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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Estimations of Delay Costs caused by Roadworks

Wennström, Jonas January 2010 (has links)
When roadworks are performed, one of the impacts is delays in the traffic. Partly because of reduced speed limits past the work zones but mainly because of the facility's limited quality of service. This could result in significant delays for the road users with lost work and spare time as a consequence. The lost time in congestions could have been used more efficiently. It is therefore of interest to estimate these delays for different types of roadworks to calculate its macro economical impact. The estimations may be a factor in different types of planning, for example in roadwork planning, in work zone scheduling or in life cycle assessments. The estimations can be conducted using different methods, such as analytical, queuing theory or macrosimulation. However, to include the details of specific work zones an analysis method of higher detail is required. First to include varying geometric details, secondly due to the higher level of detail in the representation of the traffic. Therefore may microsimulation be a suitable analysis method. The purpose of this master thesis was to investigate microsimulations suitability for work zone analysis, by using the software AIMSUN. AIMSUN were different work zone types modeled, first of highways. Later was a 2-lane road modeled for which the traffic control was a fixed signal, then controlled by a simpler extension developed in C++ that simulated a flagger control. Using a developed helper program, the work zone models could be simulated for a large set of daily flow levels and heavy vehicle ratios. Together with corresponding results for normal conditions, it was possible to calculate the delays. The results were relationships between the total delays, for various heavy vehicle ratios. A concern with the results was deviations of the delays for different daily flows and heavy vehicle ratios. Even if the deviations will not have any greater impact on the total cost, they may be unwanted in decision models. Processing of the result may therefore be necessary. This master thesis has showed that microsimulation may be a suitable method to analyze work zone impacts. Using the high level of detail, work zones special character can be captured. Possible future work is to improve the reliability of results by performing validations of results with real work zone data to compare speeds, headways and queue lengths. Additional work may include to consider the diversion delays. / När vägarbeten utförs uppkommer fördröjningar i trafiken. Delvis på grund av reducerade hastigheter förbi arbetsområdet men i huvudsak på grund av minskad framkomlighet. Det kan resultera i betydande fördröjningar för trafikanterna med förlorad arbets- och fritid som följd.  Den förlorade tiden i köer kunde då ha använts effektivare. Det är då av intresse att kunna uppskatta fördröjningarna vid olika typer av vägarbeten för att beräkna dess samhällsekonomiska påverkan. Uppskattningarna kan då vara en faktor vid beslut inom olika typer av planering, till exempel vid vägarbetsplanering, schemaläggning eller livscykelanalyser. För att göra dessa uppskattningar kan olika metoder användas, till exempel analytiskt, med köteori eller makrosimulering. Men för att kunna inkludera detaljerna vid olika vägarbeten krävs en analysmetod med högre detaljnivå. Dels för att få med geometriska detaljer, dels detaljnivån i representation av trafiken. Då kan mikrosimulering vara en lämplig metod. Syftet med det här examensarbetat var att undersöka mikrosimulerings användbarhet vid vägarbetesanalyser, det genom att använda programvaran AIMSUN. I AIMSUN modellerades olika typer av vägarbeten, först för motorvägar. Sedan modellerades en 2-fältsväg där trafikkontrollen dels sköttes av en skyttelsignal, sedan utvecklades ett enklare tillägg i C++ som simulerade en flaggvakt som istället skötte trafikkontrollen. Med hjälp av ett utvecklat program kunde modellerna simuleras för en stor mängd olika dygnsflöden och andel tung trafik. Tillsammans med motsvarande grundscenario kunde fördröjningarna beräknas. Resultaten blev samband mellan totala fördröjningen under dagen beroende på dygnsflödet, det för olika andelar tung trafik. Ett bekymmer med resultaten var variationer i fördröjningarna mellan olika dygnsflödesnivåer och andelar tung trafik. Även om variationerna inte ger så stort utslag på totala kostnaden, så kan variationerna vara icke önskvärda i till exempel beslutsmodeller. En viss bearbetning av resultaten kan då vara nödvändig. Det här examensarbetet har visat att mikrosimulering kan vara en lämplig metod för att analysera vägarbetens påverkan. Med dess höga detaljnivå har vägarbetenas olika karaktär kunnat återskapas. Möjligt framtida arbete är att öka pålitligheten i resultaten genom validation med trafikdata från verkliga vägarbeten med jämförelser mellan hastigheter, avstånd och kölängder. Ytterligare arbete kan vara att uppskatta fördröjningar av att fordon väljer omvägar för att undvika vägarbetenas köer.
142

Kontroll för ökad kvalitet - mallar för kontrollplan-PBL, egenkontroll samt riskanalys

Hasselgren, Elin January 2011 (has links)
There are problems with poor quality, poor scheduling and poor working climate in the Swedish construction industry. Many parts have been involved, trying to solve the problem. This spring a new planning and building-law becomes final. In this law, the requirements set on the controls are greater. Hopefully this will lead to fewer construction errors. The requirements set on the working environment have also increased, forcing consultants and contractors to focus on safe workplaces. For each project requiring a building permit, an inspection plan has to been drawn. The inspection plan aims to ensure that the constructed building is operational. To ensure that the control plan is followed, self monitoring is performed. For each project, every designer also has to do a risk analysis to ensure a safe working environment. This report presents an investigation of stakeholders’ roles in the construction process. It also points out what by law should be controlled and against what. The result of the report is templates for control against PBL, self-monitoring plan and risk analysis. / Det finns stora problem med bristande kvalitet, dålig tidplanering och undermåligt arbetsmiljöklimat i den svenska byggbranschen. Detta problem är något som berörda parter lagt ner mycket tid på för att komma till rätta med. Som ett led i strävan mot kvalitetssäkring träder en ny Plan- och bygglag i kraft den 2 maj, som ökar kravet på innehåll i kontrollplaner, och därmed egenkontrollplaner. Arbetsmiljöfrågor har under senare år även de blivit mer aktuella med krav på byggarbetsmiljösamordnare och riskanalys. För samtliga projekt som kräver bygglov, rivningslov, marklov eller anmälan krävs en kontrollplan. Dessutom ska en egenkontrollplan samt en riskanalys finnas för samtliga projektörer i samtliga projekt. Riskanalyser ligger ofta till grund för val av lösningar eller omdirigeringar för att undvika personskador. I denna rapport redovisas en grundlig utredning av nyckelpersoners roll i kvalitets- och arbetsmiljöarbetet, samt vad som egentligen ska kontrolleras och mot vad. Nyckelpersonerna identifieras efterhand i rapporten. Resultatet av utredningen är förslag på utformning av mallar för kontrollplan-PBL, egenkontrollplan samt riskanalys.
143

Capacity assessment of arch bridges with backfill : Case of the old Årsta railway bridge

Andersson, Andreas January 2011 (has links)
The work presented in this thesis comprises the assessment of existing arch bridges with overlying backfill. The main objective is to estimate the load carrying capacity in ultimate limit state analysis. A case study of the old Årsta railway bridge is presented, serving as both the initiation and a direct application of the present research. The demand from the bridge owner is to extend the service life of the bridge by 50 years and increase the allowable axle load from 22.5 to 25 metric tonnes. The performed analyses show a great scatter in estimated load carrying capacity, depending on a large number of parameters. One of the factors of main impact is the backfill material, which may result a significant increase in load carrying capacity due to the interaction with the arch barrel. Based on theoretical analyses, extensive conditional assessments and the demand from the bridge owner, it was decided that the bridge needed to be strengthened. The author, in close collaboration with both the bridge owner and the persons performing the conditional assessment, performed the development of a suitable strengthening. The analyses showed a pronounced three-dimensional behaviour, calling for a design using non-linear finite element methods. Due to demands on full operability during strengthening, a scheme was developed to attenuate any decrease in load carrying capacity. The strengthening was accepted by the bridge owner and is currently under construction. It is planned to be finalised in 2012. The application of field measurements to determine the structural manner of action under serviceability loads are presented and have shown to be successful. Measured strain of the arch barrel due to passing train has been performed, both before, during and after strengthening. The results serve as input for model calibration and verification of the developed strengthening methods. The interaction of the backfill was not readily verified on the studied bridge and the strengthening was based on the assumption that both the backfill and the spandrel walls contributed as dead weight only. The finite element models are benchmarked using available experimental results in the literature, comprising masonry arch bridges with backfill loaded until failure. Good agreement is generally found if accounting for full interaction with the backfill. Similarly, accounting for the backfill as dead weight only, often results in a decrease in load carrying capacity by a factor 2 to 3. Still, several factors show a high impact on the estimated load carrying capacity, of which many are difficult to accurately assess. This suggests a conservative approach, although partial interaction of the backfill may still increase the load carrying capacity significantly. / Arbetet i föreliggande avhandling omfattar analyser av befintliga bågbroar med ovanliggande fyllning. Huvudsyftet är att uppskatta bärförmågan i brottgränstillstånd. En fallstudie av gamla Årstabron redovisas, vilken utgör både initieringen och en direkt tillämpning av föreliggande forskning. Kravet från broförvaltaren är att öka brons livslängd med 50 år, samtidigt som axellasten ska ökas från nuvarande 22.5 ton till 25 ton. Utförda analyser visar på stor spridning i uppskattad bärförmåga, beroende på ett stort antal parametrar. En av de främsta faktorerna är fyllningens egenskaper, vilken kan resultera i en markant ökning av bärförmågan p.g.a. samverkan med bågen. Baserat på teoretiska analyser, tillståndsbedömningar och krav från broförvaltaren beslutades att bron skulle förstärkas. En förstärkningsmetod har utvecklats i nära samarbete med broförvaltaren och personer som tidigare utfört tillståndsbedömningarna. Analyserna visar ett utpräglat tredimensionellt beteende, vilket har föranlett användandet av icke-linjära finita elementmetoder. Krav på full trafik under samtliga förstärkningsarbeten har resulterat i att dessa utförs enligt en föreskriven ordning, som ska reducera minskning i bär­förmåga under samtliga etapper. Förstärkningsförslaget godkändes av Banverket och är för närvarande under byggnation. Enligt plan ska dessa slutföras under 2012. Fältmätningar har använts för att bestämma det statiska verkningssättet under brukslaster, vilket visas ge goda resultat. Resulterande töjningar från passerande tåg har uppmäts i bågen, både före, under och efter förstärkning. Resultaten har använts både för att kalibrera beräkningsmodeller och att verifiera utförda förstärkningar. Samverkan mellan båge och fyllning har inte kunnat verifierats för den aktuella bron och de utvecklade förstärkningarna baseras på en modell där både fyllning och sidomurar endast utgör yttre verkande last. De framtagna finita element modellerna har jämförts med experimentella resultat från litteraturen, omfattande tegelvalvsbroar med ovan­liggande fyllning belastade till brott. Generellt erhålls god överensstämmelse om full samverkan mellan båge och fyllning antas. Om fyllningen istället endast betraktas som yttre last, minskar lastkapaciteten ofta med en faktor 2 till 3. Fortfarande uppvisar ett antal faktorer stor inverkan på bärförmågan, vilka ofta är svåra att med säkerhet bestämma. Ett konservativt betraktningssätt rekommenderas, även om delvis sam­verkan med fyllningen fortfarande kan öka bärförmågan avsevärt. / QC 20110426
144

Road Design for Future Maintenance : Life-cycle Cost Analyses for Road Barriers

Karim, Hawzheen January 2011 (has links)
The cost of a road construction over its service life is a function of design, quality of construction as well as maintenance strategies and operations. An optimal life-cycle cost for a road requires evaluations of the above mentioned components. Unfortunately, road designers often neglect a very important aspect, namely, the possibility to perform future maintenance activities. Focus is mainly directed towards other aspects such as investment costs, traffic safety, aesthetic appearance, regional development and environmental effects. This doctoral thesis presents the results of a research project aimed to increase consideration of road maintenance aspects in the planning and design process. The following subgoals were established: Identify the obstacles that prevent adequate consideration of future maintenance during the road planning and design process; and Examine optimisation of life-cycle costs as an approach towards increased efficiency during the road planning and design process. The research project started with a literature review aimed at evaluating the extent to which maintenance aspects are considered during road planning and design as an improvement potential for maintenance efficiency. Efforts made by road authorities to increase efficiency, especially maintenance efficiency, were evaluated. The results indicated that all the evaluated efforts had one thing in common, namely ignorance of the interrelationship between geometrical road design and maintenance as an effective tool to increase maintenance efficiency. Focus has mainly been on improving operating practises and maintenance procedures. This fact might also explain why some efforts to increase maintenance efficiency have been less successful. An investigation was conducted to identify the problems and difficulties, which obstruct due consideration of maintainability during the road planning and design process. A method called “Change Analysis” was used to analyse data collected during interviews with experts in road design and maintenance. The study indicated a complex combination of problems which result in inadequate consideration of maintenance aspects when planning and designing roads. The identified problems were classified into six categories: insufficient consulting, insufficient knowledge, regulations and specifications without consideration of maintenance aspects, insufficient planning and design activities, inadequate organisation and demands from other authorities. Several urgent needs for changes to eliminate these problems were identified. One of the problems identified in the above mentioned study as an obstacle for due consideration of maintenance aspects during road design was the absence of a model for calculating life-cycle costs for roads. Because of this lack of knowledge, the research project focused on implementing a new approach for calculating and analysing life-cycle costs for roads with emphasis on the relationship between road design and road maintainability. Road barriers were chosen as an example. The ambition is to develop this approach to cover other road components at a later stage. A study was conducted to quantify repair rates for barriers and associated repair costs as one of the major maintenance costs for road barriers. A method called “Case Study Research Method” was used to analyse the effect of several factors on barrier repairs costs, such as barrier type, road type, posted speed and seasonal effect. The analyses were based on documented data associated with 1625 repairs conducted in four different geographical regions in Sweden during 2006. A model for calculation of average repair costs per vehicle kilometres was created. Significant differences in the barrier repair costs were found between the studied barrier types. In another study, the injuries associated with road barrier collisions and the corresponding influencing factors were analysed. The analyses in this study were based on documented data from actual barrier collisions between 2005 and 2008 in Sweden. The result was used to calculate the cost for injuries associated with barrier collisions as a part of the socio-economic cost for road barriers. The results showed significant differences in the number of injuries associated with collisions with different barrier types. To calculate and analyse life-cycle costs for road barriers a new approach was developed based on a method called “Activity-based Life-cycle Costing”. By modelling uncertainties, the presented approach gives a possibility to identify and analyse factors crucial for optimising life-cycle costs. The study showed a great potential to increase road maintenance efficiency through road design. It also showed that road components with low investment costs might not be the best choice when including maintenance and socio-economic aspects. The difficulties and problems faced during the collection of data for calculating life-cycle costs for road barriers indicated a great need for improving current data collecting and archiving procedures. The research focused on Swedish road planning and design. However, the conclusions can be applied to other Nordic countries, where weather conditions and road design practices are similar. The general methodological approaches used in this research project may be applied also to other studies. / <p>QC 20110407</p>
145

Utformning av konst- och musikhus med läge i unik miljö / Designing a building intended for music and art and to be located in a unique environment

Thorvaldson, Niclas, Persson, Daniel January 2011 (has links)
Examensarbetets mål var att utforma två förslag på ett musik- och konsthus för placering i Växjösjön. Konstruktionen ämnas vara flytande och mobil.Gemensamt undersökte författarna byggnadens förutsättningar och möjligheter, i syfte att underlätta utformningsprocessen. Författarna utformade var sitt förslag. Det resulterade i två förslag med skilda arkitektoniska särdrag, skapade utifrån gemensamt stipulerade avgränsningar.Det ena förslaget är utformat med hjälp av geometriska former med raka sidor. Det kontrasterar mot det andra förslaget som har organiska och mjuka former. / The purpose of this thesis was to produce two alternative architectural designs, of a building, that will house various exhibitions and activities. Mainly those will be culture related; music and arts. The building is to be located in a Swedish lake, called Växjösjön, and the structure is intended to be placed on a floating hull.Initially the authors investigated, and discussed, what possibilities and limitations that were associated with the building. The authors then, separate from one another, created one alternative design each.The first of the two designs found its inspiration in different geometrical shapes, whereas the other was more of an organic design with a smooth and flowing architecture. / De digitala ritningarna finns att tillgå från författarna på begäran.
146

Infrastrukturförändringar och dess påverkan på den regionala utvecklingen : en studie av områden utmed E4 mellan Uppsala och Sundsvall

Godman, Brent January 2010 (has links)
Under efterkrigstiden har den regionala tillväxten i industriländerna undergått en explosionsartad utveckling. Samtidigt skedde en massiv utbyggnad och förbättring av infrastrukturen. Dessa båda områdes avancemang avslutades abrupt med den globala finanskrisen under 1970-talet. När konjunkturen vände tillbaka och tillväxten tog fart igen var det däremot inte med samma starka stäv som innan krisen. Denna tröga utveckling förbluffade makroekonomerna, som sökte med ljus och lyckta efter möjliga orsaker såsom energipriser, social reglering och regioners näringslivssammansättning. Det fick sin förklaring först när Aschauer bevisade att det fanns ett samband mellan minskade investeringar i infrastruktur i slutet av 1960-talet och en nedgång i den totala produktiviteten strax efteråt, vilket till viss del ledde till finanskrisen. Det har sedan dess publicerats en uppsjö av forskningsartiklar kring ämnet där den sammantagna slutsatsen är att det inte är frågan om infrastrukturen påverkar den regionala utvecklingen, utan till vilken grad, där transportinfrastrukturen anses ha störst betydelse.   Denna studie har som syfte att undersöka till vilken omfattning infrastrukturinvesteringar har på den kommunala och regionala utvecklingen längs europaväg 4 sträckning mellan Uppsala och Sundsvall. Dessutom undersöktes om man skulle kunna implementera alternativa finansieringsmetoder av vägutbyggnadsprojekt, eftersom dessa även skulle leda fram till en ökad regional utveckling. Studien genomfördes med hjälp av enkäter och intervjuer och ett bottom-up perspektiv, vilket möjliggjorde att de tidigare långsiktiga regionala utvecklingsmålen kunde analyseras.   Sammantaget har resultatet visat att studiens arbetsmetod har varit en bra undersökningsform, där gamla resultat bekräftats och nya slutsatser dragits. Analysen har påvisat skillnader bland kommuner och regioner i frågan om vilken omfattning infrastrukturförändringar har påverkat deras utveckling. Däremot ansåg samtliga tillfrågade att alternativa finansieringssätt, som ERUF och PPP borde användas, men att implementeringen skulle bli svår. / During the postwar period, there has been a tremendous variation in regional growth in developing countries. At the same time there was a massive expansion and improvement in infrastructure. The advances in these two areas ended abruptly with the global financial crisis in the 1970s. However, when times changed and the economy began to recover, it was not with the same momentum as prior to the crisis. This slow development stunned macro-economists, who searched high and low after possible causes such as energy prices, social regulations and the economic structure of different regions. It became clear only when Aschauer showed how the decline in infrastructure investment in the late 1960s resulted in a decline in overall productivity shortly afterwards, which, in part, led to the financial crisis. There have since been published a plethora of research articles on the subject in which the overall conclusion is that it is not an issue of whether infrastructure has an impact on regional development, but to what degree, and that the transport infrastructure is considered to be most significant. The aim of this study is to investigate of impact that infrastructure investments were considered to have upon municipal and regional development along the European route 4 between Uppsala and Sundsvall. In addition the possibilities of implementing alternative methods of financing road-building projects were also explored, as these would lead to greater regional development. The study was conducted using questionnaires and interviews and a bottom-up approach, which made it possible for the earlier long-term regional development objectives to be analysed.Overall, the results demonstrated that the method applied was a good way of conducting a survey, where old and new findings were confirmed. The analysis has revealed differences among municipalities and regions with regards to the impact that changes in infrastructure have on their development. On the other hand, the respondents were unanimous in believing that alternative funding methods, such as ERUF and Public-Private-Partnership should be used, but that they would be difficult to implement.

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