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  • 301.
    Barnes, David L.
    et al.
    University of Alaska, Fairbanks.
    Cosden, Elizabeth
    Fairbanks Environmental Service.
    Johnson, Bryan
    Fairbanks Environmental Service.
    Johnson, Karol
    Fairbanks Environmental Service.
    Stjärnström, Stina
    Luleå tekniska universitet.
    Johansson, Karin
    Luleå tekniska universitet.
    Filler, Dennis M.
    Shannon and Wilson, Inc..
    Operation of soil vapor extraction in cold climates2002In: Cold regions engineering: cold regions impacts on transportation and infrastructure : proceedings of the eleventh international conference, May 20-22, 2002, Anchorage, Alaska / [ed] Kelly S. Merrill, New York: American Society of Civil Engineers (ASCE), 2002, p. 956-967Conference paper (Refereed)
    Abstract [en]

    Soil Vapor Extraction has proven to be a viable method for reducing the mass of volatile compounds from soils that have been impacted by contamination. The theory, design and use of SVE systems have been fairly well documented, however the use of SVE systems in cold environments such as Alaska has not been adequately investigated to date. This paper examines the use of SVE systems in cold environments. The affect of low soil temperatures on volatile compound removal by SVE is discussed. Methods used to overcome the impact low temperatures have on the operation and effectiveness of SVE systems are examined in detail. Possible low cost strategies such as barometric pumping during winter months are presented as solutions to reducing SVE operating costs in cold regions

  • 302. Bastani, Mehrdad
    et al.
    Persson, Lena
    Löfroth, Hjördis
    Swedish Geotechnical Institute.
    Smith, Colby A
    Schälin, David
    Swedish Geotechnical Institute.
    Analysis of ground geophysical, airborne TEM, and geotechnical data for mapping quick clays in Sweden2017In: Landslides in sensitive clays: From research to implementation / [ed] Thakur, V, L'Heureux, JS, Locat, A, Cham: Springer , 2017, p. 463-474Chapter in book (Refereed)
    Abstract [en]

    Airborne transient electromagnetic (ATEM) data for mapping clay areas are acquired in four areas in Sweden. The resistivity models from the inversions of ATEM data are compared to the existing geotechnical, geological and ground geophysical data in one of the areas at Slumpån located in the Göta River valley. The ATEM models reveal information about layering and thickness of the sediments, the river depth and bedrock undulations. The estimated resistivities at the known locations of quick clays are within the range of 8-40 ohmm. The variation is dependent on the type of the surrounding sediments and the leaching process. The resistivity models have a limited resolution and must always be integrated with geotechnical and geological information for a confident and precise interpretation that leads to a realistic model. The method can be utilized as an effective tool prior to planning of any detailed and costly ground geotechnical investigations.

  • 303. Belfrage, J
    Horisontalarmerade fyllningar på lös jord1981Report (Other academic)
  • 304.
    Bellopede, Rossana
    et al.
    Polytechnic University of Turin, Italy.
    Castelletto, Eleonora
    Polytechnic University of Turin, Italy.
    Schouenborg, Björn
    RISE, SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Marini, Paola
    Polytechnic University of Turin, Italy.
    Assessment of the European Standard for the determination of resistance of marble to thermal and moisture cycles: recommendations for improvements2016In: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 75, no 11, article id 946Article in journal (Refereed)
    Abstract [en]

    The bowing phenomenon is so relevant that two projects, EU funded, from 1999 studied it and a European Standard to assess the resistance to thermal and moisture cycles (influencing bowing) has been recently adopted. In particular, according EN 16306: 2013, measurements of bowing and flexural strength should be performed before and at the end of the ageing cycles. Additional non-destructive tests are recommended, but are not compulsory for the standard. Moreover, Annex A of EN 16306 contains guidance on the limit values for the selection of marble types suitable for outdoor uses, especially façade applications. Eleven varieties of marble have been tested by means of this laboratory ageing test. Non-destructive tests such as the measurements of ultrasonic pulse velocity (UPV), adjacent grains analysis, open porosity, and water absorption have been executed together with the conventional flexural strength test. The results obtained from image analysis on thin sections indicate that the AGA index may not always be correlated with the other tests: amount of bowing, loss of flexural strength, or loss of UPV. Some consideration of the decrease in mechanical resistance and the bowing in relation to the variety of marble tested and the limit values indicated in Annex A of EN 16306 can be noted. It is known that bowing and rapid strength loss occur in some varieties of marble when used as exterior cladding and other exterior applications. Additional conclusions have been drawn: bowing and flexural strength correlate well and can be used to assess the suitability of the marble to be employed in outdoors.

  • 305.
    Benckert, A.
    Luleå tekniska universitet.
    Gruvdammar: Dammsäkerhet och efterbehandling2004In: Proceedings: NGM 2004. XIV Nordic Geotechnical Meeting, Linköping: Svenska geotekniska föreningen , 2004, p. G 51-Conference paper (Other academic)
  • 306.
    Bendz, David
    et al.
    Swedish Geotechnical Institute.
    Tiberg, Charlotta
    Swedish Geotechnical Institute.
    Berggren Kleja, Dan
    Swedish Geotechnical Institute.
    Toomväli, Cecilia
    Swedish Geotechnical Institute.
    Hågeryd, Ann-Christine
    Swedish Geotechnical Institute.
    Ndayikengurukiye, Godefroid
    Swedish Geotechnical Institute.
    Ohlsson, Yvonne
    Swedish Geotechnical Institute.
    Alwmark, Carl
    Kisaskans kemi2015In: Geologiskt forum, ISSN 1104-4721, Vol. 22, no 86, p. 14-15Article in journal (Other academic)
    Abstract [sv]

    I Sverige finns många hundratusentals ton kisaska på gamla industriområden där svavelsyratillverkning för pappersbruken ägt rum.

  • 307. Bengtsson, PE
    et al.
    Bergdahl, U
    Olsson, L
    Ouacha, M
    Petersson, E
    Statistiskt beräknade partialkoefficienter till Nybyggnadsregler för geokonstruktioner. Etapp 1 - en förstudie1993Report (Other academic)
  • 308. Bengtsson, PE
    et al.
    Johansson, L
    Development of methods for settlement calculations. Analysis of two test embankments using the CESAR-LCPC program1999Report (Other academic)
  • 309.
    Benhalima, Mehdi
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Evaluation of the differences in characterization and classification of the rock mass quality: A comparison between pre-investigation, engineering geological forecast and tunnel mapping in the Northern Link project and the Cityline project2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the construction of a tunnel, the characterization of the rock mass is performed in three different steps, in the pre-investigations, in the engineering geological forecast and in the tunnel mapping during construction. There has in previous work been observed that discrepancies exist between the results from these different steps, with a tendency to assign poorer rock mass quality in the tunnel mapping than in the pre-investigations and in the engineering geological forecast. One example is the work done by Kjellström [1] on the Cityline where the divergence in rock mass quality was analyzed between the different steps. If a divergence exists between the engineering geological forecast and the actual conditions observed in the tunnel mapping, it will influence both planning and budget. It is therefore important that the engineering geological forecast is as close as possible to the actual rock mass conditions in the field.

    The aim of this thesis was, using the case study of the Northern Link, to analyze those discrepancies in the rock mass quality estimated in the characterization and in the classification between the mapping of drill cores, the engineering geological forecast and the tunnel mapping thus complementing the work by Kjellström [1]. The aim was also identifying which parameters included in the Q-system that causes these discrepancies

    The analysis of the results showed that it is difficult to make the engineering geological forecast and the actual mapping match for every single meter, but that the overall correlation between them was good. The methodology used in the characterization and classification in the different phases (drill-core mapping, engineering geological forecast, tunnel mapping) may to some extent explain this divergence. The parameters Jr, Jn and Ja, included in the Q-system were the ones identified as having the largest influence on the discrepancies. In future work, it is recommended that focus is given on these parameters.

    A way to improve future engineering geological forecast for tunnel contracts would be to have a better follow up of the engineering geological forecast and to have standardized guidelines on how to assess clearly the value of the Q parameters in each phase (for the drill cores as well as for the actual mapping). The reduction of those differences would then lead to a better planning and budget management in future tunnel projects in Sweden.

  • 310. Bergau, W
    Measurements in grain silos during filling and emptying1959Report (Other academic)
  • 311. Bergdahl, K
    et al.
    Cederbom, C
    Göransson, G
    Prioritering av områden för skredriskanalys. Klimatanpassningsanslag 20132013Report (Other academic)
    Abstract [sv]

    För att skredriskkarteringarna ska ge så stor samhällsnytta som möjligt så har SGI studerat de tidigare identifierade vattendragsområden (Slutrapport: Nyttiggörande av material från Göta älvutredningen, SGI 2012) närmare och tagit fram en inbördes prioriteringsordning. Prioriteringen har gjorts i två steg: (I) statistisk analys av förutsättningar för skred, möjliga konsekvenser av skred samt förväntad klimatpåverkan med två olika metoder baserat på ett antal specificerade kriterier; (II) sammanvägning av resultatet från den statistiska analysen och andra samhällsaspekter som är viktiga i sammanhanget. Baserat på resultatet från den statistiska analysen så har områdena rangordnats från 1-12. Ångermanälven får högst rangordning sammanlagt. Därefter kommer områdena Säveån, Umeälven och Dalälven A med något varierande inbördes ordning. Beroende på osäkerheter och ojämnhet i data kan endast en relativ ordningsföljd ges, observera att samtliga områden bedöms viktiga att skredriskkartera ur ett samhällsperspektiv. Efter en sammanvägning med andra samhällsaspekter blir rekommendationen att Ångermanälven, Säveån och Norrströms utlopp är de mest angelägna att skredriskkartera före övriga vattendrag.

  • 312. Bergdahl, K
    et al.
    Odén, K
    Landslide risks in a changing climate - The Nors River valley. Part 1: Map report and summary of results2015Report (Other academic)
    Abstract [en]

    (1) Landslide risk analysis along the Nors River valley – in brief; (2) Landslide risks in Nors River valley; (3) Reducing landslide risk; Appendices: (1) Overview of map charts; (2) Probability maps; (3) Consequence maps; (4) Landslide risk maps

  • 313. Bergdahl, K
    et al.
    Odén, K
    Skredrisker i ett förändrat klimat - Norsälven. Del 1: Kartredovisning och sammanfattning av resultat2015Report (Other academic)
    Abstract [sv]

    (1) Skredriskanalys Norsälven - i korthet; (2) Skredrisker i Norsälvens dalgång; (3) Minskning av skredrisk; Kartbilagor: (1) Bladindelning; (2) Sannolikhetskartor; (3) Konsekvenskartor; (4) Skredriskkartor

  • 314. Bergdahl, K
    et al.
    Odén, K
    Löfroth, H
    Göransson, G
    Jönsson, Å
    Kiilsgaard, R
    Skredrisker i ett förändrat klimat - Norsälven. Del 2: Metod för kartläggning2015Report (Other academic)
    Abstract [sv]

    (1) Bakgrund; (2) Utredningens genomförande; (3) Klimat; (4) Geologi; (5) Geoteknik; (6) Yt- och grundvattenförhållanden; (7) Erosion; (8) Stabilitetsberäkningar; (9) Sannolikhetsanalys; (10) Konsekvensanalys; (11) Analys av skredrisker; (12) Åtgärdsbehov och klimatanpassning; Bilaga: (1) Inventerade geotekniska utredningar

  • 315.
    Bergdahl, Karin
    et al.
    Swedish Geotechnical Institute.
    Odén, Karin
    Swedish Geotechnical Institute.
    Löfroth, Hjördis
    Swedish Geotechnical Institute.
    Jönsson, Åsa
    Swedish Geotechnical Institute.
    Kiilsgaard, Ramona
    Swedish Geotechnical Institute.
    Landslide risks in a changing climate, Nors River pilot study area2016In: Proceedings of the 17th Nordic Geotechnical Meeting, NGM 2016, Reykjavik, Iceland, 25-28 May, 2016, Reykjavik: Icelandic Geotechnical Society , 2016, p. 1193-1202Conference paper (Refereed)
    Abstract [en]

    The Swedish Geotechnical Institute (SGI) is commissioned by the Swedish government to perform risk assessment for landslides within the national climate change adaptation allowance. Our commission includes mapping the risks in present and future climate conditions. Making use of material from the previously completed Göta River valley Investigation (GRI), SGI identified and prioritized Swedish watercourses for landslide risk mapping (Bergdahl et al in 2013). The Nors River valley was chosen as a pilot area for the development of a simplified methodology for landslide risk mapping. The investigation along the river is based on the methodology that was developed within the GRI. It aims to provide a sufficient basis for planners in municipalities and county administrative boards in their work with prioritization and preparation of adaptation measures. Methodological development has been carried out in order to reduce the costs of investigation and to simplify the interpretation of the maps, thereby increasing the societal relevance and usability of the results. The landslide risk analysis along the Nors River valley has resulted in a comprehensive overview of the risk of landslides in the present and future climate, for built-up as well as yet undeveloped land and areas with vital infrastructure. The methodology for risk mapping, that has been developed, is applicable for landslide risk mapping along other streams and river valleys. The resulting maps are made available in a free GIS Webb application, accustomed to the users of the information.

  • 316. Bergdahl, U
    et al.
    Eriksson, U
    Bestämning av jordegenskaper med sondering - en litteraturstudie1983Report (Other academic)
  • 317. Bergdahl, U
    et al.
    Fogelström, R
    Larsson, KG
    Liljekvist, P
    Förebyggande av sättningar i ledningsgravar - en förstudie1979Report (Other academic)
  • 318. Bergdahl, U
    et al.
    Hult, G
    Ottosson, E
    Belastningsförsök på plattor grundlagda i friktionsjord för bestämning av jords deformationsegenskaper. Försök vid Albysjön, Fittja1986Report (Other academic)
  • 319. Bergdahl, U
    et al.
    Hult, G
    Ottosson, E
    Belastningsförsök på plattor grundlagda i friktionsjord för bestämning av jords deformationsegenskaper. Försök vid SGI:s provfält - Kolbyttemon, Linköping1984Report (Other academic)
  • 320. Bergdahl, U
    et al.
    Hult, G
    Ottosson, E
    Spread footings in sands. Calculation of bearing capacity and settlements1986Report (Other academic)
  • 321. Bergdahl, U
    et al.
    Lindahl, A
    Ouacha, M
    Bro över Öre älv vid Skarda, Väg 353 Bjurholm – Lycksele. Sättningsuppföljning av bro2007Report (Other academic)
    Abstract [sv]

    (1) Bakgrund och syfte; (2) Geotekniska undersökningar; (3) Geologiska och geotekniska förhållanden; (4) Beskrivning av bro; (5) Uppföljningar; (6) Nya beräkningar; (7) Jämförelse av sättningsförlopp; Bilagor: (A) CPTU-sonderingen, Borrhål, 1, Västra stödet; (B) CPTU-sondering, Borrhål 4, Östra stödet; (C) Resultat av laboratorieundersökningar

  • 322. Bergdahl, U
    et al.
    Möller, B
    Utveckling av hejarsonderingsmaskin. Hejarsond för jordparameterbestämning. Resultat av ett utvecklingsprojekt1980Report (Other academic)
  • 323. Bergdahl, U
    et al.
    Olsson, C
    Ouacha, M
    Kontrollberäkning av Eurocodes. Grundläggning /ENV 1991-1 Basis of Design; ENV 1997-1-1, General rules for geotechnical design/1996Report (Other academic)
    Abstract [sv]

    (1) Beräkningsförutsättningar; (2) Sammanfattning av beräkningsresultat; (3) Beskrivning av exemplet; (4) Exempel: Grundläggning på friktionsjord; (5) Grundläggning på berg

  • 324. Bergdahl, U
    et al.
    Sällfors, G
    Geotekniska undersökningar i fält1984Report (Other academic)
    Abstract [sv]

    (1) Sonderingsmetoder; (2) Provtagningsmetoder; (3) In situ-provning; (4) Grundvattenmätningar; (5) Redovisning av fältundersökningsresultat; (6) Metoder för kontroll och uppföljning; Bilagor: Svenska Geotekniska Föreningens beteckningsblad

  • 325. Bergdahl, U
    et al.
    Tränk, R
    Korrosionsskyddande beläggningar på stålpålar i jord - Provning och reptålighet2005Report (Other academic)
    Abstract [sv]

    (1) Program för undersökningarna; (2) Genomförande av försöken; (3) Resultat av undersökningarna; (4) Analys av resultaten; Bilagor: (1) Påltyper, dimensioner, stålkvalitet och beläggningskvalitet; (2) Fält- och laboratorieundersökningar. Provplats Universitetsområdet, Linköping; (3) Skikttjockleksmätningar och skadebedömning före pålslagning samt efter pålslagning och uppdragning; (4) Pålslagningsprotokoll; (5) Skikttjockleksmätningar m m efter uppdragning av pålar; (6) Jämförelser mellan skikttjocklekar före och efter pålslagning; (7) Noterade skador på pålar efter uppdragning

  • 326. Bergenståhl, L
    Temperaturens inverkan på leras egenskaper. Resultat av triaxialförsök vid olika temperaturer1993Report (Other academic)
  • 327. Bergenståhl, L
    et al.
    Lehtmets, M
    Sundberg, J
    Försöksfält för högtemperaturlagring i lera. Förprojektering1990Report (Other academic)
  • 328. Bergenståhl, L
    et al.
    Magnusson, C
    Rydell, B
    Dahlöf, P
    Värmepumpanläggning med värmelager i lera för skola och sporthall i Söderköping. Mätning och utvärdering. Delrapport 1 1987-19891990Report (Other academic)
  • 329. Berggren, B
    et al.
    Bengtsson, PE
    Anvisningar för dimensionering, utförande och kontroll av prylprintar1986Report (Other academic)
  • 330. Berggren, B
    et al.
    Fallsvik, J
    Riskvärdering av slänters stabilitetsförhållanden1991Report (Other academic)
  • 331. Berggren, B
    et al.
    Fallsvik, J
    Stability of slopes in clay. A description of a risk evaluation method1991Report (Other academic)
  • 332. Berggren, B
    et al.
    Fallsvik, J
    Hintze, S
    Stille, H
    Lerslänters stabilitetsförhållanden. Riskvärdering och beslutsteori. Förslag till metod för riskvärdering1991Report (Other academic)
    Abstract [en]

    Stability conditions in clay slopes. Risk assessment and decision theory. Risk assessment method - proposal

  • 333.
    Berggren, Christian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Dig or no dig?: En jämförelse mellan schaktfria tekniker och konventionell schakt vid VA-produktion.2015Independent thesis Basic level (university diploma), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Sweden's public water and sewer system consists of 191 000 km of water- and sewer pipelines. Annually is it about 380 km of pipelines which not is reconditioned even if it should if the renovation rate should keep up with the ageing of the pipelines. The renovation costs large sums of money which is supposed to be one of the biggest reasons that some of the renovations are absent. In order to keep production going in Sweden’s water and sewer - sector is it required that both finance and time is to be reviewed.

    This study compares the economics of various methods of producing water and sewer lines. The work also includes a study of pollution in form of carbon dioxide during the production of pipelines. The methods that have been raised are conventional excavation, directional drilling and relining. In directional drilling has two methods been examined, JT and AT drilling. For relining the examined methods are slip-lining and closed -fit.

    The work has been done for Skanska Väg och Anläggning Väst , which is part of Skanska Sverige AB. The comparison has been performed with a literature study to complete the theory behind the background. The result in the comparative study of economics and environment is based on calculations from completed and ongoing projects within Skanska, as well as interviews with various contractors.

    The results show that trenchless technologies emit less carbon dioxide than conventional excavation which is not surprising since the excavation handled much larger land masses. In regards to the economy can be said that the basis of the result is substandard but a fact is still that what is most effective due to cost varies depending on the project. A generalization can be made for trenchless methods. These tend to be more profitable, the deeper and longer works, and the fewer connections and the ramifications it is on line. Directional drilling is limited by the drilling mud that is an out coming waste during the production. For bigger line sizes will the disposing of the sludge be a major expense which in some cases can make it unprofitable to drill. Generally drilling bigger sizes with god profit demands objects worthy of protection above ground.

  • 334. Berggren Kleja, D
    et al.
    Ohlsson, Y
    Kunskapsläge och förutsättningar för återvinning av metaller i förorenade massor2013Report (Other academic)
    Abstract [sv]

    För områden som är förorenade med höga metallkoncentrationer kan återvinning av metallerna potentiellt vara ett mer miljömässigt hållbart alternativ än att flytta de förorenade massorna till en deponi. Idén att återvinna metaller från förorenade områden anses god och har stor acceptans i ett internationellt perspektiv. I riktlinjer som utgivits av amerikanska Environmental Protection Agency, EPA, anges återvinning av metaller exempelvis som ett förstahandsval i fall då det är möjligt. Samtidigt finns det en rad hinder av såväl ekonomisk som teknisk natur. Vårt syfte med denna kunskapssammanställning är att: (1) Översiktligt inventera genomförda projekt nationellt och internationellt; (2) Sammanställa och utvärdera befintliga tekniker när det gäller återvinning av metaller från förorenad mark; (3) Inventera möjligheter och hinder att i framtiden återvinna metaller från förorenade jord i större omfattning.

  • 335.
    Berglin, Alexander
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Short-term deformations in clay under a formwork during the construction of a bridge: A design study2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    During the casting of a concrete bridge deck, the temporary formwork is causing the underlying ground to deform if a shallow foundation solution is used. There are often demands on the maximum deformation of the superstructure when designing the foundation for the formwork.  To keep the deformations within the desired limits, several ground improvement methods like deep mixing columns or deep foundation methods like piling can be used. Permanent ground improvement methods are however expensive, and far from always needed. To reduce the need for unnecessary ground improvements, it is crucial to calculate the predicted deformations accurately during the design phase.

    The purpose of this thesis was to investigate how short-term deformations in clay under a formwork during bridge construction should be calculated more generally in future projects.

    Three different calculation models have here been used to calculate the ground deformations caused by the temporary formwork. A simple analytical calculation and two numerical calculations based on the Mohr Coulomb and Hardening Soil-Small constitutive models. The three calculation models were chosen based on their complexity. The analytical calculation model was the most idealised and the Hardening Soil-Small to be the most complex and most realistic model.

    Results show that the numerical calculation model Mohr Coulomb and the analytical calculation model gives the best results compared to the measured deformation. One of the most probable reasons for the result is that both of the models require a few input parameters that can easily be determined by well-known methods, such as triaxial-, routine- and CRS-tests. The more advanced Hardening soil small model requires many parameters to fully describe the behaviour of soil. Many of the parameters are hard to determine or seldom measured. Due to the larger uncertainties in the parameter selection compared with the other two models, the calculated deformation also contains larger uncertainties. 

  • 336.
    Bergliv, Elin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Edeskär, Tommy
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Laboratory study on two-dimensional image analysis as a tool to evaluate degradation of granular fill materials2016In: Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM: Reykjavik, Iceland 25th – 28th of May 2016, 2016, p. 461-470Conference paper (Refereed)
    Abstract [en]

    The shape of granular materials is known to affect strength and stiffness properties of soil and fills. Settlements in coarse fills are often explained by rearrangement within the soil skeleton induced by crushing and rounding of the individual aggregates in the intergranular contact points. These processes are not well investigated since it is difficult to measure changes at an aggregatelevel.Currently few attempts have been made to effectively measure and classify shape of granular soil and fill materials. One of the more promising methodologies is digital image analysis. Even if there are some studies on both two and three dimensional analyses on shape of aggregates, no study has focused on identifying shape changes as function of degradation effects of the fill materials.In this study degradation of ballast material has been studied in standardized micro Deval and Los Angeles tests and analysed by two dimensional image analysis and statistical methods. The results showed it was possible to statistically separate the shape and size of the materials before and after the degradation tests. To identify this difference it is essential to use more than one variable each for size and shape.The conclusion of the study is that two-dimensional image analysis can be used as a tool to measure and quantify shape changes on an aggregate level in order to measure degradation. If further developed, the technique can be useful to study deformation processes, e.g. crushing and rounding of aggregates, in coarse fill materials.

  • 337.
    Berglund, Andreas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Prognos av vägars bärförmåga vid tjällossningen: Användning av "Minnesotamodellen" på en teststräcka i Sverige2010Report (Other academic)
    Abstract [en]

    The global trend towards a warmer climate and temperatures near or just above 0 °C during winter months, will most likely be more common in future. One of the consequences of this climate change could, in a worst-case scenario, be freezing and thawing over a significant part of the winter with corresponding road bearing capacity problems. Bearing capacity problems may lead to increased costs to society when heavy traffic is forced to change route or carry less weight. In addition, road maintenance costs will increase. According to pulp industry calculations, this industry sector will face additional costs in the range of 510-590 Million SEK every year due to road bearing capacity problems. In addition to this, the costs related to the rapidly growing bio fuel industry will be added. If a reliable forecast of load-bearing capacity problems and potential load restrictions on roads can be found, it would be cost effective for road administration and society. This research report is a part of a work to find methods to forecast bearing capacity problems on roads. The report gives an idea of the possibility to use the temperature based model used in Minnesota, USA in Sweden. The evaluation is done by comparing falling weight deflectometer (FWD) test results with the results from the temperature based forecast model. Temperatures and FWD data were collected in 1997 on a road approximately 7 km outside Luleå, Sweden. The road structure was from the surface: 0,10 m asphalt, 0,40 m sandy gravel/gravely clayey sand and 3,0 m silty clay overlaying a silty moraine. In the report the FWD concept, as well as the FWD parameters of importance are described. How the temperature data was collected is described. The temperatures were collected at a depth of 0,20 m and 0,12 m below the asphalt layer respectively. FWD data was normalised to a force of 50kN. The radius of the segmented falling plate was 0,12 m and all calculations were carried out in accordance with Swedish guidelines. Based upon the FWD tests, the following parameters were evaluated: i/load carrying index, ii/surface modulus, iii/subgrade modulus and iv/"AREA-parameter". A daily average air temperature was determined based upon the detailed measured temperatures. A comparison was done with an average value calculated solely on the recorded maximum and minimum temperatures. It is shown that the two methods gave similar results when used in the forecast model. A short description of the temperature based forecast model is presented as well as an example of how to use it. The needed reference temperature was in the field test evaluated to -0,65 °C and the thaw-degree day limit before the road starts to thaw was determined to 22,2 °C-days. The evaluated FWD parameters show bearing capacity loss at slightly different days. Load carrying index shows a loss of bearing capacity after March 14. As expected the surface modulus is strongly influenced by the air temperature and shows low values on March 10, April 1. After April 11 it decreases significantly. The subgrade modulus shows less stiffness after March 26 and is not as affected by changing air temperatures as the surface modulus. The AREA parameter is also affected by the oscillations in air temperature, much like the surface modulus. It shows low values on March 10 and April 1. After April 11 it decreases significantly towards the lowest values registered in the study. The temperature based forecast model shows that the limit for the accumulated thaw index is reached on March 10 and on April 22-23. The results from the forecast model based upon the daily average temperatures and based upon daily maximum and minimum temperatures only, shows almost the same dates for bearing capacity reductions. Thus, the more simple method with maximum and minimum temperature values seems to give enough accuracy. When comparing the FWD results: AREA-parameter and subgrade modulus with results from the Minnesota model, the subgrade modulus seems to have the greatest agreement with the forecast model. However, they both seem to show the overall development of low bearing capacity during thaw. The overall conclusion about the temperature based forecast model is that it seems to give fairly good results and work well. It will work better if it can be further calibrated but it has some flaws if the temperature seesaws around 0 °C. The forecast model should, despite this, be able to assist road holders in Sweden as a planning tool, when dealing with bearing capacity problems during thaw.

  • 338.
    Berglund, Andreas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Prognos av vägars bärförmåga vid tjällossningen: användning av temperatur som nyckeltal2010Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The global trend towards a warmer climate and temperatures near or just above 0 °C during winter months, will most likely be more common in future. One of the consequences of this climate change could, in a worst-case scenario, be freezing and thawing over a significant part of the winter with corresponding road bearing capacity problems. Bearing capacity problems may lead to increased costs to society when heavy traffic is forced to change route or carry less weight. In addition, road maintenance costs will increase. According to pulp industry calculations, this industry sector will face additional costs in the range of 510-590 Million SEK every year due to road bearing capacity problems. In addition to this, the costs related to the rapidly growing bio fuel industry will be added. If a reliable forecast of load-bearing capacity problems and potential load restrictions on roads can be found, it would be cost effective for road administration and society. This text presents the content of the licentiate work is presented and in what report more information could be found. One aspect of frost damage on roads that is highlighted in the thesis is decision making when conducting a road inventory. In a study conducted within the licentiate work it was shown that the results from different actors performing frost inventory on the same road stretch can vary a lot. There should be efforts made to reduce the individual dependence when performing a road inventory. The main part of the licentiate work deals with a model for the prediction of bearing capacity problems on roads. The work gives an idea of the possibility to use the temperature based model used in Minnesota, USA in Sweden. The evaluation is done by comparing falling weight deflectometer (FWD) test results with the results from the temperature based forecast model. When comparing the FWD results: AREA-parameter and subgrade modulus with results from the Minnesota model, the subgrade modulus seems to have the greatest agreement with the forecast model. However, they both seem to show the overall development of low bearing capacity during thaw. The overall conclusion about the temperature based forecast model is that it seems to give fairly good results and work well. It will work better if it can be further calibrated but it has some flaws if the temperature seesaws around 0 °C. The forecast model should, despite this, be able to assist road holders in Sweden as a planning tool, when dealing with bearing capacity problems during thaw.

  • 339.
    Berglund, Andreas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Studie av modell för prognos av vägars bärförmåga vid tjällossningen: "Minnesotamodellen"2010Report (Other academic)
    Abstract [en]

    Many roads are affected negatively by thaw with loss of bearing capacity as a consequence. Sometime load restriction policies must be applied on these roads. To be able to communicate potential bearing capacity problems in time with the road users, a prognosis model is needed. Such a model is described in this report. The model is described based upon a report made at Washington state department of transportation, WSDOT. WSDOT had carried out thermal analysis by FEM on four different road sections. The four sections are presented and the thermal properties of the road materials are given. A most likely misprint in the original report is commented upon and a table with correct SI-units is presented. The results coming from the thermal analysis is presented. Thawing in the tested road sections starts when the daily average air temperature is -1,7 °C to -1,1 °C. Limits for a should and a must level of accumulated thawing index is presented as 25 °F-days and 50 °F-days. When the level is reached load restrictions should apply. In the Minnesota Department of Transportation, Mn/DOT, version of the forecast model only one limit is used. The length of the load restrictions are based on the complete thaw of the road construction. Two equations for calculating the length of restrictions based on FI and TI are presented. Comparisons between the results of the forecast model and frost depth meters have been carried out and showed acceptable results. The forecast model is working better when fine grained materials is present than with coarse grained materials. The model was stated usable but in need of in-situ calibration. The model has been altered in the Mn/DOT version by letting the reference temperature vary during spring. This is said to be a way of taking the increasing intensity of the net heat flux and angle of the sun into consideration. It can also be seen as an easy way of calibrating the forecast model. The three day weather forecast is used to determine when the limit value for accumulated thaw index is reached. This gives the forecast model a three days forecast on bearing capacity problems. Within Mn/DOT maximum 8 weeks duration for load restrictions are used. Research showing that load restrictions are not socioeconomic defendable and that it is more economic to have the road repaired when it gets damaged is presented. Other works say that there is a value in load restrictions. Socioeconomic calculations may contain assumptions and whether or not they are correct is not discussed in this report. Before the forecast model could be implemented in Sweden there is a need for testing. Air and ground temperature data needs to be collected and analysed according to this report. The temperature data will give reference temperature and limit value to use when evaluating thaw index. The test results from the forecast model should be compared with for example falling weight deflection data from the same location to answer the question whether the agreement is good or not. The forecast model is straight forward and simple. Some questions about reliability need future testing before a recommendation whether or not it is suitable to be used in Sweden.

  • 340.
    Berglund, Andreas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Tjäle - en litteraturstudie med särskilt fokus på tjällossning2009Report (Other academic)
    Abstract [sv]

    Denna forskningsrapport är en litteraturgenomgång av en del av allt som finns skrivet om tjälprocessen och de problem tjälen skapar. Rapportens övergripande fokus ligger till en början på att ge en överblick över tjälprocessen och presentera grunderna i denna. Efter hand glider fokus över mot tjällossningen och de problem som förknippas med tjällossning. En allmän presentation av frusen jord, jord med en temperatur under 0°C, och en överblick över tjälforskningens historia från år 1765 och Beskow till mer nutida forskningsrön presenteras allra först i rapporten. Jordens termiska egenskaper är essentiell för tjälprocessen och beskrivs med hjälp av begrepp såsom termisk konduktivitet (värmeledningstalet λ), värmekapacitet (c), termisk diffusivitet (α) och latent värme (L). Temperaturprofilen beskrivs i termer av geotermisk gradient, whiplashkurva och aktivt område. Med aktivt område menas det område som tinar respektive fryser i permafrost och säsongstjäle.Tjälnedträngningen som orsakas av negativa varaktiga temperaturer vid markytan beskrivs i rapporten. Negativa yttemperaturer skapar ett värmeflöde från marken. Marken kyls ned i och med värmeavgången och bildandet av islinser i jorden inleds. Vattentransporten till tjälfronten som påverkar bildandet av islinser är komplex och fenomenet är än inte helt utrett. De två huvudspåren kapillärt sug och att vattentransporten beror av fysisk-kemiska egenskaper hos jorden presenteras. Vattentransporten till islinsen sker via en vattenfilm av ofruset vatten, den ofrusna vattenkvoten betecknas wu. Den hydrauliska konduktiviteten minskar med negativa temperaturer på grund av att vattentransporten sker i den ofrusna delen av vattnet, och wu minskar med negativa temperaturer. Beräkning av tjäldjup presenteras genom en härledning av Stefans formel, en presentation av Stefans modifierade formel och en förklaring av köldmängdsbegreppet. Modifierad Stefans formel som tar hänsyn till jordens värmekapacitet presenteras också. Förutom lufttemperaturen bestäms tjäldjupet i en jordprofil främst av jordmaterialets värmetekniska egenskaper. Tjällyftning och bestämning av tjällyftets storlek med segregation potential theory behandlas. Fenomenet vid tjällossning beskrivs samt problemen vid tjällossningen presenteras. För bärighetsproblem vid tjällossningen är dräneringen av vägkonstruktionen kritisk eftersom de ökade portrycken innebär minskade effektivspänningar och minskad skjuvhållfasthet. Dräneringsförmågan inverkar främst om urtjälningshastigheten är hög, mycket is övergår till vatten på kort tid. Sättningar på grund av tjällossning styrs främst av mängden is i jorden. Tjälfarlighetsklassificeringssystemen använda i Sverige, Norge, Finland och USA beskrivs och en jämförelse mellan dessa görs. Två jordar klassificeras utifrån kornfördelningskurvorna, för en grusig sand ger ländernas system samma svar, ej tjälfarlig. Även för den andra jorden, en sandig siltig lermorän klassificeras jorden som tjälfarlig, dock i olika grad. Hur vägar påverkas av tjälnedtränging (höjd hållfasthet, lägre hydraulisk konduktivitet), tjällyftning och tjällossning (bärighetsminskning, tjälskott med mera) beskrivs. Vägverkets system för väderdata VViS presenteras. Med hjälp av väderdata kan modeller för införandet av lastrestriktioner skapas. CTI-fordon har fördelar vid bärighetsnedsättningar. Sverige använder enbart visuella observationer vid införandet av lastrestriktioner på grund av bärighetsnedsättningar vid tjällossning. Flera andra länder och stater i USA använder mer sofistikerade metoder. I Minnesota används väderdata i form av frys- (FI) och töindex (TI) tillsammans med en referenstemperatur för att förutse när lastrestriktioner bör införas. Kanske är "Minnesotamodellen" något för Sverige.

  • 341.
    Berglund, Andreas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Tjälinventeringsprojektet: en jämförande studie av tjälinventeringar gjorda av olika aktörer2010Report (Other academic)
    Abstract [en]

    Roads are affected by frost. For maintenance and action planning of these roads, a well performed inventory is a necessary base. It will also be a base for priority of different objects for repair and maintenance. Therefore, it is very important to have a similar ground for the judgment. This can be difficult to achieve as different companies and persons are enrolled different years due to type of contract used, capacity, experience, knowledge etc. In a pre-study great differences were found when comparing two inventories done on the same road in year 2008 and 2009. The question was then raised, if the provided information on how to perform an inventory was good enough in order to carry out a high quality work. Another question raised, was if the differences really are that obvious between different persons performing the inventory.The method used for the study was to have four actors to carry out an inventory each on the same road, at the same time, and then compare the obtained results. The actors were "Konsult A" and B, Swedish Transport Association (TV) and persons from Luleå University of Technology (LTU). Ranked in order of practical experience the most experienced was Konsult B, then Konsult A, TV and LTU. The road studied was AC805 Lidbacken to Femvägaskälet. It is situated outside Skellefteå in the county of Västerbotten in the north part of Sweden. The total length of the studied road was about 15 km and it has an ADT of 576. Four sections, which represented the road as a whole and also showed the main differences and similarities, were closer analyzed. One section focused on an overview, one on cracks and two sections focused on bumps and roughness. In the report, the results from the four inventories are presented graphically in order to give the reader an overview and a chance to comparison. The results show that there are both great differences and similarities between the four inventories. The two most experienced, Konsult A and Konsult B had about the same percentage of their total crack length in class 2 (66 respectively 60%) and class 3 (~30%). The total amount of inventoried crack length differs however. Konsult A have in total 7355m and Konsult B 9157m, which means that Konsult A only reports approximately 80% of the length reported by Konsult B. TV had 18% class 2 and 82% class 3 cracks with a total length of cracks being 3246m, while LTU had 38% class 2 and 24% class 3 cracks. In this case the total crack length was reported to be 11029m. This means, that the total length of reported cracks varies between 3246 m to 11029 m, corresponding to approx. 21% and 74% of the total road length.The most experienced (Konsult B) and the least experienced performer (LTU) show most similarities in the overall road condition assessment and placement of damages. It is mentally exhausting to perform a road inventory by hand without small amount of technical support. It is shown in the report that the resolution seems to decrease after some time of work. As a consequence, many cracks in class 1 are registered in the beginning of the studied road stretch, while in the end cracks are more registered as long single cracks. After some time of work more cracks are registered as coherent cracks while they in fact are single cracks. It should therefore be considered if technical supporting systems, like e.g. GPS and computers with well developed software, should be more used in order to increase efficiency and quality of the final work. This should also reduce the impact of subjective decisions.One observation done in the study is that different persons might have different views of the purpose of the road inventory. One view is to perform just a road inventory, without any specific purpose, more than to get a view of the quality of the road. Another point of view is to do an inventory with the focus of what type of actions are to be carried out in future in mind. Depending on the focus, the results seem to differ. In this study, it seems like LTU, Konsult A and Konsult B have performed the inventory in the first way, while TV seems to have carried the inventory out with future actions in mind. This conclusion is based upon the observation that TV did not note any damages in class 1 throughout the whole road stretch, while the other did. By analysing the inventory results, it was found that errors in the distance measurements were present. It is therefore proposed that the customer should consider GPS-length measurements to eliminate this source of error. Inventory done with the base of digital photos will minimize some of the length measurement problems if the photos are taken by a camera connected to a GPS. However, inventory done by using digital photos only have several disadvantages in comparison with ordinary field inventory. The major drawback of this methodology is the difficulty to discover small damages and roughness. It is difficult to classify roughness. The roughness effect on driving experience is very much dependent on the speed of the inventory vehicle. Based on this study the speed of the inventory vehicle needs to be considered when doing a roughness inventory. Roughness inventory should be done at the roads intended speed to ensure that the roughness impact on driving comfort is correctly experienced and registered. One way to enhance the quality of road inventory could be to develop a clear and easy to understand description of method. It should be emphasised that experience is a key component when doing road a inventory, but an increased use of technical support systems can reduce the scatter in the assessment.

  • 342.
    Berglund, Andreas
    et al.
    LTU.
    Edeskär, Tommy
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Knutsson, Sven
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Mining and Geotechnical Engineering.
    Comparison between temperature based thaw weakening prediction model and field observation methods2011In: Proceedings of the 21st International Conference on Port and Ocean Engineering under Arctic Conditions, Montreal, 2011Conference paper (Refereed)
    Abstract [en]

    Structures like roads and port yards located in cold climate are affected by freezing and thawing every year. The global trend of a warmer climate and temperatures around 0°C for longer periods of time will change the freezing/thawing behaviour in many locations. The tendency will changeto have several freezing /thawing cycles in a given location every year. The bearing capacity of low volume roads and simple port yards will be affected by a prolonged thawing period with lower bearing capacity as a consequence. Bearing capacity problems can lead to increased costs for traffic as well as increased maintenance costs. Due to very high costs for destroyed structuresduring thaw, a lot can be gained if bearing capacity problems at a given site can be forecasted well in advance in order not to destroy the structure. Such a method should preferably be based upon simple measurements like air temperatures to make it easy to use also in remote areas. In the described temperature based model air and ground temperatures are used to develop anaccumulated thaw index and corresponding limits. When the thaw index limit is reached, the construction at the evaluated depth thaws, leading to increased pore water pressure and reduction of strength and bearing capacity. This paper presents a study of the application of the model at low volume roads in Sweden. Bearing capacity at the road was evaluated from field tests by falling weight deflectometer (FWD) test carried out 24 times during the thawing season i.e.March 4 through June 9. Predictions made by the model were compared with the subgrade module evaluated from the FWD series. The results show that the model might be possible to use in Sweden and elsewhere if minor adjustments are carried out.

  • 343.
    Bergman, Niclas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Aspects of probabalistic serviceability limit state design of dry deep mixing2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    An expanding population and increased need for infrastructure increasingly necessitate construction on surfaces with poor soil conditions. To facilitate the construction of buildings, roads and railroads in areas with poor soil conditions, these areas are often improved by means of foundation engineering. Constructions that are fairly limited in scope are often founded on shallow or deep foundations. However, these methods are relatively expensive and thus not applicable for large-scale constructions like roads and railroads. A cost-effective way to deal with poor soil conditions is to use ground improvement. This thesis deals with a ground improvement method called deep mixing (DD)using lime-cement columns.

    Lime-cement columns are manufactured by pushing a mechanical mixing tool to the desired depth, with the tool then rotated and retracted while a lime-cement binder is distributed into soil, forming lime-cement columns. Because of the complex mixing process and inherent soil variability, soil improved by DD shows high variability with respect to strength and deformation properties. Due to this high variability, it is difficult to predict the properties in advance; it is therefore important to verify the properties after installation. In Sweden, this is normally done using the column penetration test (KKK) method.

    Current design praxis considers evaluated mean values in the design, and the effect of variability and uncertainties is dealt with by using a sufficiently high total factor of safety. A more rational approach for dealing with the effect of variability and uncertainties on the reliability of a mechanical system is to include them as parameters in the design model. This can be done by using reliability-based design (RRR). A major incentive for using 𝑅𝑅𝑅 is that lower variability in design properties produces higher design values. This is important since it encourages contractors to improve their manufacturing methodologies because 𝑅𝑅𝑅 allows more homogenous columns to be assigned higher design values. Reliability-based design is also in line with Eurocode 7, which states that the selection of the characteristic values for geotechnical parameters shall take the variability of the measured property values into account.

    The first part of this doctoral thesis deals with test methods and quantification of the strength variability of soil improved by lime-cement columns. Tip resistances from three different test sites using three different penetration test methods – the cone penetration test, the column penetration test and the total-sounding test – are analysed and quantified in terms of means, variances and scale of fluctuations. The second part introduces RRR in serviceability limit state (SSS) design, using First Order Reliability Methods (FFFF) and Monte-Carlo simulations.

    Summarizing the most important findings and conclusions from this study:

    •  The scale of fluctuation was estimated to be 0.2-0.7 m and 0-3 m in the vertical and horizontal direction, respectively.
    •  The relation between cone tip resistances measured using the cone penetration test and column penetration test does not correspond to the cone factors proposed in previous studies and in the Swedish Design Guidelines.
    •  The agreement between the column penetration test and total-sounding test was found to be “good enough”. It is therefore suggested that the total-sounding test be used as a complement to the column penetration test in evaluating the average strength properties of a group of medium- and high-strength lime-cement columns.
    • Reliability-based design is a rational approach to incorporate strength and deformation parameter variability with an SSS design.
  • 344.
    Bergman, Niclas
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Characterization of strenght vaiability for reliability-based design of lime-cement columns2012Licentiate thesis, comprehensive summary (Other academic)
  • 345.
    Bergman, Niclas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Al-Naqshabandy, Mohammed Salim
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Variability of strength and deformation properties in lime-cement columns evaluated from CPT and KPS measurements2013In: Georisk: Assessment and Management of Risk for Engineered Systems and Geohazards, ISSN 1749-9518, E-ISSN 1749-9526, Vol. 7, no 1, p. 21-36Article in journal (Refereed)
    Abstract [en]

    The strength variability of soil improved by deep mixing with lime-cement columns is generally high. Eurocode 7 states that selection of characteristic values for geotechnical parameters shall take the variability of measured property values into account. This variability can be considered in the design by using reliability-based design. With reliability-based design, three statistical parameters are needed to evaluate the design value; mean, variance and scale of fluctuation. In this paper, the shear strength of soil improved by lime-cement columns was evaluated using two different penetration methods, the cone penetration test and the column penetration test. The strength was quantified statistically by the mean, variance and scale of fluctuation, while each test method was analyzed and discussed with a focus on its influence on the design value. Based on the analyses, the column penetration test is suggested as a test method for soil improved by lime-cement columns.

  • 346.
    Bergman, Niclas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Ignat, Razvan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics. Skanska Sverige AB.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Serviceability Limit State design of lime-cement columns - A reliability-based design approach2014In: Geotechnical Safety and Risk IV - Proceedings of the 4th International Symposium on Geotechnical Safety and Risk, ISGSR 2013 / [ed] D . Q . Li, London: Taylor & Francis Group, 2014, p. 417-422Conference paper (Refereed)
    Abstract [en]

    Deep mixing with lime-cement columns is a ground improvement method used to improve the strength and deformation properties of soft cohesive soils. Due to the complex manufacturing process, the variability in the strength and deformation properties is normally high. A rational approach to include variability in the design process is by introducing Reliability-Based Design (RBD). This paper presents a reliability-based design approach for Serviceability Limit State (SLS) design of soil improved by lime-cement columns using the First-Order Reliability Method (FORM). The paper further presents the impact of uncertainties, reliability indices and area replacement ratios on the relationship between the characteristic value and the design value with respect to the column modulus of elasticity.

  • 347.
    Bergman, Niclas
    et al.
    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.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Probabilistic serviceability limit statedesign approach for dry deep mixingManuscript (preprint) (Other academic)
  • 348.
    Bergman, Niclas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Alternativ metod för verifiering av hållfasthet hos kalkcementpelare2013In: Bygg & teknik, ISSN 0281-658X, no 1, p. 75-79Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Inom ett doktorandprojekt på Kungliga Tekniska högskolan (KTH) har möjligheten till att använda Jb-totalsondering som testmetod för verifiering av hållfasthet hos kalkcementpelare studerats. Syftet med doktorandprojektet, som är finansierat av Svenska Byggbranschens Utvecklingsfond (SBUF) och Trafikverket, är att öka förståelsen för variationer i hållfasthets- och deformationsegenskaper hos kalkcementpelare och att undersöka variationernas betydelse vid sannolikhetsbaserad dimensionering i bruksstadiet, Bergman (2012).

  • 349.
    Bergman, Niclas
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Comparing column penetration and total–sounding data for lime–cement columns2014In: Ground Improvement, ISSN 1365-781X, E-ISSN 1751-7621, Vol. 167, no 4, p. 249-259Article in journal (Refereed)
    Abstract [en]

    In Sweden, the method commonly used for the quality control of lime–cement columns is the column penetration test. However, it is recommended for depths of no more than 8 m because the probe easily deviates from the column at greater depths. As an alternative to facilitate keeping the probe vertical, a centre hole is normally bored in the column using the total-sounding test method. The aim of this paper is to quantify the agreement between the two methods. If there is good agreement, it should be possible to use the less expensive and less time-consuming total-sounding test as a complement to the column penetration test. The analyses suggest good agreement between the methods, and it is therefore suggested that the total-sounding test be used as a complement to the column penetration test in evaluating the average strength properties of a group of medium- and high-strength lime–cement columns.

  • 350. Bergman, R
    et al.
    Andersson-Sköld, Y
    Fallsvik, J
    Hultén, C
    Elliot, AL
    Measures for climate change in Sweden. Altered rainfall and sea levels2011Report (Other academic)
    Abstract [en]

    (1) Planning and monitoring; (2) Resistance; (3) Resilience; (4) Domestic measures

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  • text
  • asciidoc
  • rtf