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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.
111

Vägskador av tung trafik : Upplåtande av vägnätet för 74-tons lastbilar. / Road damage due to heavy vehicles. : Introducing 74-ton trucks on the road system.

Lundberg, Kevin, Gonzales, Elkin January 2016 (has links)
No description available.
112

Pavement Response to Moving Loads

Khavassefat, Parisa January 2014 (has links)
The response of flexible pavements at vehicle-road interaction has been studied in this thesis. A quasi-static and a dynamic framework for analysing the pavement structure under moving load has been developed. Both frameworks are general, robust and computationally efficient. The quasi-static procedure is based on superposition principle and is computationally favourable, as it requires only reduced incremental problem to be solved numerically. Using the developed framework the effect of vehicle configuration and traffic characteristics on the damage induced in pavements is investigated numerically. It is shown that the developed numerical model provides a more accurate explanation of different distress modes. Moreover the conventional analysis and design methods with layered linear elastic behaviour assumption for asphalt layer are unable to capture several important aspects of pavement response. In the dynamic analysis approach the pavement roughness and vehicle suspension system is linked to a dynamic pavement model in order to account for the dynamic effects at vehicle-road interaction on pavement response. A finite element method is relied upon in order to establish the response function for a linear viscoelastic pavement structure with dynamic effects taken into account. The computational procedure developed is applied to evaluate the effect of the pavement surface roughness on the pavement structure response to truck traffic loading. Stress field parameters governing fracture initiation in asphalt layers are reported for two measured road roughness profiles. It is shown that the dynamic effects at vehicle-road interaction may have a profound influence on the stresses induced in flexible pavements; therefore these effects need to be taken into account for accurate prediction of the road performance in the field. / <p>QC 20140516</p>
113

Möjligheter och utmaningar för ökad användning av miljövänlig betong i anläggningsprojekt

Hamid Garakani, Sasha, Karlsson, Måns January 2022 (has links)
Reducing carbon dioxide emissions is one of the biggest and most important tasks in modern times in the world. Sweden has a national climate target that net emissions of carbon dioxide should be zero by 2045. Construction projects in Sweden account for approximately 8% of total emissions, where concrete is one of the building components with the largest emissions. Concrete is one of the world's most widely used building materials and accounts for approximately 43 percent of emissions in the construction industry. In order to reduce emissions and for Sweden to reach the climate goals by 2045, a change in the current use of concrete is required. One measure could be for the construction industry to use more environmentally friendly concrete with less carbon dioxide emissions. Increased use of environmentally friendly concrete can contribute to a change in the construction industry for a reduction in carbon dioxide emissions. The purpose of the study is that the work will investigate what challenges there are in implementing environmentally friendly concrete and that the study will propose what measures are required to promote the use of environmentally friendly concrete for contractors in construction projects. The aim of the study is to develop challenges and potential measures to promote the implementation of environmentally friendly concrete in the construction industry for contractors. In order to be able to answer the purpose, the following research questions have formed the basis of the study:     1. What are the challenges for construction contractors to increase the use of         environmentally friendly concrete in construction projects?     2. What measures are required to promote increased use of environmentally         friendly concrete in future construction projects? The study is based on an interview study with respondents who work with the implementation of environmentally friendly concrete in some way. The interview study consisted of nine respondents whose roles were project manager, client and concrete researcher. That the study is based on an interview study that has interviewed people with different roles in the construction industry was to broaden the study to get more perspectives on challenges and measures with the use of environmentally friendly concrete. The challenges that have emerged in the study of implementing environmentally friendly concrete in construction projects are limited regulations, time aspect, dependence on key people, internal communication, uncertainty in deliveries and rumours in the construction industry. Based on the challenges, four different measures have been presented to promote the use of environmentally friendly concrete. The four measures are that time planning should take place earlier in the process, focus more clearly on feedback on environmental aspects, more organization-driven projects on environmental choice and to introduce a budget for innovation solutions in the construction industry. Environmentally friendly concrete is constantly being developed and the study must be relevant even when the development of environmentally friendly concrete has progressed further. The regulations in the construction industry affect all the challenges and measures presented in the study. In order to be able to approach net zero emissions from concrete in the construction industry, updated regulations are required that call for change and innovations. / concrete, implementing, increase, challenges
114

Surveying with GPS, total station and terresterial laser scaner: a comparative study

Chekole, Solomon Dargie January 2014 (has links)
No description available.
115

Wetland Landscapes: Exploring Marsh Refrains in Norfolk County, Ontario

Gignac, Emma 20 May 2022 (has links)
Southern Ontario is an exciting place to study our relationship with wetland landscapes, as almost 75% of these ecosystems have been transformed and seized for urban or agricultural development, although the rate of wetland loss may recently be decreasing (Ontario Ministry of Natural Resources and Forestry, 2017; Ontario Biodiversity Council, 2015). This thesis is constructed around fieldwork conducted in Norfolk County during the late summer of 2020 and extensive engagement with various marsh complexes within the region. This research aims to present a more holistic understanding of our current relationship with wetland environments in Southern Ontario. This includes situating the wetland landscapes of Norfolk County within the infrastructures of the local Great Lakes region and the global and affective entanglements of the Anthropocene. Additionally, we explore certain co-constitutive present-day relationships that approximate people to wetland refrains. Finally, this research highlights the political intricacies of wetland management. Through this work, I will describe the complexities of these environments and demonstrate how being attuned to wetland landscape temporalities may be the best way to reterritorialize the wetland landscape.
116

Byggandet av vägar - Tillämpning av mindre avvikelse från detaljplan / Construction of Roads - Application of Minor Deviation from Detailed Development Plan

Badi, Marwan January 2020 (has links)
Ekerö kommun är en kommun i Stockholms län. kommunen utarbetar bindande detaljplaneroch besluter hur vägarna får bebyggas. När ett vägprojekt väl ska utföras ochöverensstämma med planen uppstår ofta avvikelser.Syftet med detta arbete är att ta reda på varför dessa avvikelser i stor utsträckning uppstårav Ekerö kommuns vägprojekt och vad som kan göras för att mildra eller undvika dessaproblem. För att kunna svara på de framtagna frågeställningarna har arbetet baserats påstudier av facklitteratur. Därefter har det genomförts intervjuer med några personer inomoch utanför Ekerö kommun. Under intervjuerna diskuterades problematiken samt hur kanden lösas på bästa möjliga sätt.Examensarbetet behandlar en väg byggt i Ekerö kommun, Fredriksstrandsvägen som harundersökts genom arbetet för att upplysa problemet.Främsta anledningen bakom avvikelser är att vägen inte byggs upp med standarder ochriktlinjer som fastställts i publicerade föreskrifter från Trafikverket. Det har konstrueratsäven att bakomliggande orsaker till dessa avvikelser kan vara bristande planering,otillräckliga arbetsberedningar, mänskliga orsaker, kunskaps- och kommunikationsbrister.För en effektiv avvikelsehantering bör kommunen utföra vissa metoder, såsom detaljrikplanering, bygg med kvalité, samarbetsrutiner och viktigast att tillämpa vägstandarder vidprojektering. / Ekerö Municipality is a municipality in Stockholm County. the municipality prepares bindingdetailed plans and decides how the roads may be built. When a road project is to be carriedout and in accordance with the plan, deviations often occur.The purpose of this work is to find out why these deviations are to a large extent arisingfrom the Ekerö municipality's road project and what can be done to mitigate or avoid theseproblems. To answer the questions developed, the work has been based on studies ofprofessional literature. Subsequently, interviews were conducted with some people insideand outside Ekerö municipality. During the interviews, the problem was discussed and how itcan be solved in the best possible way.The thesis deals with a road built in Ekerö municipality, Fredriksstrandsvägen, which hasbeen investigated through the work to inform the problem.The main reason for deviations is that the road is not built up with standards and guidelineslaid down in published regulations from the Swedish Transport Administration. It has alsobeen constructed that the underlying causes of these deviations may be lack of planning,inadequate work preparations, human causes, knowledge, and communication deficiencies.For efficient deviation management, the municipality should carry out certain methods, suchas detailed planning, building with quality, collaboration routines and most importantlyapplying road standards when planning.
117

Improved Driver Support in Smart Cities to Reduce the Environmental Impact of Trucks : Designing a concept for 2030

Walfridsson, Alida January 2021 (has links)
The transport industry is a key contributor to carbon dioxide emissions and climate change and heavy-duty vehicles are responsible for a quarter of the emissions from road transport in the EU. One way of reducing the energy consumption of a truck is improving driving skills by minimizing breaking for example. When cities become smarter using information and communication technologies more data is available regarding the traffic situation which can be used to give the driver more information to make better driving decisions. The aim of the study is to identify and formulate how a Scania truck will guide a driver in a smart city with the goal to reduce the environmental impact.  The method used was the double diamond design process model with the four phases discover, define, develop and deliver. Discovering was done through interviewing personnel from the Swedish Transport Administration and Stockholm municipality which set the technological possibilities for the smart city Stockholm in 2030. In the define phase drivers were interviewed and three functions were chosen to proceed with further for a concept: traffic lights, intersections and bus lanes. Both drivers and experts were consulted in the develop phase before completing the final concept in the deliver phase.  The results show that the smart city Stockholm in 2030 will have a more dynamic traffic situation that the driver will have to adapt to. Experienced drivers will not be able to choose the best route and optimize speed without using the new information shared by the city. The result is a concept with the new information presented using a Head-Up Display (HUD) which puts the information in the drivers view range. Information shared in the HUD includes, time to green for traffic lights, warning for approaching vehicles from out of sight streets in intersections, access to bus lanes and recommended speed for intersections and traffic lights to avoid unnecessary stops.
118

Capturing Engineering Knowledge : Concepts of Automation in Bridge Design

Van Gompel, Benoît January 2018 (has links)
In this thesis, the aim was to create an automation platform for bridge design using knowledge-based engineering (KBE) concepts. More specifically, the focus was put on the ultimate limit state design of reinforced concrete bridge columns. Compared to other engineering industries like manufacturing, the construction in- dustry only has a limited degree of automation, even though technically feasible automation already exist. This thesis proposes an automation framework, which has been developed using the object-oriented programming (OOP) paradigm in python. The platform employs a general piece of geometric logic on which a section analysis module is based that can analyse the normal force and two bending moments around mutually orthogonal axes in a reinforced concrete section of a column. The geometric logic is constructed out of six OOP classes, that are able to define a reinforced concrete section, and out of a set of three more OOP classes, that define the material parameters. The section analysis tool is based on the computation of limit surfaces for reinforced concrete sections. From these limit surfaces, interaction diagrams have been derived by taking plane sections of the limit surface. The verification of the automation application has been done by comparing in- teraction diagrams from the literature with interaction diagrams produced by the automation application. The comparison showed that both results coincided, taking into account some simplifications. Additionally, the automation framework is thought to be suitable for fulfilling a data management role in the design process, which is worthwhile to further investigate upon. The automation application can be further improved by augmenting the existing analysis modules with modules for other reinforced concrete elements or other construction materials.
119

AUTOMATISERAD PROJEKTERING : MODELLERING OCH BERÄKNING AV EN STÖDMUR I GRASSHOPPER, KARAMBA OCH TEKLA STRUCTURES / AUTOMATED DESIGN : MODELING AND CALCULATION OF A RETAINING WALL IN GRASSHOPPER, KARAMBA AND TEKLA STRUCTURES

Lythell, Markus, T. S. Jarjes, Wesam January 2018 (has links)
Många av dagens konstruktioner som projekteras är välkända och beprövade standardkonstruktioner. Projekteringsmetodiken för dessa är tidskrävande och repetitivt då projekteringen alltid påbörjas från grunden.  Detta ineffektiva arbetssätt anses kunna ersättas med en effektivare metod och därmed möjliggöra ett bättre nyttjande av resurser. Denna skulle kunna ersätta de repetitiva delmoment i projekteringen så dessa utförs per automatik. Metoden kan även utnyttja effektiviteten som återfinns i parametriskt styrda modeller och de välutvecklade beräkningssätt som idag används.  Undersökningen av detta har skett genom en sammankoppling av ett flertal processer och mjukvaror och med en automatiserad projekteringsmetod förmodas stora tidsbesparingar vara möjliga, vilket resultatet av detta arbete tyder på.
120

A comparison between emergency ventilation systems semi-transvers ventilation and natural ventilation in Road Tunnel A

Jerräng Carlstedt, Ludwig January 2017 (has links)
No description available.

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