| 11. |
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| 12. |
- Plos, Mario, 1963, et al.
(författare)
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Structural assessment of concrete railway bridges
- 2008
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Ingår i: Bridge Maintenance, Safety, Management, Healt Monitoring and Informatics. - 9780415468442 ; , s. 705-
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Konferensbidrag (refereegranskat)abstract
- The work presented provides enhanced assessment methods that are able to prove higher load-carrying capacities and longer fatigue lives for existing concrete railway bridges. It was performed as a part of the EU-project Sustainable Bridges. The results are implemented in the Guideline for Load and Resistance Assessment of existing European Railway Bridges, see SB-LRA (2007) and are reported in detail in a background document, see SB4.5 (2007). The work presents improved methods for the determination of in-situ material properties, for deterministic as well as probabilistic assessments. Advanced methods for structural analysis are presented, e.g. regarding combined shear, torsion and bending interaction. Recommendations are given regarding redistribution of sectional moments and forces obtained from linear finite element analysis. One main objective was to facilitate the use of non-linear analysis for structural assessment. This provides the greatest potential to discover any additional sources for load-carrying capacity, and gives a better understanding of the structural response. Another main objective was to provide methods to assess the remaining structural resistance of deteriorated concrete bridges. Recommendations are given on the effect of corrosion and a methodology is presented for assessment of remaining fatigue life, with emphasis on short-span bridges and secondary elements.
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| 13. |
- Bankvall, Claes, 1942, et al.
(författare)
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Air transport in and through the building envelope
- 2004
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Ingår i: Thermal Performance of the Exterior Envelopes of Whole Buildings. - 2166-8469.
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Konferensbidrag (refereegranskat)abstract
- A national R&D program dealing with air transport in and through the building envelope is presented, including some overviews of results. The program develops predictive models for evaluating air movements in and through the building envelope. These models are coupled to the outside climate and pressure situation and to the inside climate through the interaction with models defining the building services system. A major aim of the program is to analyze problems of relevance to the building process. This includes site inventory, modeling of typical situations, and laboratory testing for input data and to validate the models. The objective is to develop tools to help design and evaluate building elements and to give the necessary foundation for estimating the convective transport of heat and moisture in the envelope, which is decisive for the indoor climate, the consumption of energy, and the durability of the construction. The research program is ongoing and this presentation is to invite communication with others.
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| 14. |
- Sasic Kalagasidis, Angela, 1968
(författare)
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The whole model validation for HAM-Tools—case study: Hygrothermal conditions in a cold attic under different ventilation regimes
- 2004
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Ingår i: Thermal Performance of the Exterior Envelopes of Whole Buildings. - 2166-8469.
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Konferensbidrag (refereegranskat)abstract
- HAM-Tools is a software library specially constructed for hygrothermal system analysis in building physics. The software is developed as a modular structure of standard building elements and systems using a graphical programming environment. Due to its modular structure and transparency, each of the existing components can be easily changed and adjusted to specific user demands. In order to asses the software’s ability to predict the building hygrothermal response under given climatic and operating conditions, validation tests against measurements have been performed. As a case study, temperature and relative humidity of a cold ventilated attic space in real operating conditions was selected. Validation results are presented as a comparison between measurements and calculations. Parametric sensitivity analyses were performed and necessary adjustments for the missing input parameters have been fully documented. The code has shown a high degree of reliability, both in a qualitative and a quantitative way.
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| 15. |
- Ask, Daniel
(författare)
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Measurement-related uncertainties in overcoring data at the Aspo HRL, Sweden. Part 2 : Biaxial tests of CSIRO HI overcore samples
- 2006
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Ingår i: International Journal of Rock Mechanics And Mining Sciences. - : Elsevier BV. - 1365-1609 .- 1873-4545. ; 43:1, s. 127-138
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Tidskriftsartikel (refereegranskat)abstract
- This paper is the second dealing with measurement-related uncertainties of overcoring data undertaken at the Aspo Hard Rock Laboratory and focuses on the biaxial test data from CSIRO HI overcore samples. The first paper dealt with measurement-related uncertainties in connection with the overcoring phase [1]. The uncertainties identified in connection to biaxial tests of CSIRO HI overcore samples include too large applied pressures and poor sampling frequency. At the Aspo HRL, the results yield that most overcore samples fractured during biaxial testing, meaning that a significant part, 56%, of available strain gauge combinations were removed from calculations of the elastic parameters. Remaining strain gauge combinations indicate average values of 62 +/- 5 GPa for Young's modulus and 0.25 +/- 0.01 for Poisson's ratio, which are considerably lower than previously published values [2-5], and are in good agreement with results from biaxial tests on Borre Probe overcore samples [6-10]. The stress calculations were obtained from re-analyzed elastic parameters and strains, and show primarily a reduction in stress magnitudes. Overall, the stress field obtained with different stress measurement methods and its variation with depth is now quite well resolved. The overcoring data suggest that the principal stresses are inclined with a vertical component dipping about 65 degrees from the horizontal over the investigated rock volume (140-420 m depth). This is interpreted as a result of influence from the sub-vertical NE-2 Fracture Zone that divides the stress data into two stress domains [11], although it may also be an artefact because the sigma(2)- and sigma(3)-magnitudes are of the same order of magnitude.
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| 16. |
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| 17. |
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| 18. |
- Hallberg, Daniel, et al.
(författare)
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Långsiktig underhållsplanering av fjärrvärmenät : en förstudie av möjligheter till utveckling av LMS
- 2007
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Rapport (populärvet., debatt m.m.)abstract
- Samtidigt som fjärrvärme är ett effektivt sätt att leverera värme så leder en centraliserad värmeproduktion till att fler personer drabbas vid eventuella driftavbrott. Detta skapar ett behov av ökad leveranssäkerhet och kontroll av prestanda över hela fjärrvärmenätets livscykel. Genom en långsiktig planering av nätets utbyggnad och förvaltning erhålls effektivare resursanvändande och större säkerhetsmarginaler. Långsiktig planering bygger till stor del på analys av olika scenarier där såväl rådande förutsättningar som ”worst cases” kan beaktas utifrån olika aspekter (tekniska, ekonomiska, säkerhetsmässiga m.m.). Målet är att hitta optimerade åtgärder, vilket kräver systematisk hantering och bearbetning av en stor mängd information. Detta kan endast göras rationellt med hjälp av IT-verktyg. Life cycle Management System (LMS) är ett resultat av tre konsekutiva EU-finansierade forskningsprojekt där gruppen för byggnadsmaterialteknik – Högskolan i Gävle, har haft en ledande roll. Systemet innehåller utvecklade rutiner och metoder för hantering av information som ligger till grund för långsiktig planering och optimerad förvaltning av byggnadsverk. Systemmässigt är LMS uppbyggt av moduler som hanterar och analyserar data på olika sätt. Anledningen till systemets modulbaserade struktur är att det, helt eller i delar, kan anpassas mot de krav och önskemål som klienten ställer på systemet. På så sätt behöver klienten bara komplettera sitt befintliga system med de funktioner som önskas av LMS, samtidigt som denne undviker att ”kasta ut” det gamla systemet. Förstudien omfattar en litteraturstudie och analys av Gävle Energi AB:s (GEAB) drift- och underhållsdata. Förstudiens syfte är att identifiera och kartlägga de anpassnings- och utvecklingsbehov som föreligger en implementering av LMS som planeringsverktyg för GEAB:s fjärrvärmenät.
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| 19. |
- Hinnerson, Josefina, 1972
(författare)
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Att bygga för vård. Lokalförsörjning inom vårdbyggnadssektorn
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Organisations and the activities they perform are changing continuously as a consequence of organisational and technological development. In order to effectively support a core activity its premises must be able to adapt to this development. Therefore changes are being sought regarding current praxis with issues concerning strategies and processes for the provision of premises. What is strived for is a process open for the client and user that are not primarily focused on construction but rather on the function and usability for the core business. Within the healthcare sector, where this study has been carried out, one is continually faced with changes related to organisational, medical and technological aspects. In order to accommodate these changes rapid adaptations of the premises are required, and a process that can handle rapid changes needs to be developed. However, it is not only the process that needs to be developed, the organisation carrying out the process of provision of premises must also develop to meet new demands on transparency, development of knowledge and efficiency.Through a case study and action research projects it has been investigated how an organisation providing facilities to the health care sector can develop and meet the challenges put on it. The research question was structured in two parts. The first question concerned how the process of providing premises is influenced by the structure of the organisation. The second question concerned what aspects could be identified to describe the interaction between core activities, the organisation being supplied with facilities, and the organisation that provide, supply, the facilities.Findings indicated that there are three aspects in the interaction that influence the result of a premise providing project. These are the process, the actors and the structure of the organisation.The process is important because it is the facility providers’, the actors, tool when they carry out their tasks. Process descriptions should therefore be appropriate and be used in a way so that it helps the actors to achieve the goals for the projects. Shared process descriptions can coordinate and transfer experience and knowledge between projects. On an organisational level, coordination and structure is also supporting the knowledge transfer. The structure of the organisation is therefore an important aspect and directly related to the first research question concerning how organisational structure influence the process of provision of facilities Findings from the case study also indicated that the actors behaviour was central in order to establish an effective interaction between the organisation providing facilities an their clients.
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| 20. |
- Malmgren, Lars, et al.
(författare)
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The excavation disturbed zone (EDZ) at Kiirunavaara mine, Sweden - by seismic measurements
- 2007
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Ingår i: Journal of Applied Geophysics. - : Elsevier BV. - 0926-9851 .- 1879-1859. ; 61:1, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- The presence of an excavation disturbed zone (EDZ) around an excavation boundary can significantly affect the overall performance of the excavation and the general safety of men and equipment. Hence, it has been an important subject of research in various rock excavation projects. The EDZ is generally defined as the rock zone beyond the excavation boundary where the physical, mechanical and hydraulic properties of the rock have been significantly affected due to the excavation and redistribution of stresses. For LKAB's Kiirunavaara underground iron ore mine in Sweden, the understanding of the EDZ is essential for optimal design of rock support. With this main objective an EDZ investigation was conducted at the mine using seismic measurement techniques. Cross-hole seismics and spectral analyses of surfaces waves (SASW) were the main techniques used. Borehole Image Processing Systems (BIDS) complemented the seismic measurements. The results show that an EDZ with a thickness of 0.5-1.0 m existed behind the boundaries of the mining drifts being investigated. The magnitude of the Young's modulus of this zone was 50% to 90% of that of the undisturbed rock.
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