
    et al.
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Simu, Malin
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Underhåll av levande väggar: Möjligheter och utmaningar i ett svenskt urbant klimat2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose: A slow development of living walls in Sweden is partly due to lack of experience and knowledge in the construction industry. Former studies point at challenges of adapting the technique in a Swedish climate and the importance of planning, knowledge and cooperation for the maintenance. The objective of the study is to analyse a sustainable maintenance by technique and maintenance planning of the system living walls in order to answer these challenges.  

    Method: The study is based on a qualitative approach where the methods are document analysis, interview and observation. Document analysis gives a status report of the implemented living walls in Sweden and introduces strategies for maintenance planning. Interview with relevant participants contributes with experiences concerning technique, maintenance and maintenance planning. Observation confirms the information about the technique.

    Findings: The study shows that none of the observed solutions can be considered completely sustainable, though they do have some sustainable qualities. Living walls have strong social and ecological benefits, where the vegetation contributes to increase ecosystem services in urban environment. A less use of resources is necessary for a sustainable technique where the use of stormwater, local resistant plants, lasting construction and recycled components promotes a sustainable environment and economy. The felt system is simpler in its design while the modular system is more flexible. A common objective among the observed projects is to create a maintenance-free solution as possible. Acceptance for resting plants during winter can lower the demands of the maintenance. Technical monitoring facilitates the maintenance but the manual handling of living walls is crucial. The frequency of the maintenance varies from each project where the client’s choice, placement of the wall, type of solution, size, plant choice and season affect. Therefore, it is important with planning and constantly evaluating a walls needs. The majority of the observed projects do not have a maintenance plan but the study shows success by a common objective, site analysis, goal-oriented maintenance plan and experience feedback.

    Implications: The conclusion of the study is that the technique of living walls needs to be evolved to leave a smaller footprint on the environment and the economy. The development is towards a maintenance-free solution but the manual handling can not be replaced by advanced technique. Every projects individual conditions demands thorough planning and continuous evaluation of the wall.

    Limitations: The study discuss living walls in the Swedish urban climate, where the result is based on experiences from projects developed in the southern part of Sweden. Other geographical placement causes different conditions for technique and maintenance. General assumptions can be made concerning the maintenance planning. More interviews with maintenance staff can contribute with other aspects to the analysis.

  • 157.
    Andersson, Lena
    Luleå tekniska universitet.
    Resource constrained mine project scheduling using critical path method1992Doctoral thesis, monograph (Other academic)
  • 158.
    Andersson, Linda
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Hedlund, Johanna
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management, Land management, GIS.
    Trivsam boendemiljö för studenter: En gestaltningsstudie utifrån studenters åsikter för ett trivsamt boende2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The physical environment is a very important component for human health.  A well-functioning site enables people to recreation and social life. People who spend a lot of time outdoor are also experiencing less stress. If people doesn’t give opportunity to influence the spatial planning process there is a risk of negative attitudes and discomfort. This can create a mental illness. This study deals with how students feel about their physical environment and how they want it to be designed. The study is aimed at students who live in one of the three different student areas in Gävle: Kungsbäck, Campus Sätra and Midgård. The study is based on three methods. These were: a questionnaire, an observation study, and a physical design study in 3D.

     

    The observations showed significant problems with the site design as only movement, who take into necessary but significant activity account. The observations showed a clear lack of both elective and social activities, both of which are important for a well-functioning place. The survey showed dissatisfaction about the site design among the students. Through this study, students were given an opportunity to share their wishes about the site's future design. The proposals were designed in 3D. Three different proposals were developed: a zero option, an economical option, and an expensive option. The zero option indicates a probable development of the area if no action takes place. The economical option indicates a solution that focus on economical sustainability. The expensive option has the highest costs both in construction and maintenance. The evaluation showed that the students liked the economical proposal option most.

     

    The result showed the importance of student participation in the planning process. Student comments through the survey and evaluation, indicated that: trees, venues, water, grass and lighting should be included in future planning frameworks for student housing.

  • 159.
    Andersson, Lovisa
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Analys av Skiftingehus skolgårds fysiska miljö ur ett trygghetsperspektiv2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 160.
    Andersson, Lovisa
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Planera för barn i förtätad stad: En studie av hur barnvänliga utemiljöer för skolor och förskolor kan skapas i samband med stadsförtätning i Eskilstuna kommun2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    As a result of a growing population and negative climate impact, today’s planning trend in Sweden is going towards densification which means that cities are being developed by concentrating new buildings on already exploited land. Even though densification is linked to sustainability this strategy has resulted in the exclusion of significant places for children’s outdoor play, such as school and preschool playgrounds. At the same time, children are a quite powerless social group that constitute the future of society and thus knowledge of their perspectives is necessary in urban planning. Therefore, the purpose of this study is to contribute to an increased understanding of how the child perspective, the perception of a child’s best, can be applied in relation to densification of the city in the municipal community planning. In the study the child perspective is defined by examining how a municipality can create child-friendly school and preschool outdoor environments.

    This study applies a qualitative approach through a case study of the municipality of Eskilstuna. By conducting interviews and a documentary study, data regarding the municipality’s work with school and preschool outdoor environments was generated. In order to gain an understanding of the conditions for municipal community planning, legislation as well as government and municipal documents were studied. A literate review was also conducted with the aim of studying previous work on the child perspective, the child impact assessment, the child-friendly outdoor environment and collaborative planning. Together with data collected from expert interviews this constitutes the study’s theoretical framework that in turn formed the basis for the following discussion.

    The results prove that child-friendly outdoor environments for schools and preschools comprise several factors that promote children’s development: room for outdoor play, reduced traffic, green and natural environments, variation and challenges. Among these, room for outdoor play, the size of the school or preschool playground, is the fundamental factor.

    The study also shows that school and preschool outdoor environments are a matter that often conflicts with other challenges that the municipal community planning has to deal with. In the municipality of Eskilstuna there is an ambition to create child-friendly outdoor environments for schools and preschools. However, the lack of available places as well as strategies and guidelines makes this difficult in practice. In order to create child-friendly outdoor environments for schools and preschools the results indicate the importance of using a collaborative approach through cooperation and mutual understanding between different actors. Also, it is stated that children’s needs should be highlighted in an early stage of the process to ensure room for school and preschool playgrounds in the dense city.

  • 161.
    Andersson, Magnus
    Blekinge Institute of Technology, Faculty of Engineering, Department of Spatial Planning.
    Östra stranden - En ny stadsdel i den historiska staden Sölvesborg: (Alternativt förslag till exploatering av planområdet Ljungaviken)2015Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Arbetet handlar om en stadsdels exploatering i förhållande till staden som den skiljs från genom ett vattenrum. Stadsdelens placering gör att det är ett avstånd till stadskärnan där alla funktioner såsom handel, service, kommunikationer, nöjen och restauranger med mera finns.

    Regionförstoringen ställer krav på mindre orter och småstäder när avstånd mäts i tid istället för kilometer, samtidigt som kraven på attraktiva boende- och livsmiljöer ständigt ökar i konkurrensen om nya invånare. Förhållandet mellan stad och land är en faktor som spelar stor roll i utvecklingen av de städer och orter som inte är dominerande i regionen.

    Sölvesborg är en småstad med medeltida rötter i Blekinge län som har haft en stor nedgång i sitt näringsliv när den stora arbetsplatsen på orten lade ner under 1980-talet. Sölvesborgs kommun ligger i en expansiv region med stora arbetsgivare i de kringliggande kommunerna vilket har lett till att stora delar av befolkningen pendlar ut ur kommunen för att arbeta. Staden är en trädgårdsstad, som ligger på Sölvesborgsvikens västra sida, som lockar med ett attraktivt boende med närhet till både skog och skärgård. Sölvesborg har goda kommunikationer och flera större städer i närheten.

    För att kunna locka till sig flera invånare har beslut fattats att ett område på den östra sidan av Sölvesborgsviken exploateras. Det innebär att den historiskt sett obebyggda delen av viken skall bli en del av staden. Kommunen har upprättat en detaljplan för ett bostadsområde som har döpts till Ljungaviken och förbinds till staden med en gång- och cykelbro över vattenrummet.

    Jag har valt att analysera kommunens planförslag med hjälp av en ortsanalys som innehöll delar som geografi, karaktär, historia, funktioner, trafikstruktur, bebyggelsestruktur med mera samt en SWOT-analys gav sedan ett antal slutsatser som har legat till grund för mitt planförslag för stadsdelen.

    I planförslaget har det förts ett resonemang om förhållandet mellan stad och land, samt husr stadsdelen kan knyta an till den befintliga bebyggelsen så att det inte skapas barriärer annat än dde geografiska som redan finns. Vilken karaktär stadsdelen skall ha är en annan grundläggande fråga som behövde besvaras. Likaså hur stadsdelen skall möta sina omgivningar och de andra bebyggelseområdena i som finns i dess närhet har lett till resonemang om både strukturen på bebyggelsen och  grönområdena. De slutsatser som ortsanalysen avslöjade gav mig förutsättningar att utveckla stadsdelen i en annan riktning än vad kommunen har gjort vilket innebär att jag har skapat en stadsdel som har fler funktioner än vad som detaljplanen medger. Likaså har planförslaget en stadsmässighet och en koppling till omgivningarna som saknas i kommunens förslag.

    Jag hoppas att detta arbetet skall ses som ett diskussionsunderlag för hur stadsdelar i perifera lägen skall utvecklas.

  • 162.
    Andersson, Oskar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Seppälä, Max
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Verification of the response of a concrete arch dam subjected to seasonal temperature variations2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Many dams existing today were constructed around fifty years ago. Condition monitoring is essential for maintaining high safety and determining the current level of safety and stability for these dams. There is a need for new monitoring techniques and finite element coupled monitoring could be one of these techniques. A concrete arch dam located in Sweden is modelled and calibrated with respect to concrete temperature measurements. The temperature distribution is then defined as a prescribed strain in a structural mechanical model in which a parametric study is performed. The results from the parametric study are compared to measurements of the crest deformation and a combination of parameters is found giving the lowest difference between measurements and model results for the mid-section. The results show that the finite element model can be used to predict the behavior of the dam with acceptable deviation. The parametric study indicates that the reference temperature of the concrete has little effect on the amplitude of the deformation and that the governing factor is the coefficient of thermal expansion.

  • 163.
    Andersson, Petra
    et al.
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Wikman, Johan
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Arvidson, Magnus
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Larsson, Fredrik
    RISE - Research Institutes of Sweden, Safety and Transport, Electronics.
    Willstrand, Ola
    RISE - Research Institutes of Sweden, Safety and Transport, Safety.
    Safe introduction of battery propulsion at sea2017Report (Other academic)
    Abstract [en]

    Electric propulsion using batteries as energy storage has the potential to significantly reduce emissions from shipping and thus the environmental impact. The battery type that is currently on the top of the agenda to be used for ship propulsion applications is Li-ion batteries. Li-ion batteries pose different safety issues than e.g. other propulsion technologies and other batteries such as lead-acid batteries. It is essential that the safety level on board, including fire safety, is maintained, when introducing electric propulsion with energy storage in batteries. This report discusses the different regulations and guidelines available today for fire safety of batteries on board in relation to current knowledge about Li-ion batteries. Also fire safety measures available on board ships today and their applicability for Li-ion batteries is discussed, as well as the different test methods available and their applicability. A workshop gathering different stakeholders from Sweden, Norway and Finland identified fire safety as the main challenge for the introduction of battery propulsion at sea. The workshop concluded that future work is desired in order to increase knowledge and to develop publicly available strategies, training and designs.

  • 164.
    Andersson, Roy
    et al.
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Månsson, Bo
    Högskolan i Borås, Institutionen Ingenjörshögskolan.
    Yar Hamidi, Daniel
    Högskolan i Borås, Institutionen Handels- och IT-högskolan.
    Resilience in the supply and demand chain a new management strategy2012Conference paper (Other academic)
    Abstract [en]

    The length and complexity of the supply chain tend to increase, rather than diminish, thereby making the supply chain riskier and less predictable and, hence, more vulnerable. At the same time, customers are becoming increasingly demanding. The challenge to businesses today is to create a resilient supply chain in order to manage and mitigate risk and vulnerability. The purpose of this paper is to describe the use methods and tolls from quality and logistics can improve supply chain resilience. There are five principles that characterise supply chain resilience: risk management culture, agility, design-and innovation-led organisations, collaboration and spreading and anchoring of the vision, goal, values and methods. Using a combined quality management philosophy, the speed of process could be increased, and the responsiveness and flexibility could be improved, which means quicker response to changes. It has also been indicated that a combined quality management philosophy improves the companies’ resilience, due to their increased agility and strengthened ability to handle variability and risk management. Quality management tools can be very effective in the companies’ efforts to control supply chain risk and to identify risk sources of variation, even outside the focal company.

  • 165.
    Andersson, Roy
    et al.
    University of Borås, School of Engineering.
    Månsson, Bo
    University of Borås, School of Engineering.
    Yar Hamidi, Daniel
    University of Borås, School of Business and IT.
    Resilience in the supply and demand chain a new management strategy2012Conference paper (Other academic)
    Abstract [en]

    The length and complexity of the supply chain tend to increase, rather than diminish, thereby making the supply chain riskier and less predictable and, hence, more vulnerable. At the same time, customers are becoming increasingly demanding. The challenge to businesses today is to create a resilient supply chain in order to manage and mitigate risk and vulnerability. The purpose of this paper is to describe the use methods and tolls from quality and logistics can improve supply chain resilience. There are five principles that characterise supply chain resilience: risk management culture, agility, design-and innovation-led organisations, collaboration and spreading and anchoring of the vision, goal, values and methods. Using a combined quality management philosophy, the speed of process could be increased, and the responsiveness and flexibility could be improved, which means quicker response to changes. It has also been indicated that a combined quality management philosophy improves the companies’ resilience, due to their increased agility and strengthened ability to handle variability and risk management. Quality management tools can be very effective in the companies’ efforts to control supply chain risk and to identify risk sources of variation, even outside the focal company.

  • 166.
    Andersson Schwarz, Jonas
    Södertörn University, School of Culture and Education, Media and Communication Studies.
    Platform Logic: An Interdisciplinary Approach to the Platform-Based Economy2017In: Policy & Internet, ISSN 1944-2866, E-ISSN 1944-2866, Vol. 9, no 4, p. 374-394Article in journal (Refereed)
    Abstract [en]

    Digital platforms are not just software-based media, they are governing systems that control, interact, and accumulate. They also solidify markets; that is, social networks of exchange that do not necessarily leave data traces, into infrastructure, that is, material arrangements of traceable activity. This article examines the forms of domination found in this digital platform model, and corrects some existing simplistic theoretical conclusions about digital platforms. It first provides a schematic overview of digital infrastructures of governance, and the attendant systemic mechanics they engender. It then argues that we need a more syncretic, interdisciplinary approach to the platform-based economy. The shifting emphases of different academic disciplines in relation to digital platforms are only partially grounded in their different normative biases; they can also be attributed to use of different disciplinary lenses. The field of information systems management and design studies is chiefly concerned with direct, technical interplatform affordances and connections, and with providing observations of certain systemic attributes of digital platforms. Critical political economy, by contrast, mainly considers the emerging transnational, geopolitical formations of platform capitalism. The interplay between these different systemic mechanics is summarized and presented here in the concept of "platform logic."

  • 167.
    Andersson, Sebastian
    Mid Sweden University, Faculty of Science, Technology and Media, Department of Ecotechnology and Sustainable Building Engineering.
    Varmformade eller kallformade konstruktionsrör ur ett lönsamhetsperspektiv: Undersökning av ekonomisk differens i valet mellan VKR och KKR2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sweden, hot formed rectangular hollow sections (HFRHS) can be 15-23 % more expensive than cold formed rectangular hollow sections (CFRHS) of the same section size. Although the price on CFRHS is lower, estimations reveals that   - from the total use of HFRHS and CFRHS in Swedish steel buildings - CFRHS is only utilized by less than 5 % compared to 95 % HFRHS. This study began by examining the differences between these two types of steel. The price difference between the two processed metal types was then calculated when both of them were subjected to a centric compressive force under the same conditions. The purpose was to compare prices and find out which one is the most economically feasible, offering a more profitable choice between HFRHS or CFRHS.

    The design buckling resistance of all the section sizes in Tibnor kon­­struktions­tabeller was calculated for every possible combination out of ten different lengths between 1 m and 10 m, ten different loadings between 100 kN and 1000 kN and two different support conditions being pinned at both ends and fixed at both ends. The sections sizes of CFRHS and HFRHS that withstood the loading and held the lowest prices were compared by calculating the price difference as per­centage increment or decrement between the two types of hollow sections.

    In 80 % of the cases, when pinned at both ends, CFRHS showed to be the most economically feasible alternative. When fixed at both ends the same number was 86 %. The average price difference was 10-11 %, showing an absolute deviation of approximately 8‑12 %.

    These findings conclude that using only CFRHS can result in savings of 10‑11 % from reduced costs of steel, compared to only using HFRHS. From the observed variation of the price differences another conclusion is drawn that there aren’t any tendencies showing HFRHS or CFRHS to be more economically feasible than the other in a specific interval of length or loading.

    The recommendation is to optimize and use the type of steel that is the most economically feasible under the current circumstances. If an optimization isn’t possible then the recommendation is to use CFRHS.

  • 168.
    Andrén, Anna
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Degradation of rock and shotcrete due to ice pressure and frost shattering2009Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In recent years the Swedish Rail Administration has observed an increased incidence of shotcrete and rock fall-outs in its tunnels, for which reason it has initiated several research projects, of which the present project entitled "Degradation of rock and shotcrete due to ice pressure and frost shattering" is one. The aim of this licentiate project was to bring together experience and information relating to ice formation and the effect of ice pressure on fault zones, cracks and, in particular, the shotcrete/rock interface. Furthermore, the hypothesis from the literature review is tested and the results of the laboratory tests are presented.When water freezes, a 9 % volumetric expansion occurs according to the phase transition into ice. This can exert a pressure on the adjacent material. If this ice pressure exceeds the tensile strength of the adjacent material or the adhesive strength of the shotcrete/rock interface, the material will be damaged. The degree of damage depends, among other factors, on the degree of saturation of the material. A partially saturated material can resist breakage despite its low tensile strength, because ice expansion and pore-water distribution can occur in pores which were initially filled with air. A fully saturated material however yields to frost action regardless of its tensile strength, because it has none of the free space this expansion requires.Volumetric expansion is not the only cause of frost shattering and research shows that the frost action in rocks is the same as in soils, when the rock has access to water during freezing. In soil, water is drawn towards the frozen fringe and causes ice lenses to grow. In a similar manner water tends to migrate in rock and causes ice bodies to grow inside pores and cracks. This water migration takes place because a thin film of adsorbed water occurs at the surface of mineral particles and it is in this water film that water is able to migrate towards the frozen zones. Experimental work has shown that a considerable amount of adsorbed water remains unfrozen at sub-zero temperatures not only in soils, but also in rocks, which enable water migration.Water migration and ice growth thus depend not only on access to water and freezing temperatures, but also on the duration of these temperatures and the freezing rate. If rock or shotcrete is subjected to rapid freezing, the thickness of the water film is quickly reduced and the water migration is inhibited, which limits frost damages to rock and shotcrete. By contrast, a slow freezing allows water migration to occur over a longer period, which can result in greater frost damage to rock and shotcrete. The field investigations found changes to the freezing periods as well as their duration to be of major importance to ice formation growth. If the freezing period was of long duration, several of the cracks and the leakage spots freeze. If leakage is subjected instead to short periods of freezing and thawing, the water in the crack will never freeze and will continue to leak, resulting in ice formation growth. In cold areas, such as the north of Sweden, this problem takes place even far inside the tunnels. This phenomenon occurs because the leakage water transports heat from the rock mass to the cold tunnel wall. The heat content of the water keeps the rock around the crack opening from freezing despite sub-zero tunnel air temperatures. Hence, the leakage spot will continue to leak, until a certain temperature and temperature duration is achieved, which results in ice formations when the water meets the cold tunnel air. Another experience in the field investigations was that the rock and shotcrete fall-outs often occurred in areas with leakage problems.The results of the laboratory tests performed in this licentiate project also show that water in combination with freezing temperature can cause degradation problems. The tensile tests undertaken, showed that the adhesive strength decreased about 50 % when the shotcrete/rock samples had been subjected to freeze-thaw cycles. Furthermore, acoustic emission measurements (AE) showed that more events took place when the shotcrete/rock panels had access to free water during freezing. The literature review, field investigations of railway tunnels and the laboratory tests shows that access to water during freezing can cause damage to the shotcrete/rock interface. This confirms the hypothesis that shotcrete and rock fall-outs can occur because ice pressure in a crack or at the interface exceeds the tensile strength of the material or the adhesive strength between rock and shotcrete. One thing that the laboratory tests failed to provide a satisfactory answer to, was whether these fall-outs could occur due to widening of an initially small area of poor adhesion around a rock crack opening. However, the laboratory test showed a lot of activity during freezing in those areas prepared with poor adhesion. It thus it appears that small areas of poor adhesion in some way affect deterioration of the adhesive strength of the shotcrete/rock interface.

  • 169.
    Andrén, Anna
    Luleå tekniska universitet.
    Degradation of rock and shotcrete due to ice pressure and frost shattering2006Report (Other academic)
    Abstract [en]

    In the past few years Banverket has observed an increase in the number of incidences involving fall outs of shotcrete and rock in railway tunnels. Several research projects were therefore initiated by Banverket. This project “Degradation of rock and shotcrete due to ice pressure and frost shattering” is one of them. The purpose of this report is to gather experience and information about how ice is formed and how ice pressure influences fault zones, cracks and the interface between rock and shotcrete. When water freezes, a 9% volumetric expansion occurs according to the phase transition into ice. This can exert a pressure on the adjacent material. If there is water in small openings such as pores or cracks that cannot allow for a 9% volume expansion, breakage of the adjacent material will occur. The volumetric expansion of water/ice can only be prevented by pressures of 207 MPa, which is the pressure melting point of ice. As a comparison, consider a rock with a tensile strength in the order of 10 MPa. This rock material cannot prevent the ice from forming. Therefore, in a saturated rock there will always be a breakage if the water is freezing in a confined space. If the pressure of ice exceeds the tensile strength of the adjacent material, the material will be damaged, and the degree of damage is besides other factors dependent on the degree of saturation of the rock. A partially saturated rock can resist breakage despite its low strength because the expansion of ice and distribution of pore water can occur in pores that were initially filled with air. A fully saturated rock however yields to frost action regardless of its strength, because it doesn’t have any free space, which is needed for the expansion. But the 9% volumetric expansion is not the only cause of frost shattering. Research shows that the frost action in rocks is the same as in soils when the rock has access to water during freezing. In soil, water is drawn towards the frozen fringe and causes ice lenses to grow. In a similar manner water tends to migrate in rock and causes growth of ice bodies inside pores or cracks. The water migration takes place due to the fact that a thin water film of adsorbed water occurs at the surface of mineral particles and it is in this water film that the water has the opportunity to migrate towards the frozen zones. Experimental work has shown that considerable amount of adsorbed water remains unfrozen at subfreezing temperatures not only in soils, but also in rocks. This encourages the migration. With continuous decrease of temperature, the adsorbed water in the water film starts to freeze and the part of unfrozen water is reduced. Thus with decreasing temperature the water film, which separates the ice from the solid particles become thinner. This reduces the permeability of the material and inhibits the water migration towards the frozen fringe. With further decreasing of the temperature the migration can stop and so also the growth of ice bodies. The water migration and thereby the ice growth is not only dependent upon access to water and freezing temperatures, but also on the freezing rate and duration. If the rock is exposed to a rapid freezing rate, the thickness of the water film is quickly reduced and the water migration becomes inhibited, which delimits the frost damages of rock and shotcrete. In contrast, slow freezing rate permits water migration to occur for a longer period, which can result in greater frost damage of rock and shotcrete.

  • 170.
    Andrén, Anna
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Dahlström, Lars-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Temperaturflöden i järnvägstunnlar – Glödberget2011Report (Other academic)
    Abstract [en]

    During the winter ice is causing major problems in several of the Swedish Transport administrations railway tunnels. Freezing water is forming icicles and pillars that can fall down at track, and grow so large that they intrude on the clearance gauge. Lighting equipment and cables can be broken because of the ice load and tracks can become cowered with ice Periodic freezing can cause frost shattering and this process can cause fall-outs of rock and shotcrete. In order to maintain safety and prevent traffic disruption, many tunnels requiring extensive maintenance. In order to reduce maintenance of the tunnels, improved knowledge about frost penetration and the effects of ice pressure on the load-bearing capacity of the tunnel is required. 2002 the University of Gävle and KTH performed a model study to determine the temperature conditions in tunnels. To verify the model study field measurements are carried out in collaboration between the Transport Administration and Luleå University of Technology. This technical report describes the tests conducted so far in the Glödberget tunnel at Nyåker, 80 km south-west of Umeå. Measurements show that the developed models underestimate the frost penetration. Although the tunnel is 1680 meters long, the frost penetrates the entire length of the tunnel even if the temperature outside the tunnel is just a few degrees below zero. A contributing factor to why the field measurements and model do not conform can be that the model study is based on a completely uninsulated tunnel. In the Glödberget tunnel a large part of the walls and roof are covered the frost insulated drains. The function of the frost insulated drains is to prevent the cold tunnel air from reaching a leakage point and causing water to turn into ice. However, the insulation does not only prevent the cold air from reaching the rock, but also prevents the heat from the rock mass from entering the tunnel and warming up the cold tunnel air. Consequently, the frost penetrates further into the tunnel than it would do if the heat from the rock mass were allowed to warm up the outside air on its way into the tunnel. The amount of frost insulated drains and how much of the tunnel walls and roof that are covered are thereby affecting the length of the frost penetration. Temperature measurements has been carried out down into the ballast bed. To eliminate the risks with freezing drainage water, the drainage pipes are located at a depth of 2 m under the level of the rails. Measurements show that the temperature does not penetrate as far down as earlier feared and the depth of the pipes in the middle parts of the tunnel could be made shallower, with respect to risk of frost. Temperature measurements behind a frost insulated drain in the middle of the track tunnel, has shown that drains are able to smooth out the temperature changes that occur in the tunnel air. But when the temperature is negative for a longer period, the temperature behind the drain drops below 0ºC. Then the drainage ability is reduced due to icing and it can cause frost damage to the drain. Measurements of air temperature in the adjacent service tunnel shows how frost penetration is affected by air movement. The service tunnel is closed with gates at both ends. When the air in a tunnel is not exposed to movement, it is heated by geothermal heat and adopt the same temperature as the rock. Rock temperatures usually coincide with the average annual temperature applicable to the area where the tunnel is located. For the Glödberget tunnel there is a very good agreement between the average annual temperature for the area and the measurements performed in the service tunnel.

  • 171.
    Andrén, Anna
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Dahlström, Lars-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Temperaturflöden i järnvägstunnlar och konsekvenser för drift och underhåll2008In: Bergmekanikdag: föredrag vid Bergmekanikdag i Stockholm 10 mars 2008, Stiftelsen bergteknisk forskning - Befo , 2008Conference paper (Other academic)
  • 172.
    Ansin, Frida
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Rödin, Matilda
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Exploateringsavtal: Samverkan mellan kommun, lantmäterimyndighet och exploatör2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On January 1st 2015 an amendment passed in the Planning and Building Act in order to simplify and rationalize the detailed development plan process. The amendment includes a new part for cadastral authority in the plan process and new rules for development agreement. The municipalities should adopt guidelines for these agreements. The aim of this study was to describe how the collaboration between municipality, cadastral authority and developer works when it comes to development agreement and how the amendment in the Planning and Building Act concerning the development agreement has affected these participants.

    To answer the thesis a web survey was sent to all municipalities in Sweden to get an overview of how the amendment has influenced the country. Semi-structured telephone interviews were also performed in five municipalities that have adopted guidelines for the development agreements. The interviews were performed with land development engineers, cadastral supervisors and developers to receive their perspective of the collaboration and how the amendment has affected them.

    The results of the study have shown that negotiations have started earlier between municipalities and developers after the amendment in the Planning and Building Act passed. The municipalities also need to pay compensation when they take land for public places after the amendment. The cadastral authority’s more active part has contributed to assure that ambiguities and shortcomings might be solved in the development agreement. However, it is still too early to tell what the cadastral authorities part has contributed in the development agreements. The developer has got a major opportunity to influence the development agreements. The collaboration between municipalities, cadastral authorities and developers has become clearer and improved but overall it is unchanged. There are opportunities for improvement in the long term.

  • 173.
    Antevik, Fredrik
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Utvärdering av efterinjektering med polyuretan utifrån geologiska och hydrogeologiska grundförutsättningar2016Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    The aim of this master thesis is to evaluate the results of selective post-excavation grouting with polyurethane resin in the subway of Stockholm.Dripping and leakage of water into hard rock tunnels is a costly and commonly occurring problem. Water leakage does not only lead to damage to tunnel installation but may also affect the area above the tunnel due to lowering of the ground water table. To solve this problem there are several methods to prevent water entering the tunnel or to divert it. One of the preventing methods are to grout using polyurethane based resins.This thesis evaluates a drip sealing project where eight point leakages where grouted during November 2015. Drip mapping was carried out before and after the grouting to evaluate the change in leakage amount to determine whether the grouting methodology is suitable for future projects. The drip mapping was carried out during a year before the sealing attempt to investigate the leakages natural variation and with greater certainty being able to evaluate the leakage change after the grouting had been carried out.The evaluation of the grouting showed that none of the point leakages were sealed to 100 %. Only three of the leakages decreased, four increased and one showed no change. The natural variations during the evaluation period, during and after the grouting attempt indicates a natural rise in leakage amount induced by an increase in precipitation and rising seasonal trend.The change in leakage amount for every leakage point was compared to geological and hydrogeological parameters to be able to explain the cause of the results and to determine which conditions the methodology depends on. The correlation with original leakage amount, grouting volume and hydraulic aperture where the strongest and could best be explained by second degree polynomials. By using the equations for the polynomials an interval could be determined where the grouting methodology theoretically would lead to the greatest decrease in leakage amount. There are some uncertainty in the interpretation whether a natural signal in the grouting results led to a correlation due to an internal coupling between the parameters.

  • 174. Appelgren, J
    et al.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Nord, G
    Automation and smart drill rigs2006In: Mine planning and equipment selection 2006: Fifteenth International Symposium on Mine Planning & Equipment Selection / [ed] Marilena Cardu ; Enrica Michelotti, Fiordo , 2006Conference paper (Refereed)
  • 175.
    Arasteh Khouy, Iman
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Cost-effective maintenance of railway track geometry: a shift from safety limits to maintenance limits2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Railway infrastructure is a complex system which comprises different subsystems. Long life span is one of the important aspects of this prime mode of transport. However, the useful life of its assets is highly dependent on the maintenance and renewal strategy used during the assets’ life cycle. Today’s demands on the railway industry call for increased capacity, including more trains, travelling at higher speeds with higher axle loads. This increased usage results in higher degradation of railway assets and higher maintenance costs. Formerly, railway maintenance procedures were usually planned based on the knowledge and experience of the infrastructure owner. The main goal was to provide a high level of safety, and there was little concern for economic issues. Today, however, the deregulated competitive environment and budget limitations are forcing railway infrastructures to move from safety limits to cost-effective maintenance limits to optimise operation and maintenance procedures. The goal is to make operation and maintenance cost-effective while still meeting high safety standards.One of the main parameters to assure railway safety and comfortable railway service is to maintain high quality of track geometry. Poor quality of track geometry, directly or indirectly, may result in safety problems, speed reduction, traffic disruption, greater maintenance cost and higher degradation rate of the other railway components (e.g. rails, wheels, switches and crossings etc.). The aim of this study is to develop a methodology to optimise track geometry maintenance by specifying cost-effective maintenance limits. The methodology is based on reliability and cost analysis and supports the maintenance decision-making process. The thesis presents a state-of-the-art review of track geometry degradation and maintenance optimisation models. It also includes a case study carried out on the iron ore line in the north of Sweden to analyse the track geometry degradation and discuss possible reasons for the distribution of failures along the track over a year. It describes Trafikverket’s (Swedish Transport Administration) maintenance strategy regarding measuring, reporting on and improving track quality, and it evaluates the efficiency of this strategy. It introduces two new approaches to analyse the geometrical degradation of turnouts due to dynamic forces generated from train traffic. In the first approach, the recorded measurements are adjusted at crossing point and then the relative geometrical degradation of turnouts is evaluated by using two defined parameters, the absolute residual area (ARa) and the maximum settlement (Smax). In the second approach, various geometry parameters are defined to estimate the degradation in each measurement separately. It also discusses optimisation of the track geometry inspection interval with a view to minimising the total ballast maintenance costs per unit traffic load. The proposed model considers inspection time and the maintenance-planning horizon time after inspection and takes into account the costs associated with inspection, tamping and risk of accidents due to poor track quality. Finally, it proposes a cost model to identify the cost-effective maintenance limit for track geometry maintenance. The model considers the actual longitudinal level degradation rates of different track sections as a function of million gross tonnes (MGT) / time and the observed maintenance efficiency.

  • 176.
    Arasteh khouy, Iman
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Optimization of track geometry maintenance: a study of track geometry degradation to specify optimal inspection intervals2011Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Railway infrastructure is a complex system which comprises different subsystems. Long useful life span is one of the important aspects of this prime mode of transport. The useful life length of its assets is highly dependent on the maintenance and renewal strategy used during its life cycle. Today’s demands on the railway industry call for increased capacity, including more trains, travelling at higher speeds with higher axle loads. This increased usage will result in higher degradation of railway asset and higher maintenance costs. However, due to the competitive environment and limited budgets, railway infrastructure managers are compelled to optimize operation and maintenance procedures to decrease operation and maintenance costs while meeting high safety standards. To assure track safety and maintain high quality, a cost effective track maintenance strategy is required, one based not only on technical and/or safety limits but also on cost-effective maintenance thresholds. RAMS (Reliability, Availability, Maintainability and Safety) and LCC (Life Cycle Cost) analyses, which are derived from reliable track condition data, provide an approach to specify cost effective maintenance strategy to lessen corrective maintenance actions and downtimes.One of the main parameters to assure railway safety and comfortable railway service is to maintain high quality of track geometry. Poor track geometry quality, directly or indirectly, may result in safety problems, speed reduction, traffic disruption, greater maintenance cost and higher degradation rate of the other railway components (e.g. rails, wheels, switch, crossings etc.). The aim of this study is to develop a methodology to optimize track geometry maintenance by using historical geometry data. The methodology is based on reliability and cost analysis and supports the maintenance decision-making process to identify cost-effective inspection interval. An important phase of track geometry maintenance optimization is to estimate the track degradation rate. Obtaining knowledge about degradation helps to properly schedule maintenance activities such as inspection and tamping.The thesis provides a methodology to identify a cost-effective inspection interval based on track degradation rate and cost drivers. It contains state-of-the-art track geometry maintenance optimization. It describes Trafikverket’s (Swedish Transport Administration) maintenance strategy regarding measurements, reporting on and improving track quality, and it evaluates the efficiency of this strategy. Finally, it includes a case study carried out on the iron ore line in north of Sweden that runs from Boden to Gällivare to evaluate track geometry degradation and analyze the probability distributions of failures. A cost model is developed in order to find optimal inspection interval.Keywords: Track geometry degradation, Track maintenance optimization, Maintenance planning, Tamping

  • 177.
    Arasteh khouy, Iman
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Larsson-Kråik, Per-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Nissen, Arne
    Trafikverket.
    Juntti, Ulla
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Optimisation of track geometry inspection interval2014In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 228, no 5, p. 546-556Article in journal (Refereed)
    Abstract [en]

    The measurement and improvement of track quality are key issues in determining the time at which railway maintenance must be performed and its cost. Efficient track maintenance ensures optimum allocation of limited maintenance resources which has an enormous effect on maintenance efficiency. Applying an appropriate tamping strategy helps reduce maintenance costs, making operations more cost-effective and leading to increased safety and passenger comfort levels. This paper discusses optimisation of the track geometry inspection interval with a view to minimising the total ballast maintenance costs per unit traffic load. The proposed model considers inspection time, the maintenance-planning horizon time after inspection and takes into account the costs associated with inspection, tamping and risk of accidents due to poor track quality. It draws on track geometry data from the iron ore line (Malmbanan) in northern Sweden, used by both passenger and freight trains, to find the probability distribution of geometry faults.

  • 178.
    Arasteh khouy, Iman
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Larsson-Kråik, Per-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Nissen, Arne
    Trafikverket.
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Cost-effective track geometry maintenance limits2016In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 230, no 2, p. 611-622Article in journal (Refereed)
    Abstract [en]

    In the past, railway maintenance actions were usually planned based on the knowledge and experience of the infrastructure owner. The main goal was to provide a high level of safety, and there was little concern about economic and operational optimisation issues. Today, however, a deregulated competitive environment and budget limitations are forcing railway infrastructures to move from safety limits to cost-effective maintenance limits to optimise operation and maintenance procedures. By so doing, one widens the discussion to include both operational safety and cost-effectiveness for the whole railway transport system. In this study, a cost model is proposed to specify the cost-effective maintenance limits for track geometry maintenance. The proposed model considers the degradation rates of different track sections and takes into account the costs associated with inspection, tamping, delay time penalties, and risk of accidents due to poor track quality. It draws on track geometry data from the Iron Ore Line (Malmbanan) in northern Sweden, used by both passenger and freight trains, to estimate the geometrical degradation rate of each section. The methodology is based on reliability and cost analysis and facilitates the maintenance decision-making process to identify cost-effective maintenance thresholds.

  • 179.
    Arasteh khouy, Iman
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Larsson-Kråik, Per-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Nissen, Arne
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Geometrical degradation of switches and crossings on a Swedish heavy haul railroad: a case study2013In: Proceedings of 10th International Heavy Haul Association Conference, New Delhi, India, 2013, Vol. 1, p. 26-32Conference paper (Refereed)
    Abstract [en]

    Switches and crossings (S&Cs) are one of the most critical components of railway track systems in terms of safety, operation and maintenance. Each year, a considerable part of the maintenance budget is spent on inspection, maintenance and renewal of S&Cs. However, applying a cost-effective maintenance strategy helps to achieve the best performance at the lowest possible cost. In Sweden, the geometry of S&Cs is inspected at pre-defined time intervals by the STRIX track measurement car. In this paper, time series for the measured longitudinal level of S&Cs on the Iron Ore Line (Malmbanan) in northern Sweden have been used. Two parameters have been defined in this study, namely the absolute residual area (ARa) and the maximum settlement (Smax), to analyse the geometrical degradation of switches and crossings due to dynamic forces generated from train traffic. The paper also evaluates the growth rate of the longitudinal level degradation as a function of million gross tonnes (MGT). The results facilitate correct decision making in the maintenance process through understanding the degradation rate and defining the optimal maintenance thresholds for the planning process. In the long run this will lead to a cost-effective maintenance strategy with optimized inspection and maintenance intervals.

  • 180.
    Arasteh khouy, Iman
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Larsson-Kråik, Per-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Nissen, Arne
    Trafikverket.
    Lundberg, Jan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Kumar, Uday
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Geometrical degradation of railway turnouts: a case study from a Swedish heavy haul railroad2014In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 228, no 6, p. 611-619Article in journal (Refereed)
    Abstract [en]

    Turnouts are critical components of track systems in terms of safety, operation and maintenance. Each year, a considerable part of the maintenance budget is spent on their inspection, maintenance and renewal. Applying a cost-effective maintenance strategy helps to achieve the best performance at the lowest possible cost. In Sweden, the geometry of turnouts is inspected at predefined time intervals using the STRIX / IMV 100 track measurement car. This study uses time series for the measured longitudinal level of turnouts on the Iron Ore Line (Malmbanan) in northern Sweden. Two different approaches are applied to analyse the geometrical degradation of turnouts due to dynamic forces generated by train traffic. In the first approach, the recorded measurements are adjusted at the crossing point and then the relative geometrical degradation of turnouts is evaluated by using two defined parameters, the absolute residual area and the maximum settlement, In the second approach, various geometry parameters are defined to estimate the degradation in each measurement separately. The growth rate of the longitudinal level degradation as a function of million gross tonnes / time is evaluated. The proposed methods are based on characterisation of the individual track measurements. The results facilitate correct decision-making in the maintenance process through understanding the degradation rate and defining the optimal maintenance thresholds for the planning process. In the long run, this can lead to a cost-effective maintenance strategy with optimised inspection and maintenance intervals.

  • 181.
    Arasteh khouy, Iman
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Juntti, Ulla
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Nissen, Arne
    Larsson-Kråik, Per-Olof
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Evaluation of track geometry maintenance for heavy haul railroad in Sweden: a case study2014In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 228, no 5, p. 496-503Article in journal (Refereed)
    Abstract [en]

    The measurement and improvement of track quality are key issues in determining both the restoration time and cost of railway maintenance. Applying the optimal tamping strategy helps reduce maintenance costs, making operations more cost effective and leading to increased safety and passenger comfort. In this paper, track geometry data from the iron ore line (Malmbanan) in northern Sweden, which handles both passenger and freight trains, are used to evaluate track geometry maintenance in cold climate. The paper describes Trafikverket’s (Swedish Transport Administration) tamping strategy and evaluates its effectiveness in measuring, reporting, and improving track quality. Finally, it evaluates the performance of the maintenance contractor and discusses the importance of the functional requirements stated in the outsourcing contracts.

  • 182.
    Arasteh khouy, Iman
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Schunnesson, Håkan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Nissen, Arne
    Trafikverket.
    Juntti, Ulla
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Evaluation of track geometry degradation in Swedish heavy haul railroad: a case study2012In: International Journal of COMADEM, ISSN 1363-7681, Vol. 15, no 2, p. 11-16Article in journal (Refereed)
    Abstract [en]

    The measurement and improvement of track quality are key issues in determining both the time and cost of railway maintenance. Efficient track geometry maintenance ensures optimum allocation of limited maintenance resources and has an enormous effect on maintenance efficiency. Applying the appropriate tamping strategy also helps reduce maintenance costs, making operations more cost effective and leading to increased safety and passenger comfort. In this paper, track geometry data from the iron ore line in northern Sweden, which handles both passenger and freight trains, are used to calculate track quality degradation trend in a cold climate. The paper describes Trafikverket’s (Swedish Transport Administration) tamping strategy and illustrates the distribution of safety failures in different seasons. It also analyses the track geometry degradation and discuss about the possible reasons for distribution of failures over a year and along the track.

  • 183.
    Arbeus, Rickard
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Economics and Management (Div.).
    Fransson, Dan
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.), Industrial Economics and Management (Div.).
    A Post Announcement Trading Strategy2011Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Previous research has shown that trading strategies based on the Post Earnings Announcement Drift (PEAD), the phenomenon where stock prices tend to drift up (down) for firms that report unexpectedly high (low) earnings, and fundamental analysis, in which financial data is used to evaluate a company's value, can generate risk-adjusted excess returns. The purpose of this report is to investigate whether a combined trading strategy, based on both PEAD and fundamental analysis, can generate higher returns than each trading strategy individually. Standardized Unexpected Earnings (SUE) (Setterberg (2007), Bernard and Thomas (1990), and others) is used to take advantage of the PEAD and the Piotroski (2000) model for fundamental analysis. Observations are made on the Stockholm Stock Exchange from 2002Q3 to 2009Q4. The results show that a combined hedge strategy based on a long position in the highest (SUE) decile with financially strong companies and a short position in the lowest (SUE) decile of financially weak companies on average generate a significant risk-adjusted excess return of 5.6% per quarter (24.2% per year) with 80-day holding period. The dual approach has thus generated an average of 2.6 and 1.6 percentage points higher return per quarter (10.8% and 6.6% per year) than a trading strategy solely based on PEAD or fundamental analysis.

  • 184.
    Argerich, Jennie
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Mathematics.
    Offentliga rum: En statistisk undersökning av upplevelsen av platserna Hornstull torg och Skärhomstorget2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis evaluates public spaces based on the relationship between humans and thephysical environment. A comparative study was developed, comparing two differentpublic spaces, Hornstull torg and Skärholmstorget. The two places have beenstatistical analysed through chisquare tests and evaluated based on different factors, toidentify strengths and weaknesses. The factors have been identifiedas important forpublic spaces to be perceived as attractive and have been determined with help froma theoretical framework based on urban research.

    Social progress has resulted in changes on how we use public spaces which createsnew demands on the surroundings. The study concludes that a public space'sattractiveness is a complicated and multifolded concept that has different meanings fordifferent people. On the other hand, it is clear that public spaces are connected toboth social and physical structures and the combination of these two dimensionsdecides how the place is perceived and used.

    The results from the chisquare-tests show differences depending on gender and ageon how they experience public space. Skärholmstorget fulfils more of the factors thathave been identified as crucial for an attractive public space than Hornstull torg does.However, the majority of the respondents perceive Skärholmstorget as moreinsecure than Hornstull torg. This may have effect on how often the public space isused.

  • 185.
    Aronsson, Anders
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013).
    Bidrar GLONASS till bättre positionering?2013Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [sv]

    Från den 1 april 2006 gavs möjligheten att använda GLONASS-systemet vid NRTK-mätningar som dessförinnan enbart använde sig av GPS-systemet. Allt fler inbyggda positioneringstjänster i vår nya teknik går nu mot att börja använda sig av både GPS och GLONASS-systemen. Tillgången till både amerikanska och ryska satelliter borde göra att vi får bättre, mer exakta och stabila mätningar vid dåliga förhållanden. Men är verkligen följden av att använda fler satelliter lösningen, eller räcker det i vissa tillfällen med enbart GPS-satelliter. Är den mer utbreda användningen av GLONASS-satelliter bara marknadsföring från företagen för att få sälja mer, dyrare och nyare produkter och därmed lura konsumenten att den är i behov av uppgraderade produkter som har GLONASS-stöd.

    Syftet var att undersöka om GPS och GLONASS förbättrar mätningarna och tillgängligheten i öppna respektive störda miljöer eller är det bara onödigt för konsumenten att sträva efter att positioneringsverktyget i ny teknik ska stödja båda satellitsystemen.

    En annan fråga är om det finns viss ny teknik som är tillämpade för olika områden där behovet är antingen större av GPS och GLONASS eller de områden där enbart GPS räcker till och ger minst lika goda mätningar och positionering.

    I detta examensarbete gjordes NRTK mätningar mot SWEPOS på ett antal kända punkter vid Karlstads Universitet där punkterna hade olika förutsättningar så som öppna och störda miljöer. Mätningarna gjordes med enbart GPS- respektive med GPS och GLONASS-satelliter påslagna. De bestämda koordinaterna i plan för de kända punkterna jämfördes med koordinaterna från mätningarna med enbart GPS respektive med GPS och GLONASS.

    De extra GLONASS-satelliterna är bra att använda sig av när man ska mäta i störda miljöer, de hjälper till att få en bättre noggrannhet. När man dock är i icke störda miljöer med fri sikt mot satelliterna räcker enbart GPS-satelliterna långt. Med den nya tekniken som kommer så finns ofta GLONASS-systemet inbyggt och är i de flesta fall är ingen ytterligare kostnad som konsumenten behöver ta utan är endast ett bra komplement oavsett användningsområde.

  • 186. Arvanitidis, Ioannis
    et al.
    Nyberg, Ulf
    Ouchterlony, Finn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Diameterns inverkan på detonationsegenskaperna hos emulsionssprängämne E682 i cylinderprovet2004Report (Other academic)
    Abstract [en]

    Cylinder expansions tests with 4 different diameters ranging from 40 to 100 mm have been conducted on the generic emulsion explosive E682, both pure and with 20 % ANFO content. The work capacity is expressed in terms of the Gurney energy EG, which equals the sum of the kinetic energy of the copper tube and the radial kinetic energy of the gases. The purpose was to study the effect of charge diameter on the explosive's work capacity expressed as the Gurney energy and to supplement earlier work done by Nie (2001). The radial expansion has been measured as well as the velocity of detonation in 11 copper tubes. The effect of ANFO granules were tested by making a mixture of E682 with 20% ANFO. The ANFO used in the present study is Anolit from Dyno Nobel, which basically is the same product as the Prillit A used by Nie. The average density of pure E682 was 1130 kg/m3 and that of E682 with 20% ANFO 1200 kg/m3. The results from the new batch of E682 show similarities with the old batch regarding VOD as function of inverse charge diameter but the trend of the Gurney energy is different from the first experiments carried out by Nie. This could be due to previous tolerance variations in the tube dimensions. The Gurney energy seems to be independent of the charge diameter between 40-100 mm in the new experiments. The measured Gurney energy for pure E682 was 1.77 ± 0.06 MJ/kg and that of E682 with 20% ANFO 1.71 ± 0.07 MJ/kg which is somewhat lower. The use of 20% ANFO in E682 results in the same volume based Gurney energy as for pure E682 however. The overall average is 2.02 ± 0.02 MJ/dm3. The energy utilisation ratio is 0.58 ± 0.03 for pure E682 and 0.53 ± 0.03 for E682 with 20% ANFO. This is slightly lower than for the Titan 6000 series gassed bulk emulsion but higher than for pure ANFO. The detonation pressure decreases with the charge diameter however and this indicates that a smaller hole diameter in rock blasting leads to a lower detonation pressure without loosing work energy when keeping the powder factor constant.

  • 187.
    Arvids, Mattias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Samfälligheter: Föreningsförvaltning och Samfällighetsföreningsregistrets aktualitetsgrad2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Samfälligheter har en mycket viktig roll i Sverige för samverkan mellanfastigheter i förvaltningen av gemensamma resurser. Dessa kan förvaltas på två vis; genom föreningsförvaltning och delägarförvaltning. Föreningsförvaltninglämpar sig bäst för större samfälligheter som kräver många förvaltningsåtgärder och har många medlemmar. En sådan förening sköts genom en styrelse som är vald av medlemmarna. Styrelsens uppdrag går ut på att enligt lagstiftningen följa föreningens stadgar och stämmobeslut samt att se till att befintliga anläggningar förvaltas enligt anläggningsbeslutet och att nya anläggningar blir utförda. Detta uppdrag innebär dock vissa svårigheter; engagemanget sker på ideell grund och lagen innehåller inga närmare krav på styrelsens kompetens, vilket öppnar upp för olika former av problematik. Uppgifter om samfällighetsföreningarna står att finna i Samfällighetsföreningsregistret och Fastighetsregistret. Det förstnämnda har en bristande kvalité på sina uppgifter vilket utgör ett problem för såväl föreningarna som för utomstående.

    Med dessa förhållanden som bakgrund görs en studie på rådande lag och regelverk i området kombinerat med kvalitativa intervjuer av ordföranden vid samfällighetsföreningar. Syftet är att undersöka hur styrelsens uppdrag ser ut vid föreningsförvaltning, hur denna förvaltning fungerar i praktiken och vilka eventuella problem som står i vägen för optimalt fungerande samfällighetsföreningar, samt vilka åtgärder som kan tänkas ge Samfällighetsföreningsregistreten förbättrad registerkvalité.

    Resultatet av studien visar att det största problem området utgörs av medlemmarnas i många fall bristande engagemang samt styrelsernas avsaknad på specialkompetens. Det framkommer att de bäst lämpade åtgärderna för att avhjälpa bristen på kompetens utgörs av att upprätta dokument med lättöverskådlig information till styrelserna, men även till medlemmarna som på så vis skulle kunna ställa högre krav på styrelsens arbete och själva upptäcka fel och brister i förvaltningen. Även en del förtydligande av bestämmelserna i lagen anses vara lämpligt. För att öka medlemmarnas engagemang uppkommer inga konkreta förslag från det resonemanget som förs.

    Genom att erbjuda samfällighetsföreningarna möjligheten att registrera ändrade uppgifter på Internet samt ge dem en belöning för detta i slag av en medlemsförteckning bör styrelserna bli mer noggranna i detta avseende, vilket framkommer i studien. Den främsta orsaken till att samfällighetsföreningarna inte anmäler ändringar i tillfredsställande grad beror på bristande kunskap, vilket bör kunna avhjälpas genom att någon form av broschyr ges ut till styrelsemedlemmarna innehållande relevant information.

  • 188.
    Asaad Sharif Elemara, Hadil
    Örebro University, School of Science and Technology.
    GRUNDLÄGGNINGSMETODER-VAL AV GRUNDLÄGGNINGSMETOD FÖR SMÅHUS I ÖREBRO LÄN2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Foundations support entire houses and are required to be adequately well-built to carry a building’s

    mass for many years without facing problems due to environmental impacts such as moisture and

    frost. This work covers three basic types of foundations; concrete slab, crawl space and block

    foundation. The aim of this work is to investigate the construction methods of the foundations

    mentioned above, which are used within the construction of single-family homes in the city of

    Örebro, Sweden. Additionally, the basis of selection of these foundations by various construction

    companies in respect to risk of moisture-related problems is examined.

    Information about the foundations is collected from scholarly literature as well as qualitative

    interviews with seven construction companies’ experts. Ultimately, this study found that concrete

    slab with underlying insulation is more commonly used within the construction of single-family

    homes in Örebro than the other alternatives. Operators find that this foundation has many

    advantages in comparison with the other foundation techniques.

  • 189.
    Asanovic, Darko
    et al.
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Kha, Mattias
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Förbättring av tillgänglighet i tillgänglighetsanpassade naturreservat2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    More than half a million people in Sweden are affected by some sort of disability. During recreational activities in nature areas, these people might encounter difficulties such as inadequate accessibility. The Swedish society requires that all citizens should have the same possibilities. The purpose of this thesis is to improve the accessibility for people with disabilities. The aim is to examine occurring flaws in accessible nature reserves and suggest possible improvements.The questions that will be answered are as follows:• What flaws do accessible nature reserves have, and how do they affect the visitors?• What improvements can be made in nature reserves to increase accessibility?To answer the questions, a case study was done, where five different nature areas were visited. During the case study, various flaws in the accessibility were observed and analysed. Prior to the case study, requirements and scientific research regarding accessibility was studied. Using this, suggestions for improving the accessibility were made. . Most of the improvements that could be made in the studied nature reserves were presumed to be applicable in other nature reserves in Sweden.With the case study in mind, the accessibility was considered in need of various improvements. The accessibility was studied from three out of four of the Swedish disability association’s categories; physical, communicative, and informative accessibility. The flaws that were encountered in the studied areas were due to incorrect design, or insufficient maintenance. Most of the flaws could be corrected in simple ways, but the flaws that were due to incorrect design or planning would require more work. After the case study it was discovered that supposedly “accessible” trails, according to different websites, had varying levels of accessibility. An accessible recreational area will benefit all types of visitors, not only people with disabilities. It will be more convenient and enables visits with strollers. An area cannot be made accessible for all types of visitors, but can be made accessible for as many visitors as possible.

  • 190.
    Ascione, Luigi
    et al.
    UNISA, Italy.
    Caron, Jean-François
    ENPC, France.
    Godonou, Patrice
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    van Ijselmuijden, Kees
    RHDHV, the Netherlands.
    Knippers, Jan
    ITKE, Germany.
    Mottram, Toby
    Warwick AC, UK.
    Oppe, Matthias
    KHING, Germany.
    Gantriis Sorensen, Morten
    Fiberline, Denmark.
    Taby, Jon
    FIRECO, Norway.
    Tromp, Liesbeth
    RHDHV, the Netherlands.
    Prospect for new guidance in the design of FRP: Support to the implementation, harmonization and further development of the Eurocodes2016Report (Refereed)
    Abstract [en]

    Over the last twenty years, many innovative solutions have confirmed the usefulness of composite structures realized with FRPs (Fibre Reinforced Polymer or Plastic). The need of European standards for use of fibre reinforced polymer composites in civil engineering was justified in 2007 in the JRC Report EUR 22864 EN. The new European technical rules will be developed using the existing organization of CEN/TC250.The present report has been worked out in the frame of CEN/TC250/WG4 activities. The report encompasses:

    • Part I, which introduces the policy framework and the CEN/TC250 initiative
    • Part II, which gives a prospect for CEN guidance for the design and verification of composite structuresrealized with FRPs

    The report presents scientific and technical background intended to stimulate debate and serves as a basis for further work to achieve a harmonized European view on the design and verification of such structures. This has been the main impulse to include the work item of the Fibre Reinforced Polymer Structures in the Mandate M/515 with high priority.

  • 191.
    Ask, D.
    et al.
    Vattenfall Power Consultant AB, Luleå.
    Stephansson, O.
    GeoForschungsZentrum Potsdam.
    Cornet, F.H.
    Institut de Physique du Globe de Strasbourg.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Rock stress, rock stress measurements, and the Integrated Stress Determination Method (ISDM)2009In: Rock Mechanics and Rock Engineering, ISSN 0723-2632, E-ISSN 1434-453X, Vol. 42, no 4, p. 559-584Article in journal (Refereed)
    Abstract [en]

    The primary objectives of this work are to (1) improve the understanding of the prevailing stress distribution at the Äspö Hard Rock Laboratory (HRL) in SE Sweden by employing an integrated stress determination approach, and in order to accomplish this (2) extend the existing stress integration methodology denominated integrated stress determination method (ISDM; Cornet in Comprehensive Rock Engineering vol 3, Pergamon Press, Oxford, pp 413-432, 1993a). The new developments of the ISDM involve a 12-parameter representation of the regional stress field in the rock mass (i.e., the full stress tensor and its variation with depth) that is applicable to hydraulic stress data (sleeve fracturing, hydraulic fracturing, and hydraulic tests on pre-existing fractures), overcoring data (CSIR- and CSIRO-type of devices), and to combinations of hydraulic and overcoring stress data. For the latter case, the elastic parameters of the overcoring technique may be solved in situ by allowing the hydraulic stress data to constrain them. As a result, the problem then involves 14 model parameters. Results from the study show that the ISDM effectively improves the precision of the prevailing stress field determination and that it is especially powerful for identification of consistencies/inconsistencies in an existing data set. Indeed, this is the very basic premise and goal of stress integration; combine all available data to achieve as complete a characterization of the mechanical stress model as possible, and not to identify a solution that fits only loosely the maximum amount of stress data.

  • 192.
    Ask, Daniel
    Luleå tekniska universitet.
    Evaluation of measurement-related uncertainties in the analysis of overcoring rock stress data from Äspö HRL, Sweden: a case study2003In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 40, no 7-8, p. 1173-1187Article in journal (Refereed)
    Abstract [en]

    A re-evaluation of overcoring results from the Borre Probe and the CSIRO HI cell was carried out at the Äspö HRL. The re-analysis revealed a number of measurement-related uncertainties for the two cells, e.g. bonding, temperature effects and identification of elastic parameters. These uncertainties were corrected and the re-analyzed strains were then used to determine the in situ stress field using standard least-squares technique. The results indicate lower stress magnitudes compared to the original interpretations and the results are in good agreement with existing hydraulic fracturing data as well as with theoretical vertical stress. Overall, the re-analysis indicates that the stress field at Äspö HRL is well constrained and relatively consistent with depth.

  • 193.
    Ask, Daniel
    Luleå tekniska universitet.
    Measurement-related uncertainties in overcoring data at the Äspö HRL, Sweden: Part 2: Biaxial tests of CSIRO HI overcore samples2006In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 43, no 1, p. 127-138Article in journal (Refereed)
    Abstract [en]

    This paper is the second dealing with measurement-related uncertainties of overcoring data undertaken at the Äspö Hard Rock Laboratory and focuses on the biaxial test data from CSIRO HI overcore samples. The first paper dealt with measurement-related uncertainties in connection with the overcoring phase [1]. The uncertainties identified in connection to biaxial tests of CSIRO HI overcore samples include too large applied pressures and poor sampling frequency. At the Aspo HRL, the results yield that most overcore samples fractured during biaxial testing, meaning that a significant part, 56%, of available strain gauge combinations were removed from calculations of the elastic parameters. Remaining strain gauge combinations indicate average values of 62′5 GPa for Young's modulus and 0.25′0.01 for Poisson's ratio, which are considerably lower than previously published values [2-5], and are in good agreement with results from biaxial tests on Borre Probe overcore samples .[6-10]. The stress calculations were obtained from re-analyzed elastic parameters and strains, and show primarily a reduction in stress magnitudes. Overall, the stress field obtained with different stress measurement methods and its variation with depth is now quite well resolved. The overcoring data suggest that the principal stresses are inclined with a vertical component dipping about 65° from the horizontal over the investigated rock volume (140-420 m depth). This is interpreted as a result of influence from the sub-vertical NE-2 Fracture Zone that divides the stress data into two stress domains [11], although it may also be an artefact because the σ[2]- and σ[3]-magnitudes are of the same order of magnitude.

  • 194.
    Ask, Daniel
    Luleå tekniska universitet.
    New developments in the integrated stress determination method and their application to rock stress data at the Äspö HRL, Sweden2006In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 43, no 1, p. 107-126Article in journal (Refereed)
    Abstract [en]

    The Integrated Stress Determination Method (ISDM) is a powerful tool for estimating the regional stress tensor from in-situ measurements of local stress tensors using a wide variety of stress measuring techniques. This study presents new developments of the ISDM: The stress field may be described with up to 12 model parameters; and is applicable to data from CSIR- and CSIRO HI-type of overcoring devices, hydraulic fracturing, hydraulic tests of pre-existing fractures (HTPF), as well as to combined data sets. Furthermore, in combined data sets, the hydraulic fracturing and/or HTPF data may be used to constrain the average elastic parameters, Young's modulus and Poisson's ratio. The new ISDM developments were applied to the extensive and recently re-analysed rock stress data at the Äspö Hard Rock Laboratory. The results reveal a good fit of the re-analysed data. Overall, the re-analysis indicates that the stress field at Äspö HRL is relatively well constrained and consistent with depth. The NE-2 Fracture Zone influences the stresses, and dividing the regional stress field into a NW and a SE stress domain. When the hydraulic fracturing data were used to constrain the average elastic parameters, Young's modulus, E, and Poisson's ratio, ν, quite similar results were obtained (E=50.8 GPa and v=0.33) compared with results from biaxial tests of overcore samples (E=61.6 MPa and v=0.26).

  • 195.
    Ask, Daniel
    et al.
    Vattenfall Power Consultant AB, Luleå.
    Cornet, F.H.
    Institute de Physique du Globe de Strasbourgh.
    Fontbonne, F.
    GEO-energies, Clermont-Ferrand.
    Nilsson, Tommy
    Jönsson, L.
    Hydraulikmontage i Luleå AB.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    A quadruple packer tool for conducting hydraulic stress measurements in mines and other high stress settings2009In: International Journal of Rock Mechanics And Mining Sciences, ISSN 1365-1609, E-ISSN 1873-4545, Vol. 46, no 6, p. 1097-1102Article in journal (Refereed)
  • 196.
    Ask, Maria
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Data report: consolidation state and stress ratio of clay-rich sediments from Site U13202009In: Proceedings of the Integrated Ocean Drilling Program, ISSN 1930-1014, Vol. 308Article in journal (Refereed)
    Abstract [en]

    Overpressure and fluid flow processes in the deepwater Gulf of Mexico were investigated during Expedition 308 of the Integrated Ocean Drilling Program.This data report presents the results from a reconsolidation test that was carried out on a clay-rich sample from the base of Brazos-Trinity Basin IV, at 276.40 m below seafloor. The sample was subjected to a stress path of uniaxial strain (K0 reconsolidation), and the test was conducted in an advanced triaxial cell under drained conditions. Posttest investigation revealed that the sample was disturbed by drilling. The results should be interpreted with care.The sample was loaded to a total effective vertical stress, σv′, of 24 MPa, corresponding to effective horizontal stress, σh′, of >16 MPa and vertical strain, εv, of 16%. The results propose an effective vertical yield stress of 2.03 MPa, which suggests a maximum pore fluid pressure in excess of hydrostatic water pressure of 0.24 MPa. Furthermore, the ratio between effective horizontal and vertical stresses is rather constant, ~0.7, even at high stress magnitudes.

  • 197. Ask, Maria
    In situ stress at the Cote d'Ivoire-Ghana marginal ridge from FMS logging in Hole 959D1998In: Proceedings of the Ocean Drilling Program. Scientific results, College Station, TX, 1998, p. 209-223Chapter in book (Other academic)
    Abstract [en]

    The orientation of the in situ stress between 550 and 925 meters below seafloor in Hole 959D has been derived from the analysis of caliper and electrical images of Formation MicroScanner data. Because of a high hole deviation (5°-13°), drill pipe wear has enlarged the hole in a northerly direction. As a result, the four-arm caliper analyses cannot distinguish between mechanically and stress induced borehole elongations. The FMS data show that one of the principal stresses is parallel to the borehole axis and that mainly tensile wall fractures have formed in the borehole wall. The tensile wall fractures demonstrate a 168° ± 8°N weighted mean orientation of the maximum horizontal stress. The upper 750 mbsf of the borehole comprises the majority of the tensile wall fractures, whereas they only occur sporadically below this depth. The change in the downhole distribution of fractures coincides with the transition from weaker to more compacted, stronger sedimentary rock. Furthermore, the integration of seismic and physical properties data suggests that this depth corresponds to the boundary between passive margin evolution and continent/ocean transform faulting. The orientation of the maximum horizontal stress in Hole 959D is almost perpendicular to the east-west maximum horizontal stress orientation of the first-order stress province in western and north central Africa. Through comparisons with (1) the orientations of the maximum horizontal stress in Hole 959D, (2) the maximum horizontal stress of three focal mechanisms from earthquakes in Ghana, and (3) the strike of the continental margin, it is suggested that lateral strength contrasts across the Côte d’Ivoire-Ghana Transform Margin are the most probable source for the observed stress orientations. It is further suggested that sediment loading and lateral variation in crustal thickness and density may only have a minor influence on the stress field in this area.

  • 198. Ask, Maria
    In situ stress from borehole breakouts in Denmark1996Licentiate thesis, comprehensive summary (Other academic)
  • 199. Ask, Maria
    In-situ and laboratory stress investigations using borehole data from the North Atlantic Ocean1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This doctoral thesis presents results from investigations ofin-situ and laboratory stress from borehole logging andlaboratory deformation experiments on drill-cores. The datacome from hydrocarbon exploration and production wells in theDanish Sector of the North Sea, and from boreholes drilled bythe Ocean Drilling Program (ODP). The drill-core samples werecollected from two ODP boreholes in the equatorial and easternAtlantic Ocean. The objectives for this project are: (1) to collect datafrom the North Atlantic Ocean where few or no stressmeasurements exist, and to incorporate the data into the WorldStress Map (WSM); (2) to determine the source of stress thatgenerates the mean orientation of the maximum horizontal stressin individual boreholes in ocean areas; and (3) to study themechanical responses of sediments and rocks in order tounderstand the nature of stress and stress paths that producedeformation of the ocean floor. The orientations of in-situ horizontal stresses weredetermined from analyses of borehole breakouts anddrilling-induced fractures (DIFs) as determined from four-armcaliper and Formation MicroScanner (FMS) data. Logging datawere analyzed using graphical and automated programs, usingbreakout and DIF criteria, directional statistics, and theborehole data were ranked according the WSM ranking system. Stress data from 44 oil wells and ODP boreholes in the NorthAtlantic Ocean represent important additions to the WSM fromareas where few stress data were available. Despite of theirrelatively shallow total depths, it is suggested that thestress orientation in many of the ODP boreholes are influencedby plate boundary forces. The observed variation in downholedistribution of breakouts in the oil wells and the lack ofregional trends indicate that local and regional stress sourcescontrol the stress field in these wells. Detailed laboratory stress measurements were conducted in atriaxial cell mounted in a servo-hydraulic load frame, usingreconsolidation and triaxial tests on small sub-samples fromtwo drill-core samples of different lithologies. Results from tests on a claystone from the basal section ofthe ocean-continent transition in West Iberia margin suggestthat the in-situ effective stresses are low because of the highpore pressure. The fractured nature of the underlying basementand breccia suggest that the pore fluids originate from deepersections. Results from tests on a calcarenite from about 1 kmdepth show that the elastic versus elastic-plastic behaviordiffers significantly, but that the rock behavior can bedescribed by critical state soil mechanics.

  • 200. Ask, Maria
    In-situ stress from breakouts in the Danish sector of the North Sea1997In: Marine and Petroleum Geology, ISSN 0264-8172, E-ISSN 1873-4073, Vol. 14, no 3, p. 231-243Article in journal (Refereed)
    Abstract [en]

    Borehole breakouts from 26 wells situated in the Danish Central Graben and one well situated in the northwestern section of the Ringkobing-Fyn High have been studied. The data provide information on the orientation of the contemporary principal horizontal stresses down to depths of 4.7 km. Statistics were used to obtain a mean azimuth of breakouts for each well, and each individual breakout was weighted by its length. Data quality of breakouts is assigned according to the World Stress Map quality ranking scheme. The breakout data reveal that SH orientations in the Danish Central Graben are extremely scattered; no regional trend in mean SH orientation can be identified as a result of the large standard deviation (±77°). Similar scatterings of SH orientations have been reported from adjacent regions of the North Sea. The results indicate that the state of stress in the sedimentary cover of the Danish Central Graben is influenced by a local stress generating mechanism rather than platewide stress transmissions mechanisms. Three units with different states of stress have been identified and found to correspond somewhat with the lithostratigraphic divisions of the Post Chalk Group, Chalk Group and Pre Chalk Group.

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