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  • 1.
    A. Taher, Ali
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology.
    BIM Software Capability and Interoperability Analysis: An analytical approach toward structural usage of BIM software (S-BIM)2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study focused on the structuralanalysis of BIM models. Different commercial software (Autodesk products and Rhinoceros)are presented through modelling and analysis of different structures with varying complexity,section properties, geometry, and material. Beside the commercial software, differentarchitectural and different tools for structural analysis are evaluated (dynamo, grasshopper,add-on tool, direct link, indirect link via IFC).

  • 2.
    Aagah, Orod
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Aryannejad, Siavash
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Dynamic analysis of soil-steel composite railway bridges: FE-modeling in Plaxis2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A soil-steel composite bridge is a structure comprised of corrugated steel plates, which are joined with bolted connections, enclosed in friction soil material on both sides and on the top. The surrounding friction soil material, or backfill, is applied in sequential steps, each step involving compaction of the soil, which is a necessity for the construction to accumulate the required bearing capacity. Soil-steel composite bridges are an attractive option as compared with other more customary bridge types, owing to the lower construction time and building cost involved. This is particularly true in cases where gaps in the form of minor watercourses, roads or railways must be bridged.

    The objective of this master thesis is the modelling of an existing soil-steel composite railway bridge in Märsta, Sweden with the finite element software Plaxis. A 3D model is created and calibrated for crown deflection against measurement data collected by the Division of Structural Engineering and Bridges of the Royal Institute of Technology (KTH) in Stockholm, Sweden.

    Once the 3D model is calibrated for deflection, two 2D models with different properties are created in much the same way. In model 1, the full axle load is used and the soil stiffness varied, and in model 2 the soil stiffness acquired in the 3D model is used and the external load varied. The results are compared to measurement data. In 2D model 1 an efficient width of 1,46 m for the soil stiffness is used in combination with the full axle load, and in 2D model 2 an efficient width of 2,85 m is used for the external load, in combination with the soil stiffness acquired in the 3D model.

    Aside from this, parametric studies are performed in order to analyse the effect of certain input parameters upon output results, and in order to analyse influence line lengths.

    Recreating the accelerations and stresses in the existing bridge using finite element models is complicated, and the results reflect this. Below are shown the discrepancies between model results and measurement data for the pipe crown. The scatter in the measurement data has not been taken into consideration for this; these specific numbers are valid only for one particular train passage.

    For crown deflection, the 3D model shows a discrepancy of 4%, 2D model 1 5% and 2D model 2 8% compared with measurement data. For crown acceleration, in the same order, the discrepancy with measurements is 1%, 71% and 21% for maximum acceleration, and 46%, 35% and 28% for minimum acceleration. For maximum crown tensile stress, the discrepancy is 95%, 263% and 13%. For maximum crown compressive stress, the discrepancy is 70%, 16% and 46%.

  • 3.
    Aagah, Orod
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Kardan, Caesar
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Ett tillgängligt och användarvänligt boende: Anpassningsmöjligheter för människor med rörelsehinder och nedsatt rörelseförmåga2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this paper we have theoretically built a house designed for people with impaired mobility. The

    essay begins with an introduction in which the purpose of the work, the methodology and the

    depth-research part is presented. Then the layout that explains how we intend to adapt the house

    for the demands detailed in the depth-research part is presented. In the same chapter various

    structural components, such as different floors and walls, are specified.

    In the selection of materials we have taken into account the criteria of our specialization and

    adaptation to the aesthetic aspects, where we evaluate materials based upon our wishes regarding

    technique and form. There are also other aspects that are important in the selection of materials,

    including that these are adapted to technical traits of the construction elements and installations.

    In a later chapter the technical installations such as ventilation systems, heating systems,

    electricity and sanitation are presented, where both technical and financial aspects are described

    in detail. The economic aspects are also described in connection with calculating the building's

    power and energy requirements and then presented in the section where costs are accounted for.

    Finally, the work is summarized in the section “Conclusion and Discussion” in which we analyze

    all the work, and based on these analyses conclusions are drawn. During the course of work

    regulations such as Boverkets Byggregler (BBR) and other sources were used. These sources are

    presented in the bibliography section. We also received help and guidance from our supervisors

    in various parts of the work, which we are grateful for.

  • 4.
    Aalto, Jonatan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Neuman, Elisabeth
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Comparison of Punching Shear Design Provisions for Flat Slabs2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Abstract

    A new generation of EN 1992-1-1 (2004) also known as Eurocode 2 is under development

    and currently there is a set of proposed provisions regarding section 6.4

    about punching shear, PT1prEN 1992-1-1(2017). It was of interest to compare the

    proposal with the current punching shear design provisions.

    The aim of this master thesis was to compare the punching shear resistance obtained

    in accordance with both design codes. Furthermore the eect of some parameters

    on the resistance was to be compared. It was also of interest to evaluate the userfriendliness

    of the proposal.

    In order to meet the aim, a case study of a real  at slab with drop panels was performed

    together with a parametric study of a pure ctive  at slab. The parametric

    study was performed for inner, edge and corner columns in the cases prestressed,

    without and with shear reinforcement.

    It was concluded that the distance

    av from the column axis to the contra  exural

    location has a big in uence on the punching shear resistance. The factor

    ddg

    considering concrete type and aggregate properties also has a big impact on the resistance.

    The simplied estimation of

    av according to 6.4.3(2) in PT1prEN 1992-1-1

    (2017) may be inaccurate in some cases.

    The length

    b0 of the control perimeter has a larger eect on the resistance in EN

    1992-1-1 (2004) than in PT1prEN 1992-1-1 (2017).

    In PT1prEN 1992-1-1 (2017), studs located outside the second row has no impact

    on the resistance.

    The tensioning force in a prestressed  at slab has a larger in uence on the resistance

    in PT1prEN 1992-1-1 (2017) than in EN 1992-1-1 (2004). Furthermore,

    the reinforcement ratio is increased by the tendons, and thus aect the resistance in

    PT1prEN 1992-1-1 (2017).

    Clearer provisions for the denition of the support strip

    bs for corners and ends

    of walls are needed in PT1prEN 1992-1-1 (2017).

    It may be questionable if the reduction of the perimeter for a large supported area in

    accordance with 6.4.2(4) in PT1prEN 1992-1-1 (2017) underestimates the resistance

    v

    in some cases.

    Considering the work-load with PT1prEN 1992-1-1 (2017), more parameters are

    included. However, they may not require that much eort to obtain.

    Keywords: Punching shear, resistance, concrete,  at slab, design provisions, Eurocode

    2, case study, parametric study, shear reinforcement, prestressed

    vi

  • 5.
    Abaid, Mohammed
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Land and Water Resources Engineering.
    Evaluation of Jatropha Curcas as future en-ergy crop in some African countries.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Biofuels now days consider as one of the successful alternative to meet the challenges associated with climate change and peak oil, as well as a way for poorer countries to develop an industry in order to enhance social and economic development. In many developing countries and particularly in Africa, this has led to large-scale investments in lands by foreign companies, and as a consequence there has been a debate on whether these actions are environmentally sustainable and whether this kind of activity actually brings economic development. The investments of biofuels in Africa, espe-cially the Jatropha plantations are debatable. Several arguments have been concentrat-ed on development goals, economic issues and environmental concerns. This report evaluates the status of some Jatropha projects in Sudan, Ethiopia, Kenya and Tanza-nia, the outcomes of the report show that biofuels from Jatropha lead to a significant socio -economic benefits by creating many jobs opportunities and improve the stand-ard of living in Africa. However, inadequate funding’s, high investment costs, no clear policies for biodiesel are the most challenging for Jatropha in Africa which need fur-ther mechanisms and ideology by African scientists, leaders, NGOs, farmers and deci-sion makers. In the studied countries, it was reported that the Jatropha produce low yields of oil seeds especially in the marginal lands with no enough water supplies. In Kenya the productivity of Jatropha is very low for large scale- project. Moreover some social and environmental impacts are also seen for Jatropha cultivations in Ethiopia, Kenya and Tanzania. Some Jatropha projects have impacted the food security nega-tively; nevertheless some biofuels experts believe that Jatropha has no any adverse im-pacts on food security since it is inedible and grown on marginal lands. In Ethiopia, the main environmental impacts of Jatropha are related to biodiversity, water quality and quantity. In Kenya, the environmental impacts are related to biodiversity, carbon emissions, water withdrawal, pollution of agro- chemicals usage, deforestation and soil erosion, whereas in Tanzania, the main environmental issues are connected to the change of land use system, impacts on biodiversity and impacts on water resources.

  • 6. Abate, M.
    et al.
    De Jong, Gerard
    KTH, School of Architecture and the Built Environment (ABE), Centres, Centre for Transport Studies, CTS.
    The optimal shipment size and truck size choice - The allocation of trucks across hauls2014In: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 59, 262-277 p.Article in journal (Refereed)
    Abstract [en]

    There has been a growing interest in understanding how firms allocate their trucks across hauls, and how this allocation changes under various economic environments. This study investigates how variations in route/haul, carrier and vehicle characteristics affect the optimal vehicle size choice and the associated choice of shipment size. We show that the two choices are derived from the same optimization problem. There can be a continuum of shipment sizes, but decision-makers in freight transport have to choose from a limited number of vehicle alternatives. Therefore, we use a discrete-continuous econometric model where shipment size is modeled as a continuous variable, and vehicle size/type choice as a discrete variable. The results indicate that when faced with higher demand, and during longer trips firms are more likely to use heavier vehicles and ship in larger quantities which suggest that firms are realizing economies of scale and economies of distance. The study also discusses the effect of vehicle operating cost on the vehicle selection process and its policy implications.

  • 7.
    Abbasi, Mazhar
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Dawit Ghebreigziabher, Kibret
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Objektklassificerad modellering och effektivisering avmängduttag2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The lack of fluent communication in the building industry has caught people’s attention because of

    time-based costs appearing in 2D and 3D modelling and takeoffs. These costs emerge in construction

    when miscommunication takes place between professionals in different projects.

    A research study of the subject has revealed the reason behind the current days’ miscommunication

    issues. The study shows that although the professionals tend to have an efficient way of working, the

    result isn’t very beneficial for the next man. Therefore a conclusion of the issue creates a demand for a

    mutual language in modelling and better softwares for takeoffs.

    This report’s results, with regards to optimization of modeling, has brought to light the use for the

    objectclassificationsystem BIP. These BIP-codes are used for branding objects in models of which the

    branding consists of unique codes. The code of every individual object has the purpose of being

    recognized by every project member and remain the same throughout the project.

    The proposal for the optimization of takeoffs is a software called VICO Office. The software contains

    well-advised methods for the import of models and close to automated takeoffs of these models.

    In conclusion, the study implies that there is sufficient motive to question the old ways of working and

    that light should be shed on new approaches. Technology and the industry face a constant change and

    the efficiency of current methods are never far away.

  • 8.
    Abbasi, Mozaffer
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Analys och implementering av VSL-System i FEM-Design för kontroll av stabiliserande effekt: En undersökning i syfte att fastlägga effekten av VSL-kablar i FEM-Design för att utvärdera dess stabiliserande påverkan.2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 9.
    Abbasi, Saeed
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Machine Elements.
    A study of nanostructured particles in railway tunnels2013Report (Other academic)
  • 10.
    Abbasiverki, Roghayeh
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Analysis of underground concrete pipelines subjected to seismic high-frequency loads2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Buried pipelines are tubular structures that are used for transportation of important liquid materials and gas in order to provide safety for human life. During an earthquake, imposed loads from soil deformations on concrete pipelines may cause severe damages, possibly causing disturbance in vital systems, such as cooling of nuclear power facilities. The high level of safety has caused a demand for reliable seismic analyses, also for structures built in the regions that have not traditionally been considered as highly seismically active. The focus in this study is on areas with seismic and geological conditions corresponding to those in Sweden and Northern Europe. Earthquakes in Sweden for regions with hard rock dominated by high-frequency ground vibrations, Propagation of such high-frequency waves through the rock mass and soil medium affect underground structures such as pipelines.

    The aim of this project is investigating parameters that affect response of buried pipelines due to high-frequency seismic excitations. The main focus of the study is on reinforced concrete pipelines. Steel pipelines are also studied for comparison purposes. The effects of water mass, burial depth, soil layer thickness and non-uniform ground thickness caused by inclined bedrock are studied. The results are compared to those obtained for low-frequency earthquakes and the relationship between strong ground motion parameters and pipelines response is investigated. It is shown that, especially for high frequency earthquake excitations, non-uniform ground thickness due to inclined bedrock significantly increase stresses in the pipelines. For the conditions studied, it is clear that high-frequency seismic excitation is less likely to cause damage to buried concrete pipelines. However, the main conclusion is that seismic analysis is motivated also for pipelines in high-frequency earthquake areas since local variation in the ground conditions can have a significant effect on the safety.

  • 11.
    Abbasiverki, Roghayeh
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Initial study on seismic analyses of concrete and embankment dams in Sweden2017Report (Other academic)
  • 12.
    Abbasiverki, Roghayeh
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Analysis of buried reinforced concrete pipelines subjected to seismic waves2014Conference paper (Refereed)
  • 13.
    Abbasiverki, Roghayeh
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Seismic response of buried concrete pipelines subjected to highfrequency earthquakesIn: Geotechnical and Geological Engineering, ISSN 0960-3182, E-ISSN 1573-1529Article in journal (Refereed)
    Abstract [en]

    Buried pipelines are tubular structures that cross large areas with different geological conditions. During an earthquake, imposed loads from soil deformations on concrete pipelines may cause severe damages. In this study, the use of two-dimensional finite element models of pipelines and surrounding soil for simulation of seismic waves that propagate from the bedrock through the soil are demonstrated. The models describe both longitudinal and transverse cross-sections of pipelines and the soil-pipe interaction is modelled as a nonlinear behaviour. The effects of uniform ground with different burial depths, soil layer thickness, soil stiffness and bedrock geometry on the seismic response of reinforced concrete pipelines is studied. Two earthquakes, with high and low frequency contents, are employed for the dynamic analysis. The results show that there is a much smaller risk of damage from high-frequency earthquakes, but that there is a significant effect on the response due to possible irregular ground with inclined bedrock.

  • 14.
    Abbasiverki, Roghayeh
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Malm, Richard
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Analysis of shallowly buried reinforced concrete pipelines subjected to earthquake loads2014In: Nordic Concrete Research, ISSN 0800-6377, no 51, 111-130 p.Article in journal (Refereed)
    Abstract [en]

    Buried reinforced concrete pipelines are widelyused in e.g. water and wastewater systems. Failure of these infrastructures mayresult in drastic effects and recently they have been brought into focus asvital components in safety systems for nuclear power installations. The highlevel of safety has here lead to a demand for reliable earthquake risk analyses.In this paper, methods are compared and the use of seismic design loadsdemonstrated. FE analysis in 2D of soil-pipe interaction under seismic wavepropagation is performed. The performance of concrete pipes subjected toseismic waves with different frequency content is evaluated with respect todifferent soil condition but also water mass effect.

  • 15.
    Abbaszadeh Shahri, Abbas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics. College of Civil Engineering, Roudehen branch, Islamic Azad University, Tehran, Iran.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Johansson, Fredrik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    CPT-SPT correlations using artificial neural network approach: A Case Study in Sweden2015In: The Electronic journal of geotechnical engineering, ISSN 1089-3032, E-ISSN 1089-3032, Vol. 20, no 28, 13439-13460 p.Article in journal (Refereed)
    Abstract [en]

    The correlation between Standard and Cone Penetration Tests (SPT and CPT) as two of the most used in-situ geotechnical tests is of practical interest in engineering designs. In this paper, new SPT-CPT correlations for southwest of Sweden are proposed and developed using an artificial neural networks (ANNs) approach. The influences of soil type, depth, cone tip resistance, sleeve friction, friction ratio and porewater pressure on obtained correlations has been taken into account in optimized ANN models to represent more comprehensive and accurate correlation functions. Moreover, the effect of particle mean grain size and fine content were investigated and discussed using graph analyses. The validation of ANN based correlations were tested using several statistical criteria and then compared to existing correlations in literature to quantify the uncertainty of the correlations. Using the sensitivity analyses, the most and least effective factors on CPT-SPT predictions were recognized and discussed. The results indicate the ability of ANN as an attractive alternative method regarding to conventional statistical analyses to develop CPT-SPT relations.

  • 16.
    Abbaszadeh Shahri, Abbas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Naderi, Shima
    Modified correlations to predict the shear wave velocity using piezocone penetration test data and geotechnical parameters: a case study in the southwest of Sweden2016In: INNOVATIVE INFRASTRUCTURE SOLUTIONS, ISSN 2364-4176, Vol. 1, no 1, UNSP 13Article in journal (Refereed)
    Abstract [en]

    Shear wave velocity (VS) is an important geotechnical characteristic for determining dynamic soil properties. When no direct measurements are available, V-S can be estimated based on correlations with common in situ tests, such as the piezocone penetration test (CPTu). In the current paper, three modified equations to predict the V-S of soft clays based on a comprehensive provided CPTu database and related geotechnical parameters for southwest of Sweden were presented. The performance of the obtained relations were examined and investigated by several statistical criteria as well as graph analyses. The best performance was observed by implementing of corrected cone tip resistance (q(t)) and pore pressure ratio (B-q) which directly can be found from CPTu data. The introduced modifications were developed and validated for available soft clays of the studied area in southwest of Sweden, and thus, their applicability for proper prediction in other areas with different characteristics should be controlled. However, the used method as a suitable tool can be employed to investigate.

  • 17.
    Abdali, Yasser
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Holm, Lovisa
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    En jämförelse mellan Tekla Structures och Civil 3D i krökta betongkonstruktioner2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Within the construction industry, there is a lot of discussion around BIM (Building InformationModelling). There is a need to move away from customized 2D-drawings and instead focus oninformative models which can be used throughout the whole cycle of construction. This developmenthas been ongoing within house construction, but this approach is harder to implement within thefacility sector.The difficulty in implementing a more BIM-oriented approach within construction is partly due tosoftware currently not being fully developed to create informative and reliable models of constructionswith complex geometries, such as bridges.Since Trafikverket, the largest construction developer within Sweden, has started to place a largerdemand on 3D there is a need for both technology and human resource to develop.The aim of this dissertation is to present a case study investigating the suitability of the software TeklaStructure and AutoCAD Civil 3D to perform a 3D-model of a double-curved bridge. The two pieces ofsoftware will be contrasted in a final comparison whereby both pros and cons will be presented.The study has made it clear that BIM is not just about creating an informative model, but it is alsoabout an approach which has the ability to completely change the construction sector to work morecollaboratively and effectively.The comparison between the two relevant software in this study shows that they both have strengthsand weaknesses and are suitable for our purpose. However, they differ in how detailed models theycan create and how well they have the ability to work with BIM to a greater extent.

  • 18. Abd-Alla, E. S. M .
    et al.
    Moriyoshi, A.
    Partl, Manfred
    EMPA, Swiss Federal Laboratories for Materials Testing and Research.
    Takahashi, K.
    Kondo, T.
    Tomoto, T.
    New wheel tracking test to analyze movements of aggregates in multi-layered asphalt specimens2006In: Journal of the Japan Petroleum Institute, ISSN 1346-8804, E-ISSN 1349-273X, Vol. 49, no 5, 274-279 p.Article in journal (Refereed)
    Abstract [en]

    This paper describes a new wheel tracking test for analyzing movements of aggregates in mixtures. The test device is conducted using as examples four-layered specimens taken from two Swiss national motorways, where severe rutting (G section) and longitudinal cracking (H section) were observed. This test method was developed by Moriyoshi. Tests can be carried out under temperature distributions similar to field situation. Two-dimensional movements and strains between aggregates for four-layered specimens due to the moving wheel loads were analyzed by right angle for direction of wheel pass. For this purpose, the cross section of the slabs with a width of 30 cm was divided optically into 5 vertical subsections. The transverse permanent surface deformations, the area changes in the transversal subsections as well as the maximum deformation of the surface and layer-interface through the centerline of the applied wheel load were determined. Strain distributions between aggregates in mixtures at high temperature (45 degrees C) under 600 passes were also measured by photo analysis. Test results show consolidation of the asphalt mixtures and material flow on the surface near the wheel load. The results also demonstrate that the aggregates (size of aggregate: 2 mm or larger) in each mixture move mainly in vertical direction. Large strains (40% or larger) between aggregates at summer condition were measured in the surface mixture near wheel track after 600 passes.

  • 19.
    Abdelmajid, Yezeed
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geodesy and Geoinformatics.
    Investigation and Comparison of 3D Laser Scanning Software Packages2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Laser scanning technologies has become an important tool in many engineering projects and applications. The output of laser measuring is the point cloud, which is processed in a way that makes it suitable for different applications. Processing of point cloud data is achieved through laser scanning software packages. Depending on the field of application, these packages have many different kinds of functions and methods that can be used. The main processing tasks used on a laser scanning software package include registration, modelling and texture mapping. Investigation and comparison of two laser scanning processing packages (Leica Cyclone and InnovMetric PolyWorks) are performed in this study. The theoretical and mathematical backgrounds of the above functions are presented and discussed. The available methods and functions used by each of the packages for these tasks are addressed and discussed. By using sample data, these functions are trailed and their results are compared and analyzed.

    The results from registration tests show the same results on both packages for the registration using target methods. Although, the results of cloud-to-cloud registration show some deviation from target registration results, they are more close to each other in both packages than to the target registration results. This indicates the efficiency of cloud-to-cloud methods in averaging the total registration error on all used points, unlike target registration methods.

    The modelling tests show more differences in the accuracy of generated models between the two packages. For both fitting and surface construction methods, PolyWorks showed better results and capabilities for three-dimensional modelling. As a result, the advantages and disadvantages of each package are presented in relation with the used task and methods, and a review of data exchange abilities is presented.

  • 20. Abderrazek, K.
    et al.
    Uheida, Abdusalam
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Seffen, M.
    Muhammed, Mamoun
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM.
    Srasra, N. Frini
    Srasra, E.
    Photocatalytic degradation of indigo carmine using [Zn-Al] LDH supported on PAN nanofibres2015In: Clay minerals, ISSN 0009-8558, E-ISSN 1471-8030, Vol. 50, no 2, 185-197 p.Article in journal (Refereed)
    Abstract [en]

    Zn-Al layered double hydroxides (LDH), before and after calcination, were tested for the removal of indigo carmine (IC) dye from solution. These LDH photocatalysts were characterized by powder x-ray diffraction (PXRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetry/differential thermogravimetry (TG/DTG), nitrogen physisorption at -196 degrees C, scanning electron microscopy (SEM) and diffuse reflectance spectrophotometry (DRS). The different photocatalysts were supported on polyacrylonitrile (PAN) nanofibres, so that filtration was unnecessary. The PXRD and FTIR analyses showed that the IC adsorption on c-Zn-Al-3-500 (LDH calcined at 500 degrees C) was enhanced by construction of the hydrotalcite matrix intercalated with the dye. The intercalation was clearly evidenced by the appearance of a peak at low degrees 2 theta values. All of the materials prepared exhibited photocatalytic activity, which for the c-Zn-Al-3-500 was comparable to that of commercial PAN-supported ZnO nanoparticles (100% degradation after 180 min). Kinetic studies showed that the degradation of the IC followed a pseudo-first order rate. The high activity and the ease of both synthesis and separation processes rendered this photocatalyst a promising candidate for environmental remediation.

  • 21.
    Abdi, Adel
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Efficient Winter Road Maintenance: A Study of Technical and Contractual Issues2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Since ancient times, roads have tied people and cultures together. Roads have been createdwith the aim of facilitating trade and cultural exchange among different regions in the world. After the technologic development in vehicle industry and dramatically increase of motoring in the world during the past century road communication has gained a great importance for transporting people and goods. Thus, good safety and accessibility on roads all year round is now a vital necessity for a healthy economy in all modern societies. In order to keep roads safe, available for use with high transport quality they need to be maintained in real time. One of the most difficult tasks in this context is to keep the roads in good condition and accessible even during winter. The main objective of this doctoral thesis is to attempt to specify the most efficient ways of executing winter road maintenance.  The preliminary issue in this context is whether it is the use of current assistive tools, that is, technical aspects that should be optimized and developed or whether it is the way in which winter maintenance services are procured and outsourced, that is, contractual aspects that should be improved which could give the optimal impact for both clients and contractors and make winter road maintenance more effective, or both issues. In order to define the outline of the research project a comprehensive state of the art survey was initiated with the intention of collecting and gaining insights into the earlier studies in the research area. Three basic areas associated with the performance of winter road maintenance were considered to be most relevant for review due to the anchorage between the areas. The selected areas were climatological, technical and contractual aspects. The literature review was followed by an electronic questionnaire survey. The results of the study in this stage showed that current technical methods almost functioned in a reasonable manner but there was an imprecise dissatisfaction with the current maintenance contract. The second stage of the research consisted of a number of additional empirical investigations in order to identify contractual problematic issues behind the current winter road maintenance in Sweden. Generally, those factors that are rarely considered as potential underlying causes to costly performance of winter road maintenance in Sweden were studied in this research project for example improper use of related technical assistive tools, procurement of improper bundled winter services and inappropriate contract structure. This thesis consists of six papers, five of which are related to each other, and the first one is completely independent but within research area. Findings in the thesis contributes to extend understanding about; how designing appropriate contracts can improve winter road maintenance, how proper use of assistive tools can reduce unnecessary winter road maintenance costs and minimize road traffic disruptions and delays, how a partnering structure in contracts can create confidence and trust between clients and contractors that in turn leads to minimizing or eliminating conflicts and disputes between parties involved, how choice of appropriate procurement methods through proper bundling of winter road services can contribute to shorten the procurement process and create incentives for contractors, and how selection of proper payment mechanisms can contribute to higher service quality of performed winter road measures. Additionally, an adequate knowledge and understanding of climate, proper knowledge of road weather and its impact on winter road traffic is essential for contribution of better planning of how to maintain the road network during winter. Since understanding about winter issues and its effect on winter road traffic is far from complete and winter road maintenance in the cold regions is a similar challenge, broad and complex, the results of this research may even contribute to improving winter maintenance problems in the countries with severe winters like Sweden.

  • 22.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Choice of Appropriate Tyres as an Asset to Traffic Safety on Winter Roads: Compilation and Evaluation of Some Winter Tyre Tests in Sweden2011In: International Journal of Civil & Environmental Engineering, ISSN 2077-1258, Vol. 11, no 6Article in journal (Refereed)
    Abstract [en]

    Winter tyres must be able to cope with the slipperiness which occurs on the surface of the roads during winter. The slipperiness is generated by water vapour in the atmosphere, precipitating and transforming into a solid form i.e. in ice form, either directly or after refrigeration or cooling. Many experimental studies e.g. winter tyre tests have been carried out by many companies and authorities independently from each other to determine if there are any types of tyres which have the best grip on different road surface conditions in the winter. The purpose of this study is to compile, analyse, compare and evaluate the obtained results of some winter tyre tests which have been performed in Sweden during years 2007-2010. The study aims further to find out which types of these tyres are most appropriate as an asset and increase the traffic safety on Swedish winter roads. Both studded tyres and non-studded tyres, socalled friction tyres or all season tyres were used in the tests. The method of the study is partly based on a theoretical study by reviewing some literature in this area and furthermore studying some practical cases i.e. winter tyre tests. The results of the tests are given in tables and figures showing the function of different types of the studded and nonstudded tyres on different road conditions. All test-tyres have been supplied by several tyre manufacturers. The study is only limited to compare the grip and effectiveness of different type of winter tyres on different kind of road conditions. The study does not take the impact of the tyres on the environment into consideration. The study shows that currently there are several types of winter tyres on the market but there is no tyre that is ideal or works best under all winter conditions.

  • 23.
    Abdi, Adel Hirmand
    KTH, School of Architecture and the Built Environment (ABE), Transportvetenskap, Väg- och banteknik.
    Contract forms and agreements for operation and maintenance of highways and railways during winter2011Report (Other academic)
  • 24.
    Abdi, Adel Hirmand
    KTH, School of Architecture and the Built Environment (ABE), Transportvetenskap, Väg- och banteknik.
    Key aspects in winter highway operation and maintenance2010Report (Other academic)
  • 25.
    Abdi, Adel Hirmand
    KTH, School of Architecture and the Built Environment (ABE), Transportvetenskap, Väg- och banteknik.
    Technical and contractual aspects in winter highway and railway operation and maintenance: a survey of current technical systems and contract forms in Sweden2011Licentiate thesis, comprehensive summary (Other academic)
  • 26.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Designing appropriate contracts for achieving efficient winter road and railway maintenance with high performance quality: A survey of the state of practice in Sweden2014In: International Journal of Quality and Service Sciences, ISSN 1756-669X, E-ISSN 1756-6703, Vol. 6, no 4, 399-415 p.Article in journal (Refereed)
    Abstract [en]

    Purpose - For a long time, the winter maintenance of the Swedish road and railway network had been performed in-house by Swedish Transport Administration, Swedish local authorities i.e. municipalities and Stockholm public transport. During the last 15 years the winter operation and maintenance of these state infrastructures have been performed by public procurement and contracting from independent contractors, where in practice the lowest price is the dominating selection criteria. The aim of this paper is to investigate and identify how these contracts are designed and how satisfied the parties are with the contract and the quality of the performed work during the winter and point our directions for improvement. Design/methodology/approach - The study was conducted by a literature review and followed by semi-structured interviews and electronic questionnaire. Findings - The results of the study which are based on the interviews and the online questionnaire show that there is widespread dissatisfaction with the contracts among both clients and contractors. Practical implications - The article prepares a basis showing how a contract affects the quality of the performed winter road and railway maintenance services. Originality/value - The findings lead to a number of suggestions about how to improve the contracts, e.g. having a separate winter maintenance contract to increase the quality of performed winter maintenance measures, a more partnering-like structure where consultations and adjustment can be made during the contract period. A partnering structure also makes it less important to get all the details right in the contract.

  • 27.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Effective Winter Highway Maintenance through Applicationof Partnering Concept2013In: International Journal of Engineering Management and Economics (IJEME), ISSN 1756-5154, E-ISSN 1756-5162, Vol. 3, no 3, 112-125 p.Article in journal (Refereed)
    Abstract [en]

    Inmany countries winter road maintenance is outsourced to private contractors. Selecting appropriate contract for performance of winter highway maintenance and implementing it in an efficient way is then very important for both results and costs. Writing contracts concerning winter road maintenance is however difficult as weather conditions are hard to describe in an exact way and as what is rational to do in a certain situation, depends on expected future conditions. Problems during recent harsh winters in Sweden have clearly illustrated this. The study argues, with reference both to theoretical and empirical studies, that a partnering concept can improve efficiency in outsourced winter road maintenance. A detailed model of how partnering can be implemented is presented for winter road maintenance contracts together with systems for information supply such as International Roughness Index –surface unevenness measurement and Road Weather Information System.

  • 28.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Payment mechanisms for winter road maintenance services2013In: Australasian Journal of Construction Economics and Building, ISSN 1835-6354, Vol. 13, no 4, 18-31 p.Article in journal (Refereed)
    Abstract [en]

    In countries with severe winters, a major portion of the annual budget for road maintenance is allocated to winter road maintenance. Thus it is important to identify an appropriate basis for the remuneration of the entrepreneurs who carry out the maintenance tasks, one that minimises or eliminates disputes and that satisfies both client organisations and contractors. The objective of this study is to investigate and evaluate the payment models applied in Sweden for winter road maintenance services and suggest possible improvements. Inadequate reimbursement models lead either to unnecessary cost overruns that affect the client's annual budget or cause cash flow problems for the contractor, which can result in safety issues. To solve the problems associated with paying for just-in-time road maintenance, cold region countries such as Sweden have developed various remuneration models, including some based on what is known as the Weather Index. The study uses a domestic questionnaire survey, analysis of a number of current contract documents, a series of meetings with project managers followed by an international benchmarking investigation. The study identified four winter maintenance remuneration models of which one is based on weather data. The study reveals that the payment model based on weather data statistics is applied only to roads with higher traffic flow and generates the most uncertainty about costs. Possible improvements should include more reliable weather data obtained from weather stations and bonuses related to customer satisfaction.

  • 29.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Public Procurement of Winter Road Maintenance Services Based on EU Procurement Directive: Lessons from Sweden2013In: Journal of Investment and Management, ISSN 2328-7721, Vol. 2, no 4, 70-86 p.Article in journal (Refereed)
    Abstract [en]

    Public procurement of road maintenance services, particularly in cold regions is not an easy task in order to satisfy road-users during winter. Road-users’ dissatisfaction, complaint and pressure can usually be considered as major factors for having more accessible and safe roads during winter. These pressures have contributed and led to an increasing critical approach focusing on public procurement of these services after some harsh winters in the recent years in Sweden with traffic disruption and delay as consequence i.e. an increasing focus on the way in which the Swedish state authorities and local governments procure winter road maintenance services. The present study which is part of a larger research project investigating efficient winter road maintenance through procurement, tendering and contract aimed at extending this knowledge base with regard to procurement and socioeconomic factors with focus on the winter maintenance of the Swedish road network. The study reveals that even the Swedish winter road maintenance services are procured and outsourced in accordance with EU directive and public procurement rules transposed into the Swedish act on public procurement, the act has been interpreted in a manner that all the process has led to great dissatisfaction of end-users during winter due to improper bundling of winter related services. The lack of economic motivation in current contracts concerning winter road maintenance in the form of incentives has led to an inefficient performance of winter road measures. The study suggests a number of proposals in order to make forthcoming contracts more effective through proper bundling of winter services and create incentives for contractors to improve the performance of winter road maintenance services.

  • 30.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management, Building and Real Estate Economics.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Use of Road Weather Information System (RWIS) as Assistive Tool for Effective Winter Road Maintenance: Technical andContractual Interactions2012In: International Journal of Engineering and Technolgy, ISSN 2049-3444, Vol. 2, no 12, 2002-2012 p.Article in journal (Refereed)
    Abstract [en]

    Winter highway operation and maintenance in the northern periphery is a challenge, a broad and complex area. Understanding about this area and its effect on winter traffic performance is far from complete. During the last forty years since Swedish Transport Administration (former Swedish National Road Administration) began attempting of the use of Road Weather Information System -RWIS on the Swedish road network, the repair and maintenance methods of this assistive tool has dramatically changed. Changing of the methods have been due to the progress and development of the technology within this area i.e. from simple stations that could be connected via telephone network for icy road warning to amore sophisticated and modern internet based technology. The main objective of this study was to investigate and find the importance and effectiveness of using weather data collected from RWIS by road agencies as an assistive tool for effective performance of winter road maintenance, and how these tools are currently maintained without influencing the delay of winter road maintenance.The study also attempts to find possible interactions between technical and contractual issues that may affect winter road maintenance. The method of the study was partly based on a theoretical study by reviewing some internationally published articles and reports in this area and furthermore a domestic questionnaire survey, an internationalbenchmarking and a follow-up study within a selected region in Sweden. The results of the study reveal that even if the weather stations are normally placed on roads where the risk of icy roads is greatest, there are indirect factors which influence the planned maintenance of these tools which subsequenly cause delay of winter road maintenance.

  • 31.
    Abdinasser, Ahmed
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Tabatabaei, Sara
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Samverkan av jord och ovanliggande struktur i FEM-program: En studie av nya jordmodeller I FE-programmet 3D- Structure2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    De senaste åren har det funnits olika företag som har tillverkat avancerade mjukvaror inom byggbranschen. En del av mjukvaror är avsedd att skapa 2D ritningar och 3D modeller. Med hjälp av dessa verktyg har ingenjörer och arkitekter snabbt och enkelt skapat ritningar och modeller för projektering av konstruktioner. Utvecklingen inom detta område kallas BIM. Byggnadsinformationsmodellering, BIM, stödjer design av en byggnad genom alla faser och möjliggör bättre konstruktions-, tillverknings- och inköpsaktiviteter.

    Andra mjukvaror är tilltänkt att förutse hur en struktur reagerar på verkliga laster, vibrationer, värme och andra fysiska effekter. För detta används finita elementmetod, där kommer strukturen analyseras i element för ett noggrannare resultat. En utveckling inom detta område har också skett. Företaget Strusoft AB utvecklar FE-verktyg för analys av struktur. Den senaste nyheten är modul för beräkning av samverkan mellan struktur, grundläggning och undergrunden i form av jord. Modulen kallas 3D-Soil och används enligt Strusoft för modellering och analys av geokonstruktioner.

    I denna rapport redovisas modellering av en struktur och underliggande jord med finit elementanalysprogrammet, FEM-Design som är försett med den nya modulen 3D-Soil för geotekniska beräkningar.

    Målet är att jämföra resultat för moment utifrån samverkanskrafter mellan jord och struktur i FEM-Design med ett annat FEM-program, Lusas. Till skillnad från FEM-Design appliceras jord- och vattentryck som utbredd last i Lusas.

    Resultaten visar att det finns signifikanta skillnader mellan resultaten från analysprogrammen och det finns begränsningar i modelleringsverktyget som behöver utvecklas vidare.

  • 32.
    Abdu, Mohammed
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Ullén, Philip
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Dimensionerande vattenförbrukning och dess variationer2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sweden, 2010, approximately 907 million cubic meters of drinking water was withdrawn from municipalities. All of this water must be transported, which is done through water pipes. To dimension these it requires that we know how much water that is to be distributed and it varies among others depending on the time of the day, week and year that the withdrawals occur. In today’s approach of designing new water pipes, amongst other ways, we use typical examples of consumption variations during the day of a similar area. In addition, arbitrary and experiential values of ‘ratio of peak hour to average day’ and ‘ratio of peak hour to average hour’ are used.

    Unfortunately today’s way of dimensioning water pipes has not been ensured due to inadequate detailed data on consumption quantity. The main purpose of this study is to confirm or refute today’s way of dimensioning water pipes.

    To verify this we have with detailed data from Norrvatten been able to see consumption quantity on an hourly basis which helps us assess today’s dimensioning process. By measuring the flow into 13 municipalities and then comparing them against each other regarding population size, distribution over categories of users and more, we have been able to get different dimensioning factors.

    In this report we can conclude that there is a need to update the factors regarding ‘ratio of peak hour to average day’ and ‘ratio of peak hour to average hour’. In order to further study the dimensioning factors, a system must be developed that can measure the precise consumer flow for different consumer categories on a more detailed level.

  • 33.
    Abdul Al, Fatima
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Alla barns lekplats: En studie om tillgängligheten på lekplatser2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Sweden is one of the leading countries when it comes to availability in the physical environment. Approximately 7 000 children in Sweden are disabled. Half of these children use a wheelchair. It is every child’s right to play, and it’s thereby interesting to know whether every child is given the opportunity to use a playground. In the county of Helsingborg there are playgrounds appealing to many children, although the question is whether every child is given the chance to play at these playgrounds.

    The aim of this study is to highlight the importance of availability at playgrounds and outline ways to improve the availability. The method used in this thesis is a literature study, focusing on legal framework and literature about availability, usability and playgrounds. The case study provides information about eight playgrounds in Helsingborg. There is also an interview with landscape architect Johanna Elgström.

    Playgrounds where availability has been prioritized are often more available and useable for wheelchair-bound children. Still, the legal framework is in need of a more precise definition of availability and usability to ensure that playgrounds are suitable for children using a wheelchair. The playgrounds that are more available and useable can favor children using a wheelchair and give them the opportunity to socially interact with other children.

  • 34.
    Abdulbaki, Mohammad
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Mammar Chaouche, Abdelah
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Användning av flygaska i vattenbyggnadsbetong 2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Engineering Concrete is used as a collective term for concrete structures related to the hydropower plants, dams and heavier plants. With great success, concrete has been used for a very long time for these types of structures. These constructions make high demands on the concrete quality and construction design as they are expected to have a lifetime of a hundred years or more.

     

    In casting such concrete is exposed to a temperature which can lead to cracking of the newly cast structure. Because the temperature rise is the primary cause of cracking, you can use various methods to reduce this. An effective way to reduce the temperature rise is to try to keep the cement content in the concrete as low as possible, because at the adiabatic conditions may say that the total temperature rise is directly proportional to the cement content in the concrete. An effective way to reduce the temperature rise is to use out some fly ash instead of cement. Fly ash is a powder mass obtained in the production of electricity and heat in coal-fired plants and cogeneration plants. Fly ash is a puzzolanic material which means that it reacts with calcium hydroxide and water, and can thus partially replace cement clinker.

     

    The purpose of this report is to provide a better understanding of how the fly ash affecting hydraulic concrete. By reading this report you will get at first a basic knowledge of what the concrete, hydraulic concrete and fly ash are. Furthermore, the section that dealt with the cracking of the hydraulic concrete, general knowledge followed out causes and remedies. A comparison has been made between a typical water building structural component, with and without fly ash. What has been compared are how the construction affected with and without fly ash on strength, resistance and the risk of cracking. Furthermore, the temperature dot calculations performed with the program HACON. The purpose of the calculations was to show how the different parameters with and without fly ash affects the risk of cracking of a typical hydraulic structures.

     

    The result of the temperature calculations show that you get a lower temperature development in a monolith cast with the fly ash and the construction cements compared to a monolith molded with construction cement without fly ash. With the reduced temperature development arose lower tensions in the flyashmonolith. In the survey carried out in this report, the results show that there is tension that exceeds the tensile strength of the monolith without fly ash and thereby bursting the structure. The monolith examined with fly ash as crackreducing action occurs tensile stresses which are lower than the tensile strength and thus does not crack structure. The results show that the cracking in a typical hydraulic structures can be reduced with fly ash.

  • 35.
    Abdulkadir, Hesho
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Kostov, Andrey Petrov
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Studie om energibesparing på OKQ8 i Häggvik samt andra energieffektiviserade byggnader2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The report begins with a brief description of some of the most common measures for energy savings in buildings with recess in the solar collectors and photovoltaic panels which lays a solid foundation for our study. Next comes the main part of the study consisting of detailed descriptions of three of the top streamlined Swedish buildings.

    The main purpose of this study is to investigate some of the energy efficiency improvements done on the OKQ8’s gasoline station in Häggvik with a calculate part. Part of the task is to calculate how many photovoltaic cell panels should be installed in order to cover the whole buildings energy need. After that have we calculated the payback time and profitability of some of the installations at the petrol station. We have also studied other energy optimized buildings and compared their specific energy need with that of OKQ8.

  • 36.
    Abdulla, Nardien
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Ali, Mohammed
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering.
    Ett modernare sätt att dimensionera: En jämförelse för Huvudstaprojektet, FEM-design eller handberäkning ?2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This theses has been conducted in collaboration with Peab where the students had Tomas Schäfer and Peter Jansson as supervisors.

    This report addresses how a specific secondary build up, located in Huvudsta Centrum, could had been designed differently. The original frame was designed with the old BKR construction rules. But at the construction start a new construction standard was applied, the Eurocode. Therefore, the house got decreased in weight to meet the stricter Eurocode requirements.

    The current frame was designed using manual methods, which were compared with the results from the same frame calculated with a computer programme, FEM-Design 3D Structure. The report is based on the know-how of how a designer should proceed to join the production model and the analytical model. This to be able to designed in a BIM environment.

    The difference in results, between the two methods, was about 50% reeducation in purchased steel and about 40% in design-engineer costs. We have estimated a total saving of 141000 SEK for Peab.

  • 37.
    Abdulrahman, Keiwan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Potrus, Fadi
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Numerical analysis and model updating of a steel-concrete composite bridge: Parametric study & Statistical evaluation2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the year 2006, only 10 years after the steel- concrete composite bridge, Vårby bridge was built, fatigue cracks were found during an inspection. To further investigate the reasons and the potential danger of the cracks, an investigation under the commission of the Swedish Transport Administration was issued in 2009. After the detection of fatigue cracks, several measurements were carried out in order to monitor the static behavior by the use of strain gauges at selected positions along the bridge. The measurements from the strain gauges monitoring the global behavior were then used to calibrate an finite element model.

     

    The present report is part of the research of understanding the behavior of steel-concrete composite bridges. Numerical analysis and model updating have been used in order to understand and determine how different parameters affects the strain range and the global behavior. The numerical analysis and parameter study were performed in the Finite Element software Abaqus and programming language Python. The outcome of the parameter study was then used to perform the model updating by the method of falsification in MATLAB.

     

    The results from the parameter study and the model updating showed that the measured strains could be reached with a wide range of parameter combinations. Even with unreasonable parameter values, the measured strains were obtained. To investigate the reason for this, a multiple linear regression analysis was performed which showed that the strain range is strongly correlated to the Young’s modulus of steel and concrete and also to the connector elasticity, which resembles the studs in the real bridge.

     

    Two different finite element models, with two completely different input parameter values, obtain the same strain range for the global behavior. It is therefore not certain to assume that a model is accurate and valid based on the fact that the predicted strain range from the finite element model is close to the measured strain range since the global behavior of a steel- concrete composite bridge can be modeled by many different sets of parameters.

  • 38.
    Abed, Mohamad Samir
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Hosseinzade, Azita
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Parameterstyrd projektering av broar: Koppling mellan Rhinoceros-Grasshopper och Tekla Structures2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    New methods for project designing in the building construction industry have been developed by introducing modern and powerful BIM tools. Several of today’s constructions are designed according to three-dimensional principles.Tekla Structures is a powerful BIM tool that is capable of managing both house and infrastructure constructions. Despite this, the program cannot handle bridges with a horizontal and vertical curvature efficiently. The designers must instead rely on several other applications to manage complex bridge constructions.In order to use the advantages of Tekla Structures, the software needs to be evolved or complimented by other third party softwares. This project aims to integrate new working technics and introduce a method based on parametric design in Tekla Structures. Such form of modeling enables the modification of parameters to a desired model for the user.A script is created through a visual programming extension that generates a parametric based bridge models. The bridge type in this project was designed, is an integral bridge.The project has proved that parametric based design is more effectively and a solution to manage bridges with horizontal and vertical curvature.

  • 39.
    Abedini, Pegah
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Lag 2010:879 om allmännyttiga kommunala bostadsaktiebolag: Hur den implementerats av aktörerna2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bakgrund:

    Den första januari 2011 trädde lagen om allmännyttiga kommunala bostadsaktiebolag i kraft. Dess ändamål var att jämställa konkurrensen sinsemellan de privata fastighetsägarna och de allmännyttiga kommunala bostadaktiebolagen. Lagen yrkade främst på att de allmännyttiga kommunala bostadsaktiebolagen skulle agera mer affärsmässigt för att konkurrensen inte skulle snedvridas. Kommunen som ägare var bland annat tvungen att ställa tydligare krav på bolagen genom att ta ut marknadsmässiga borgensavgifter och låneräntor samt ställa marknadsmässiga avkastningskrav.

    Frågan är nu hur de allmännyttiga kommunala bostadsaktiebolagen agerat utifrån dessa nya förutsättningar sedan lagen trädde i kraft den 1 januari 2011. Uppsatsen syftar till att undersöka hur den nya lagen om allmännyttiga kommunala bostadsaktiebolag har implementerats av aktörerna på bostadshyresmarknaden. Målet med uppsatsen är att klarlägga konsekvenserna av lagen för aktörerna på bostadshyresmarknaden, tydliggöra dess implikationer för beslutsfattare i de kommunala bostadsaktiebolagen samt kunna ge kommunerna bättre underlag i besluten rörande sina bolag.

    Metod:

    Enkätstudie där vd:ar från allmännyttiga kommunala bostadsaktiebolag har tillfrågats angående bolagets och kommunens agerande och inställning sedan lagen ikraftträdde.

    Avgränsning:

    Enkätstudien har avgränsats till att omfatta vd:ar på kommunala bostadsaktiebolag i Sverige, rörande händelser som inträffat sedan den 1 januari 2011. Vd:ar på bolag belägna i Stockholms Län, Uppsala län, Södermanlands Län, Östergötlands Län, Jönköpings Län samt Västra Götalands Län har medverkat i enkäten.

    Resultat och slutsats:

    De kommunala allmännyttiga bostadsaktiebolagen instämmer allmänt i att de agerar mer affärsmässigt sedan den nya lagen introducerades. Avkastningskraven i ägardirektiven har setts över, och de kommunala borgens– och ränteavgifterna har generellt sett ökat sedan lagen trädde i kraft.

  • 40.
    Abela, Eric
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Qattan, Nessrin
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Transaktioner på den kommersiella fastighetsmarknaden 2011: Trender och fallstudier2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med detta examensarbete är att kartlägga några av de största transaktionerna på den svenska fastighetsmarknaden under 2011. Detta år har kännetecknats av lägre transaktionsvolym än föregående år, bland annat på grund av ett osäkrare ekonomiskt läge.

    Teorin har sin utgångspunkt i vilka aktörer som finns på marknaden och vilken roll konsulten, utländska investerare och banker spelar samt hur utvecklingen av fastighetstransaktions marknaden i Sverige sett ut fram tills idag. Kartläggningen har gjorts på sätt att försöka få med de flesta typer av aktörer och utreda varje transaktion för sig samt ge en närmare analys av dessa.

    Kartläggningen visar att de största transaktionerna i Sverige under 2011 gjordes av både noterade och onoterade fastighetsbolag på köpsidan, samt onoterade fastighetsbolag på säljsidan.

    Att döma av fjolårets utveckling marknadsmässigt pekar en hel del på att den kraftiga tillväxten i Sverige kommer att leda till mer arbetstillfällen, med fallande vakanser och stigande hyror som konsekvens på den svenska fastighetsmarknaden.

  • 41.
    Abhijeet, Kumar
    KTH, School of Architecture and the Built Environment (ABE), Land and Water Resources Engineering (moved 20130630).
    Governing water pollution effectively: A comparative study of legal frameworks & their implementation in India & Sweden.2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Case studies from India have shown that the legal regime governing water pollution control in India has miserably failed. Sectoral approach to water management is quite evident. On the other hand Sweden has shown a remarkable change with regard to environment management. The poor management of a resource makes the resource further poor. Thus effective management of the resources becomes crucial. Good governance has been vital in conservation of a resource. But the issue is what constitutes good governance with respect to water? Law has always played a steering role in governance aspect. But despite having pollution control laws the effective governance of water pollution has not been attainable in India. Are the pollution control laws fundamentally wrong or some other factors prevail which is beyond the reach of law to control the pollution problem. The thesis which is a comparative study of legal framework and their implementation in India and Sweden attempts to explore how control of water pollution has been effectively governed in Sweden and what needs to been done in India.

  • 42.
    Abid, Muhammad
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.). Högskolan i Gävle, Sweden.
    Bengtsson, Lars
    Dabhilkar, Mandar
    Factors affecting shifts in global supply chain networks: A configurational approach2013In: Proceedings of the 20th International Annual EurOMA conference, Dublin, Ireland, 9-12 June 2013, 2013, 2013Conference paper (Refereed)
    Abstract [en]

    In certain situations, global companies strive to take advantage of short-term changes in economic and exchange rates on the never-ending journey of competitiveness. This paper seeks to extend Ferdows’s (2008) production network models by adding the factors affecting shifts between rooted and footloose network configurations. Two companies were selected in order to illustrate the models and reveal other possible factors. The identified factors are differentiated in terms of configuration and coordination and merged in a matrix. The trends and implications on global supply chains are also discussed.

  • 43.
    Aboudi, U
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Fluid and Climate Technology.
    Altaie, K
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Fluid and Climate Technology.
    Solvärme i krypgrunder2009Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 44.
    Aboudi, Ula
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Fluid and Climate Technology.
    Altaie, Kenan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Fluid and Climate Technology.
    Solvärme för krypgrunder2008Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 45.
    Aboutalebi, Ghareman
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Optimering av fackverksstolpar med konisk eller parallell form2005Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 46.
    Abramsson, Marcus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Brygiewicz, Alexander
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Partnering - Kundnytta i fokus2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The literature and research is limited in the subject costumer value in partnering projects. This contributed to the interest to perform an empirical study on the topic. It has not been shown to be appropriate to implement this on a specific issue or problem, when the available information deals with the theory and applications of partnering, not customer value.

    Given the above problem this papers purpose is to describe how the various contractors and clients, associated with partnering activities in Sweden, experiencing the work and factors that maximize customer value in a partnering project.

    A qualitative method where six people were interviewed, related to partnering activities in Sweden. The interviews are semi-structured and adapted to each interviewee.

    The most important conclusions that answer the purpose are:

     Understand the customers business

     Choose a form of compensation based on founded trust and project type

     All parties combined knowledge provides the right conditions for the customer to make the right decision

     Lack of common well-developed digital tools

     Make decisions at the right time

     Reference Surfaces and own final checks instead third party inspector

  • 47.
    Abrigian, Mari
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Almqvist Gärtner, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Möjligheter och utmaningar med internationella inköp: En studie av internationella inköp2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The construction industry in Sweden today are facing a major challenge in building society and following the pace of population growth. Rising material prices are today a fact, and at the same time there is a lack of capacity at the Swedish suppliers as they are bound up in supplier agreements for the coming years. The largest construction companies in Sweden have been working strategically with international suppliers for a long time to increase their margins and to secure their material needs.

    BTH Bygg AB is today a company that builds, renovates and maintains real estate in Stockholm. The company has expanded in recent years and is committed to strong growth by 2020. Work on international purchasing has previously been limited to BTH Bygg, but this type of purchase is today seen as a necessity to continued growth and to be competitive in that part of Sweden where most is built.

    The purpose of this study is to analyze BTH Bygg's existing purchasing process to further develop and propose improvements with international procurement as a starting point.

    The study has been conducted with the help of interviews to get a complete picture of the issues of international purchasing. BTH Bygg AB has a strong organization with a lot of experience related to the subject area, and focus has been on compiling these in order to come up with suggestions and ideas on how to handle international purchases. Recommendations are focused on areas related to supplier assessment, communication, logistics and product selection.

  • 48.
    Abshirini, Ehsan
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Interaction between rivers and morphology of cities in Sweden2014In: Our common future in urban morphology, Porto: FEUP edições (Faculdade de Engenharia da Universidade do Porto Edicoes), 2014Conference paper (Refereed)
    Abstract [en]

    Rivers as one of the most important topographic factor have played a strategic role not only on the appearance of cities but they also affect the structure and morphology of cities. In this paper I intend to find out the influence of rivers on the morphology of a cities and discuss that how a city in its physical network interacts with a river flowing inside. My study area is river-cities in Sweden in which they have not received much attention in this issue. To this purpose I use space syntax method integrating with geospatial analysis and extract the properties of physical form of cities in terms of global and local integration value, choice value and so on. Comparing the states of presence and absence of rivers in these cities as well as evaluating the effect of rivers on the morphology of areas located in different banks of rivers are also part of interest in this paper. The primary result shows that although a river is not comparable to a city based on size and the area occupied by, it has a significant effect on the form of a city in both global and local properties. In addition, tracking the pattern of river-cities and their interaction to rivers may lead us to interoperate the physical form of these cities in terms of structured and distributed cities.

  • 49.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture, Architectural Design.
    Resilience, space syntax and spatialinterfaces: The case of river cities2017In: A|Z ITU Journal of the Faculty of Architecture, ISSN 1303-7005, Vol. 14, no 1, 25-41 p.Article in journal (Refereed)
    Abstract [en]

    Resilience defined as the capacity of a system to manage impacts, keep its efficiency and continue its development has been scrutinized by researchers from different points of view over the past decades. Due to the prominence of resilience in urban planning, this paper intends to find out how the spatial structure of cities deals with disturbances, and if geographical phenomena such as rivers affect the resilience in cities. Using the space syntax methods syntactically analyze the resilience in cities, we innovatively introduce two measures; similarity and sameness. These measures are in relation with the syntactical properties of cities and compare the degree of resilience between different groups. Similarity measures the degree to which each city retains the relative magnitude of its foreground network after a disturbance and sameness is the degree to which each city retains the same segments as its foreground network after a disturbance. Likewise to network resilience studies, we apply different disturbances on cities and explore the reaction of cities to disturbances in terms of size of the foreground network and which segments are parts thereof. We then compare different groups based on these measurements as a method to analyze sameness and similarity. The results show that the resilience, in the way we define it, is different in different cities depending on in which view and based on which parameters we are discussing the resilience. Additionally morphological phenomena such as rivers have a great impact on the structure of cities and in turn on their resilience.

  • 50.
    Abshirini, Ehsan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Geoinformatics.
    Koch, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Rivers as integration devices in cities2016In: City, Territory and Architecture, ISSN 0885-7024, E-ISSN 2195-2701, Vol. 3, no 1, 1-21 p.Article in journal (Refereed)
    Abstract [en]

    Background: As dynamic systems rivers and cities have been in interaction under changing relations over time, and the morphology of many cities has risen through a long and steady struggle between the city functions and the river system flowing inside. This makes river cities an interesting case to study how the presence of geographical features interacts with spatial morphology in the formation of cities.

    Methods: The basis of this research is enabled by utilizing a novel model for cross-city comparison presented by Hillier in his Santiago keynote in 2012 called a “star model”. This is done on large samples of cities investigating concurrent configurations, as well as how the properties in this star model react to specific forms of disturbance.

    Results: Results illustrate that the foreground network as identified through maximum choice values in cities are more vital to the structure of cities than the bridges. The overall syntactic structure tends to retain its character (degree of distributedness) and the location of its foreground network (which street segments constitute the foreground network) even when bridges are targeted. Furthermore, counter to the initial hypothesis, river cities tend to change less than non-river cities after targeted disturbance of the systems. Finally, the results show that while there is a statistical morphological difference between river cities and non-river cities, this difference is not directly explained through the bridges.

    Conclusion: Integrating space syntax with statistical and geospatial analysis can throw light on the way in which the properties of city networks and urban structure reflect the relative effect of rivers on the morphology of river cities. The paper, finally, contributes through offering one piece of a better perception of the structure of river-cities that can support strategies of river-cities interaction as well as enhance our knowledge on the constraints and limits to that interaction.

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