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  • 1351.
    Wersäll, Carl
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Frequency Optimization of Vibratory Rollers and Plates for Compaction of Granular Soil2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Vibratory rollers are commonly used for compaction of embankments and landfills. This task is time consuming and constitutes a significant part of most large construction and infrastructure projects. By improving the compaction efficiency, the construction industry would reduce costs and environmental impact.

    This research project studies the influence of the vibration frequency of the drum, which is normally a fixed roller property, and whether resonance can be utilized to improve the compaction efficiency. The influence of frequency on roller compaction has not before been studied but the concept of resonance compaction has previously been applied successfully in deep compaction of fills and natural deposits.

    In order to examine the influence of vibration frequency on the compaction of granular soil, small-scale compaction tests of sand were conducted under varying conditions with a vertically oscillating plate. Subsequently, full-scale tests were conducted using a vibratory soil compaction roller and a test bed of crushed gravel. The results showed that resonance can be utilized in soil compaction by vibratory rollers and plates and that the optimum compaction frequency from an energy perspective is at, or slightly above, the coupled compactor-soil resonant frequency. Since rollers operate far above resonance, the compaction frequency can be significantly reduced, resulting in a considerable reduction in fuel consumption, environmental impact and machine wear.

    The thesis also presents an iterative equivalent-linear method to calculate the frequency response of a vibrating foundation, such as a compacting plate or the drum of a roller. The method seems promising for predicting the resonant frequency of the roller-soil system and can be used to determine the optimum compaction frequency without site- and roller-specific measurements.

  • 1352.
    Wersäll, Carl
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Influence of Frequency on Compaction of Sand in Small-Scale Tests2013Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Vibratory rollers are commonly used for compaction of embankments and landfills. In a majority of large construction projects, this activity constitutes a significant part of the project cost and causes considerable emissions. Thus, by improving the compaction efficiency, the construction industry would reduce costs and environmental impact. In recent years, rollers have been significantly improved in regard to engine efficiency, control systems, safety and driver comfort. However, very little progress has been made in compaction effectiveness. While the compaction procedure (e.g. layer thickness and number of passes) has been optimized over the years, the process in which the machine compacts the underlying soil is essentially identical to the situation in the 1970s.

    This research project investigates the influence of one crucial parameter, namely vibration frequency of the drum, which normally is a fixed roller parameter. Frequency is essential in all dynamic systems but its influence on the compaction efficiency has not been studied since the early days of soil compaction. Since laboratory and field equipment, measurement systems and analysis techniques at the time were not as developed as they are today, no explicit conclusion was drawn. Frequencyvariable oscillators, digital sensors and computer‐based analysis now provide possibilities to accurately study this concept in detail.

    In order to examine the influence of vibration frequency on the compaction of granular soil, small‐ scale tests were conducted under varying conditions. A vertically oscillating plate was placed on a sand bed contained in a test box. The experiments were carried out in laboratory conditions to maximize controllability. The first test setup utilized an electro‐dynamic oscillator where dynamic quantities, such as frequency and particle velocity amplitude, could be varied in real‐time. The second test setup included two counter‐rotating eccentric mass oscillators, where tests were conducted at discrete frequencies. This type of oscillator has a force amplitude that is governed by frequency.

    The main objectives of the tests were to determine the optimal compaction frequency and whether resonance can be utilized to improve compaction efficiency. Results showed that resonance had a major influence in the electro‐dynamic oscillator tests, where the applied force amplitude is low, and the optimal compaction frequency is the resonant frequency under these circumstances. In the rotating mass oscillator tests, where a high force was applied to the plate, resonant amplification was present but not as pronounced. Since force increase with frequency, the optimal frequency to obtain the highest degree of compaction is very large. In a practical regard, however, frequency should be kept as low as possible to minimize machine wear and emissions while still achieving a sufficient compaction of the soil. Considering the practical issues, it is proposed that surface compactors should operate slightly above the resonant frequency. However, the applicability to vibratory rollers must be confirmed in full‐scale tests.

    The thesis also presents an iterative method to calculate the frequency response of a vibrating plate, incorporating strain‐dependent soil properties. Calculated dynamic quantities are compared to measured values, confirming that the method accurately predicts the response.

  • 1353.
    Wersäll, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Bodare, Anders
    Geo Risk & Vibration Scandinavia.
    Massarsch, Rainer
    Geo Risk & Vibration Scandinavia.
    Frequency content of vertical ground vibrations caused by surface impact2012Konferansepaper (Fagfellevurdert)
  • 1354.
    Wersäll, Carl
    et al.
    Geo Risk & Vibration Scandinavia.
    Bodare, Anders
    Geo Risk & Vibration Scandinavia.
    Massarsch, Rainer
    Geo Risk & Vibration Scandinavia.
    Vibration Source Localization along Railway Tracks2012Inngår i: Noise and Vibration Mitigation for Rail Transportation Systems / [ed] T. Maeda et al., Berlin: Springer, 2012, s. 267-274Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Ground-borne vibration from railway traffic is an increasing problem in urbanized areas and measures are often needed to minimize its effects on the environment. An important question when dealing with railway problems is to identify the source(s) of vibration emitted along the railway track. Once this information is available, it is often possible to mitigate the problem by improving stiffness of the railway track and/or to upgrade worn-out or damaged rail sections and turnouts. This paper describes a method which makes it possible to determine the locations of track sections which are likely to emit strong ground vibration. A purpose-built track-bound vehicle which can be vibrated continuously at different frequencies can identify track sections having unfavorable dynamic foundation conditions. A theoretical concept is proposed to calculate the potential of energy emission from the vehicle moving along the track. Further, an innovative method is presented which makes it possible to determine the location of vibration sources by measurement of ground vibrations from existing railway traffic. This information can be used to determine the location of track sections where remedial measures are needed. Results are presented, illustrating application of the concepts, which can also be applied to other types of vibration problems.

  • 1355.
    Wersäll, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Influence of force ratio and frequency on vibratory surface compaction2016Inngår i: Geotechnics for Sustainable Infrastructure Development / [ed] Phung Duc Long, 2016Konferansepaper (Fagfellevurdert)
  • 1356.
    Wersäll, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Small-Scale Testing of Frequency-Dependent Compaction of Sand Using a Vertically Vibrating Plate2013Inngår i: ASTM geotechnical testing journal, ISSN 0149-6115, E-ISSN 1945-7545, Vol. 36, nr 3, s. 394-403Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Vibratory rollers generally operate at a fixed vibration frequency. It is hypothesized that the compaction of soil could be made more efficient if the frequency could be adapted to specific project conditions. In order to study the applicability to surface compaction, the frequency dependence of compacting dry sand with a vertically vibrating plate was investigated experimentally in 85 small-scale tests. Tests were performed in a test box simulating the free-field condition and with concrete underlying the sand bed. The results show that there is a distinct frequency dependence, implying a significantly improved compaction effect close to the compactor soil resonant frequency. It is suggested that particle velocity is the governing amplitude parameter for vibratory soil compaction, rather than displacement or acceleration. As the soil is compacted, it is also displaced, resulting in surface heave. A larger vibration amplitude implies greater displacement relative to the compacted volume. It was also observed that the compaction and strain-dependent reduction of soil stiffness are closely related.

  • 1357.
    Wersäll, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Bodare, Anders
    Dynamic response of vertically oscillating foundations at large strain2014Inngår i: Computer Methods and Recent Advances in Geomechanics - Proceedings of the 14th Int. Conference of International Association for Computer Methods and Recent Advances in Geomechanics, IACMAG 2014 / [ed] Oka, Murakami, Uzuoka & Kimoto, CRC Press, 2014, s. 643-647Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A method for calculating the dynamic response of a vertically oscillating foundation on soil with strain-dependent properties is developed. Strain-dependent stiffness and damping are incorporated by an iterative procedure, presenting the response in frequency domain. The calculated dynamic displacement amplitudes are compared to small-scale tests using a vertically oscillating plate. The calculated dynamic quantities agree well with measured amplitudes over a wide frequency range.

  • 1358.
    Wersäll, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Rydén, Nils
    Lund Universitet.
    Nordfelt, Ingmar
    Dynapac.
    Frequency Variable Surface Compaction of Sand Using Rotating Mass Oscillators2015Inngår i: ASTM geotechnical testing journal, ISSN 0149-6115, E-ISSN 1945-7545, Vol. 38, nr 2, s. 198-207Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The influence of vibration frequency was studied in 110 small-scale compaction tests conducted using a vertically oscillating plate. The underlying soil was dry sand, or sand close to the optimum water content. The results showed that there is a resonant amplification, providing a slightly higher degree of compaction. Frequency has a major influence on soil compaction. An iterative method for calculating the dynamic response of the plate, incorporating strain-dependent properties of the soil, is also presented. The calculated frequency response agrees fairly well with measured quantities.

  • 1359.
    Wersäll, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Massarsch, Rainer
    Geo Risk and Vibration Scandinavia AB.
    Soil Heave Due to Pile Driving in Clay2013Inngår i: Sound Geotechnical Research To Practice: Honoring Robert D.Holtz  II / [ed] Armin W. Stuedlein, and Barry R. Christopher, American Society of Civil Engineers (ASCE), 2013, s. 481-499Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Soil heave due to pile driving in clay is discussed and, in particular, its influence on adjacent piles. Finite element studies and results of model tests are presented and compared with field measurements. It is demonstrated that in the vicinity of the driven pile, the soil is displaced mainly in the lateral direction, similar to soil subjected to passive earth pressure. General rules of estimating soil heave inside and outside a pile group are examined. A method is proposed for estimating soil heave when driving a group of piles. Practical application of predicting soil heave is illustrated by an example.

  • 1360.
    Wersäll, Carl
    et al.
    Geo Risk & Vibration Scandinavia.
    Massarsch, Rainer
    Geo Risk & Vibration Scandinavia.
    Bodare, Anders
    Geo Risk & Vibration Scandinavia.
    Planning and Execution of Rock Blasting Adjacent to Tunnels2009Inngår i: Environmental Vibrations: Prediction, Monitoring, Mitigation and Evaluation, VOLS I AND II / [ed] H. Xia & H. Takemiya, 2009, s. 749-756Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Prediction and monitoring of vibrations from rock blasting is of practical importance. Damage to rock tunnels caused by blasting is fundamentally different to that of conventional buildings. Different damage mechanisms are discussed as well as methods to monitor the development of cracks by analysis of frequency content. For the assessment of the damage potential it is essential to understand wave propagation in rock and the dynamic response of cavities to vibration excitation. Vibration frequency and wavelength in relation to the size of the cavity are important parameters. Vibration amplification of a circular tunnel to a plane wave is analyzed and guidelines given for practical design applications. Filtering the vibration signal, which is often required in national standards, car. give misleading results for tunnels in rock.

  • 1361.
    Wersäll, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Nordfelt, Ingemar
    Dynapac.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Vibrovältar och jorddynamik - mot effektivare packning2013Inngår i: Bygg & teknik, ISSN 0281-658X, nr 1, s. 32-35Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Packning är den vanligaste jordförstärkningsmetoden och används i stort sett i alla byggprojekt. Ökande byggkostnader och striktare utsläppskrav gör att det finns ett behov av att effektivisera packningsprocessen. I ett doktorandprojekt vid Kungliga Tekniska högskolan (KTH) studeras hur jordpackning med vibrovält kan bli mer effektivt genom att ta hänsyn till  amspelet mellan vält och jord samt vältens och jordens dynamiska egenskaper. Projektet  inansieras av Svenska Byggbranschens Utvecklingsfond (SBUF), Dynapac, Peab och KTH och utförs som ett samarbete mellan KTH, Dynapac och Peab.

  • 1362.
    Wersäll, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Nordfelt, Ingmar
    Dynapac Compaction Equipment AB.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Soil compaction by vibratory roller with variable frequency2016Inngår i: Geotechnique, ISSN 0016-8505, E-ISSN 1751-7656Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Full-scale tests were conducted to study the influence of the operating frequency of a vibratory roller on the compaction of crushed gravel in a controlled environment. Tests were performed at both fixed and variable frequencies. The average densification of the soil was represented by settlement of the ground surface, and depth-dependent density variation before and after compaction was determined by horizontal nuclear density gauge measurements. The resonant frequency was approximately 17 Hz and frequencies in the range 15–35 Hz were tested. The optimum compaction frequency was determined to be around 18 Hz; that is, slightly above resonance, as compared with the standard operating frequency of the roller, 31 Hz. Lower compaction frequency significantly reduces the required engine power and thus fuel consumption and environmental impact, while increasing the lifespan of the roller. Furthermore, the soil closest to the ground surface is loosened at high frequency. This can be avoided with a lower compaction frequency and the need for subsequent static passes can thereby possibly be eliminated.

  • 1363.
    Westberg, Mari
    et al.
    Lund University.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Possible consequences of deterministic design of concrete dams: a comparison to probabilistic design2010Inngår i: Dam Safety: Sustainability in a Changing Environment, 2010Konferansepaper (Fagfellevurdert)
  • 1364. Westberg, Mari
    et al.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    System for concrete dam reliability with respect to foundation stability2012Inngår i: Proceedings of the 3rd International Forum on Risk Analysis, Dam Safety Dam Security and Critical Infrastructure Management, 3IWRDD-FORUM, CRC Press, 2012, s. 87-92Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In order to perform a complete risk analysis of a dam facility, it is necessary to have information about the probability and consequences of failure. To analyze the probability of failure of a concrete dam, all components and all failure modes must be accounted for. This paper presents a methodology for the calculation of the failure probability of a concrete dam with respect to foundation stability where the dam is considered as a system. The system is divided into different levels, where the top event on the "structure level" is failure of the dam. The next level is "monolith level", where each monolith can be considered as an element in a series system of the concrete dam. Below the monolith level is the "failure location level" which describes where the failure occurs, in the concrete-rock contact, in the rock mass or in the concrete. Since it is the weakest of these failure locations that will govern where the failure occurs, each failure location can be seen as elements in a series system. Beneath this level is the "failure mode level" where failure modes such as sliding and rotation also constitute elements in a series system. The "Basic failure modes" are the foundation level in the system. In some situations, the reliability of all failure modes as well as the correlation between failure modes is of importance for the overall reliability. In other situations only the reliability of a dominant failure mode is of importance. A discussion regarding this is given.

  • 1365.
    Westberg Wilde, Marie
    et al.
    ÅF Industry.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE).
    Analysis of concrete dams based on "Probabilistic model code for concrete dams"2015Konferansepaper (Fagfellevurdert)
  • 1366.
    Westerberg, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Behaviour and modelling of a natural soft clay: triaxial testing, constitutive relations and finite element modelling1999Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The main objectives if the research project have been to create an experimental basis for a more general theoretical modelling of Swedish clays and to improve the knowledge of the mechanical behaviour of natural soft clays. Another objective has been to investigate the effects of end restraint on the mechanical behaviour obtained in triaxial tests, by means of numerical simulations. Extensive experimental studies were performed by triaxial tests on a natural soft clay from the city of Norrköping. The results are discussed in detail from a quantitative and qualitative point of view and the effects of the in situ structure of the clay on the mechanical behaviour focused. Undrained and drained shear conditions are investigated. Obtained deformation modes in triaxial tests ar classified and analysed. Soil parameters for constitutive models are evaluated and discussed and requirements formulated for a constitutive model supposed to describe the behaviour of the clay.

  • 1367.
    Westerberg, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Lerors mekaniska egenskaper: experimentell bestämning och kvalitativ modellering med tillämpning på lera från Norrköping1995Licentiatavhandling, monografi (Annet vitenskapelig)
  • 1368.
    Westerberg, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Utmaningar och möjligheter för en förbättrad geoteknik: laboratorieprovning och materialegenskaper idag och imorgon2008Inngår i: Bygg & Teknik, ISSN 0281-658X, nr 1, s. 12-18Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 1369.
    Westerberg, Bo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Albing, Daniel
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Larsson, Rolf
    Swedish Geotechnical Institute.
    Research on strength and deformation properties of Swedish fine-grained sulphide soils2005Inngår i: Proceedings of the 16th International Conference on Soil Mechanics and Geotechnical Engineering: Comptes rendus du XVIème Congrès International de Mécanique des Sols et de la Géotechnique : [16 ICSMGE, Osaka, Japan, 12 - 16 September 2005], Rotterdam: Millpress , 2005, Vol. 2, s. 623-626Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A recently started research project concerning strength and deformation properties of Swedish fine-grained sulphide soils is presented. The scope of study is outlined. The overall purpose of the project is to find suitable testing methods in field and laboratory to determine reliably the mechanical properties of fine-grained sulphide soils. In this paper, some test results of undrained shear strength of sulphide soils, determined with different test methods at two test sites, is presented. The results confirm that there is a need for calibration of the different evaluation methods in order to obtain relevant values in fine-grained sulphide soils.

  • 1370.
    Westerberg, Bo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Albing, Daniel
    Larsson, Rolf
    Swedish Geotechnical Institute.
    Strength and deformation properties of fine-grained sulphide soil2005Inngår i: Proceedings: XVI ICSMGE Osaka 2005, Rotterdam: Millpress , 2005, s. 623-636Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Sulphide soil is the dominating fine-grained soil type along the east coast of the northern part of Sweden. A sulphide soil typically consists of clay and silt fractions with various and smaller content of sand. Sulphide soil may contain high amounts of iron mono sulphides (FeS) and organic content up to about 10%. A fine-grained sulphide soil normally shows low strength and high compressibility. Previous research concerning strength and deformation properties of Swedish fine-grained soils has very little included sulphide soil. It has been found that field and laboratory methods used to determine properties of other fine-grained soils, are often not suitable for sulphide soil.In this paper results from field and laboratory testing of fine-grained sulphide soil are presented and discussed. In the field, field vane tests, CPT-tests, dilatometer tests, seismic CPT-tests and undisturbed sampling are conducted. In the laboratory, triaxial tests, direct shear tests, oedometer tests, CRS-oedometer tests, routine tests of basic geotechnical properties and tests to determine chemical properties are done. In the laboratory, testing is carried out in room temperature as well as for in situ soil temperature for samples handled either at normal air conditions or at air free conditions.The main purpose of the research project is to find suitable testing methods in field and laboratory to determine mechanical properties of fine-grained sulphide soils. This includes how the results should be interpreted and evaluated and how samples should be sampled, transported, stored, handled and tested. In the paper the first part of the project is reported, including comparisons between properties and parameters determined in field and in laboratory. Effects on mechanical properties of testin g in room temperature versus in situ soil temperature and effects of handling the sample at air free conditions or not, are presented.

  • 1371.
    Westerberg, Bo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Andersson, Mattias
    SGI/LTU.
    Undrained shear strength and compression properties of Swedish fine-grained sulphide soils2009Inngår i: Proceedings of the 17th International Conference on Soil Mechanics and Geotechnical Engineering: the academia & practice of geotechnical engineering : 5-9 October 2009, Alexandria, Egypt = Comptes rendus du 17ème Congrès International de Méchanique des Sols et d'ingénierie Géotechnique : Le monde universitaire et la pratique en géotechnique : 5-9 Octobre 2009, Alexandrie, Egypte / [ed] M. Hamza; M. Shahien; Y. El-Mossallamy, Amsterdam: IOS Press, 2009, Vol. 1, s. 72-75Konferansepaper (Fagfellevurdert)
  • 1372.
    Westerberg, Bo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Edeskär, Tommy
    Gummiklipp: ett alternativt konstruktionsmaterial2001Inngår i: V-byggaren : väg- och vattenbyggaren, ISSN 0283-5363, nr 4, s. 38-39Artikkel i tidsskrift (Annet vitenskapelig)
  • 1373.
    Westerberg, Bo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mácsik, Josef
    LTU.
    Laboratorieprovning av gummiklipps miljögeotekniska egenskaper2001Rapport (Annet vitenskapelig)
    Abstract [sv]

    Syftet med denna undersökning var att bestämma tekniska och miljötekniska egenskaper hos gummiklipp. Med detta som underlag har en miljögeoteknisk bedömning utförts avseende användning av materialet som lättfyllnad i vägbankar och dränering i askdeponier. Vidare identifieras typiska och dimensionerande värden på tekniska och miljötekniska parametrar. Genom laboratorieförsök har de tekniska egenskaperna kompression, densitet, permeabilitet och skjuvhållfasthet undersökts för gummiklipp med storleken 50x50 mm2. En nyutvecklad "multiapparat" med diametern 64 cm och initiella provhöjden 40-60 cm har använts för försöken. Vad avser hållfasthetsegenskaper har även gummigranulat med storleken 1-3 mm och 0-12 mm provats i en konventionell direkt skjuvapparat. Miljötekniska egenskaper har undersökts för gummiklipp med avseende på innehåll och lakbarhet av metaller, svavel och polyaromatiska kolväten (PAH). Sammantaget gäller att materialet, med avseende på undersökta egenskaper, bedöms ha goda förutsättningar att dels kunna nyttjas som ett lättfyllnadsmaterial exempelvis vid kompensationsgrundläggning eller som ett kombinerat lättfyllnads- och tjälisoleringsmaterial och dels kunna nyttjas som ett dräneringsmaterial i botten på en askdeponi.

  • 1374.
    Westerberg, Bo
    et al.
    Swedish Geotechnical Institute, Linköping, Sweden.
    Müller, Rasmus
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik. Tyréns AB, Sweden.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Evaluation of undrained shear strength of Swedish fine-grainedsulphide soils2015Inngår i: Engineering Geology, ISSN 0013-7952, E-ISSN 1872-6917, Vol. 188, s. 77-87Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In Swedish practice, there is a long tradition of evaluating undrained shear strength from fall-cone tests and field vane tests. During the last 20 years cone penetration tests have also become widely used. However, the results from all these test methods have to be evaluated using empirical factors. The factors generally used for Swedish clays are related to liquid limit and overconsolidation, but they are not applicable to all types of fine-grained soils and can often be improved by local calibration for the particular type of soil in the area of current interest. For this calibration, the results of direct simple shear tests and/or triaxial tests in the laboratory are normally used. This paper presents an evaluation for Swedish fine-grained sulphide soils, for which a general correction factor of 0.65 for field vane tests and fall-cone tests, a cone factor Nkt of 20.2 for cone penetration tests and a relation cu,DSS/(σ′cOCR−0.2) of 0.28 have been found. No correlations were found between these empirical factors and the clay content, liquid limit or organic content, but a relationship was found between the overconsolidation ratio and both the cone penetration test and the field vane test. The sulphide soils in question are found in northern Sweden along the coast of the Gulf of Bothnia. They aremostly classified as organic silt or organic clay,which is normally silty.

  • 1375. Westerberg, Bo
    et al.
    Pousette, Kerstin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Rogbeck, Yvonne
    SGI.
    Andersson, Mattias
    SGI.
    Norrman, Tomas
    Ramböll Sverige.
    Laboratory tests of stabilised sulphide soil from Northern Sweden2005Inngår i: Deep mixing '05: International Conference on Deep Mixing : best practice and recent advances, Swedish Deep Stabilization Research Centre , 2005Konferansepaper (Annet vitenskapelig)
  • 1376.
    Westerberg, Bo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Ballastrening och bankettrensning på Malmbanan: en fält- och laboratoriestudie2001Rapport (Annet vitenskapelig)
    Abstract [sv]

    Syftet med studien var dels att bestämma tekniska egenskaper(kornfördelning, densitet, vattenkvot, infiltrationskapacitet, permeabilitet, kapillaritet) hos ballast och bankettens överskottsmassor genom fältförsök och genom laboratorieförsök och dels att baserat på bestämningen av de tekniska egenskaperna hos ballast och bankettens överskottsmassor undersöka behovet av och nyttan med ballastrening och bankettrensning. I studien har förhållandena i fyra sektioner längs Malmbanan, två på vardera sträckan Ljuså-Gransjö och Nattavaara-Kilvo, undersökts genom fältförsök och laboratorieförsök. Av de slutsatser som dragits i studien kan följande nämnas: Det nuvarande kriteriet (dvs när andelen partiklar, d<31.5 mm, överstiger 40 viktsprocent) för när ballastrening skall utföras bör ifrågasättas. Även andra faktorer (kriterier) än andelen partiklar mindre än 31.5 mm bör tas i beaktande för att avgöra när behov av rening finns. Sådana faktorer skulle kunna vara infiltrationskapacitet, porfyllnadsgrad (volymandelen finkornigt material i porutrymmet mellan makadamstenarna), tjällyftningsbenägenhet, dynamiska egenskaper, underballastens beskaffenhet, etc. Flera eller andra siktgränser (än 31.5 mm) och krav på maximal tillåten andel skulle kunna införas. Dessa gränser skall då baseras på olika egenskaper hos ballasten som kan förändras på ett negativt sätt vid en för hög halt av finkornigt material. Baserat på de faktorer som undersökts i denna studie kan konstateras att ballastrening var nödvändig att utföra för att skapa tillräcklig tjocklek på makadamballast och för att rena den nedre delen av ballasten men troligen inte nödvändig med tanke på dräneringsförmåga och tjälfarlighet. Baserat på de faktorer som undersökts i denna studie kan konstateras att bankettrensning var nödvändig att utföra för att ta bort stora mängder onyttiga överskottsmassor, vilket bl a medför att stabiliteten för banvallen ökar, men troligen inte nödvändigt med tanke på dräneringsförmåga och tjälfarlighet.

  • 1377.
    Wetterheim, Hanna
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Byggnadsteknik.
    Josefsson, Hiba
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Byggnadsteknik.
    Sulfidjord – En analys av förbelastning och vertikaldränering med förbelastning2018Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med detta examensarbete är att undersöka två olika grundförstärkningsmetoder på sulfidjord, vertikaldränering med förbelastning samt förbelastning, och komma fram till vilken metod som är lämpligast med avseende på sättningar, portryck och hållfasthet. Anledningen till detta arbete är att sulfidjord har dålig bärighet och är sättningsbenägen, vilket gör det till en nödvändighet att förstärka jorden innan byggnation. Sulfidjord har dålig miljöpåverkan vid kontakt med syre och ska inte grävas upp. Därför är de två förbelastningsmetoderna bra att använda på denna typ av jord. I Sverige finns jorden främst längs Norrlandskusten, vilket är det område som rapportens undersökningar kommer från.Datainsamlingsmetoderna som legat till grund för arbetet har huvudsakligen samlats in genom kvalitativa insamlingsmetoder i form av litteraturstudier av tidigare forskningsarbeten samt intervju med sakkunnig geotekniker. Genom dokumentanalys har kvantitativ insamlingsmetod använts, då insamling av mätvärden från undersökningar genomförts för att ta fram ett resultat.Resultatet sammanställdes och visade att vertikaldränering med förbelastning är en mer optimal förstärkningsmetod att utgå från, utifrån de faktorer som har undersökts. Vid vertikaldränering med förbelastning går tidsförloppet fortare för sättningar och protrycksutjämning. De olika försöken har sammanställts i tabell och ett resultat kunde fås.De skrivna frågeställningarna som behandlades och besvarades i rapporten visade på att vertikaldränering har en snabbare inverkan. Tid kan sparas om metoden väljs och byggnation kan därefter göras på den styvare jorden. Denna rapport har begränsats då den bara behandlar två specifika förstärkningsmetoder. Ekonomiska aspekter och miljöpåverkan tas inte med i rapporten för att inte riskera att ämnet blir stort. Nyckelord: förbelastning, förstärkningsmetoder, sulfidjord, vertikaldränering och överlast.

  • 1378.
    Wibling, Anna
    et al.
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avd för naturvetenskap, lantmäteri- och maskinteknik.
    Olsson, Marie
    Högskolan Väst, Institutionen för ingenjörsvetenskap, Avd för naturvetenskap, lantmäteri- och maskinteknik.
    Mindre avvikelse i detaljplan enligt fastighetsbildningslagen: En jämförande studie mellan det statliga och det kommunala lantmäteriet2014Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Detta examensarbete behandlar begreppet ”mindre avvikelse” inom detaljplan. I 3 kap. 2 § fastighetsbildningslagen, FBL återfinns definitionen av när en sådan avvikelse får göras och syftar till fastighetsbildningsåtgärderna fastighetsreglering, sammanläggning, klyvning samt avstyckning. Åtgärder som dessa medförande mindre avvikelse inom detaljplan eller områdesbestämmelser kan ske endast om det inte är i strid mot plan och är förenliga med dess syfte.

    En mindre avvikelse tillkommer genom en slutförd lantmäteriförrättning där lantmäteriet är sista instans och har ansvar för att besluta om den mindre avvikelsen bör godtas eller ej. Syftet med examensarbetet är att belysa eventuella olikheter mellan statligt och kommunalt lantmäteri i förhållande till slutförda förrättningar där mindre avvikelse inom detaljplanelagt område gjorts. Vidare har vi undersökt vad dessa skillnader kan bero på och vad som kan göras för att minska antalet avvikelser inom detaljplanelagt område. Underlag för denna studie har varit förrättningsakter från Göteborgs kommunala lantmäteri, inkomna och slutförda under en tvåårsperiod samt från Kungsbackas och Eskilstunas statliga lantmäterier, inkomna och slutförda under en fyraårsperiod. Sammanlagt har vi gått igenom 2099 förrättningsakter med fastighetsbildningsåtgärder där 551 stycken berörde 3 kap. 2 § FBL samt var belägna inom detaljplanelagt område. Av dessa var det i sin tur sammanlagt 49 stycken som innehöll en mindre avvikelse. Denna studie visar att det oftare förekommer mindre avvikelser i förrättningar handlagda inom det statliga lantmäteriet. Detta beror huvudsakligen på att det statliga lantmäteriet inte har samma möjligheter att medverka i planprocessen i samma utsträckning som den kommunala lantmäterimyndigheten. För att minska antalet mindre avvikelser från detaljplan är ett tätare samarbete mellan dem som upprättar planerna och lantmäteriet som genomför dem, en bra utgångspunkt. Det är också viktigt att lantmäteriet inte godtar förrättningar som resulterar i mindre avvikelse, vilket gör att antalet mindre avvikelser minskar. Om mer arbete läggs på genomförandefrågorna när detaljplanen upprättas kommer det leda till ett snabbare genomförande. Ett snabbt genomförande innebär kortare handläggningstid för  förrättningslantmätaren, vilket är en fördel för fastighetsägaren som är den som får betala för fastighetsbildningsförrättningen 

  • 1379.
    Widenfalk, Lennart
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser.
    Håkansson, S.
    Luleå tekniska universitet.
    Mercury, an indicator of sources of ore-bearing boulders ( Sweden).1983Inngår i: Geologiska föreningens i Stockholm förhandlingar, ISSN 0016-786X, Vol. 105, nr 2, s. 155-159Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The mercury content of sulfides shows a regular trend on both local and regional scale in the Skellefte district. For this reason sulfide concentrates from thirteen ore boulders were analyzed for Hg, Zn and Cu. The ratio Hg/Zn in sphalerite and Hg/Cu in chalcopyrite as well as the amount of mercury in pyrite appear to serve well as fingerprints of the boulders

  • 1380. Wiklund, J.
    et al.
    Rahman, Mashuqur
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Håkansson, U.
    In-line rheometry of micro cement based grouts - a promising new industrial application of the ultrasound based uvp plus pd method2012Inngår i: Applied Rheology, ISSN 1430-6395, E-ISSN 1617-8106, Vol. 22, nr 4, s. 42783-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Measurements of the viscosity of non-Newtonian fluids and suspensions having a solid volume fraction of about 30% or more is of major interest from an industrial point of view. Cement paste and cement grouts for injection grouting applications, with water to cement ratios typically in the range of 0.4 and 0.6 - 0.8 by weight, are two examples of industrial fluid systems. Few in-line techniques are available on the market that can be used for these fluid systems and under realistic field conditions. The so-called UVP+PD in-line rheometry method combining the Ultrasound Velocity Profiling (UVP) technique with Pressure Difference (PD) measurements is a promising new tool for industrial applications. This paper presents an initial pre-study that aims to demonstrate the feasibility of the UVP+PD method using cement grouts for process monitoring and control of grouting applications under realistic field conditions. The UVP+PD method was tested and found successful for continuous inline measurements of concentrated micro cement-based grouts with water/cement ratios of 0.6 and 0.8. The test set-up consisted of a combination of an experimental " flow loop" and a conventional field grouting rig - UNIGROUT, from Atlas Copco. The rheological properties were determined, directly in-line and the parameters obtained were subsequently compared with off-line measurements using a conventional rotational rheometer.

  • 1381. Wiklund, Johan
    et al.
    Rahman, Mashuqur
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Håkansson, Ulf
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    In-line rheometry of dense cement suspensions using an Ultrasonic Velocity Profiling with combined Pressure Difference Method (UVP-PD)2011Inngår i: Applied Rheology, ISSN 1430-6395, E-ISSN 1617-8106Artikkel i tidsskrift (Annet vitenskapelig)
  • 1382. Wilde, Marie Westberg
    et al.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    System Reliability of Concrete Dams with Respect to Foundation Stability: Application to a Spillway2013Inngår i: Journal of Geotechnical and Geoenvironmental Engineering, ISSN 1090-0241, E-ISSN 1943-5606, Vol. 139, nr 2, s. 308-319Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Structural reliability analysis is not widely used for the design and assessment of concrete dams. In this paper, the system reliability of a spillway structure consisting of two monoliths is calculated. Limit state functions are defined from the failure modes sliding in the concrete rock contact, sliding in the rock mass, and adjusted overturning. Random variables in the limit state functions are defined by stochastic distributions. These are defined based on site investigations and laboratory tests from samples taken at the dam. Simulations and information from the literature are used for the remaining variables. The safety index is calculated by the first-order reliability method for each failure mode and monolith, and the system reliability is approximated by direct integration of the bivariate normal distribution. The output is the safety index including associated sensitivity values at the single failure mode, monolith, and system levels. The results show that the system safety is governed by a persistent rock joint beneath one monolith. A system reliability analysis is found to be a useful tool in the dam risk management process as it can be used to calculate the probability of failure and to identify important failure modes and variables.

  • 1383.
    With, Christoffer
    et al.
    KTH, Tidigare Institutioner, Byggvetenskap. KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Bahrekazemi, Mehdi
    KTH, Tidigare Institutioner, Byggvetenskap. KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Bodare, Anders
    KTH, Tidigare Institutioner, Byggvetenskap. KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Mätningar av tåginducerade markvibrationer i Kåhög före och efter motåtgärd2004Konferansepaper (Annet vitenskapelig)
  • 1384.
    With, Christoffer
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Bahrekazemi, Mehdi
    Golder Associates AB, S-10460 Stockholm, Sweden .
    Bodare, Anders
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Wave barrier of lime-cement columns against train-induced ground-borne vibrations2009Inngår i: Soil Dynamics and Earthquake Engineering, ISSN 0267-7261, E-ISSN 1879-341X, Vol. 29, nr 6, s. 1027-1033Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a comparison between measured train-induced ground vibrations in the free-field before and after countermeasures had been taken at Kahog near Gothenburg in Sweden. A wave barrier of lime-cement columns was constructed parallel to the railway in order to reduce the ground-borne vibrations inside nearby buildings. On top of the barrier an embankment was built to reduce air-borne vibrations. Due to the wave barrier design, part of the energy content of the waves was expected to be reflected by the screen and transmitted energy was expected to be partly scattered. Contribution from the noise-embankment was not thought likely but could not be ruled out due to its fairly large mass and its close proximity to the railway. The effect of the mitigating measures resulted in a 67% reduction of the maximum particle velocity at 30 m and 41% at 60 m from the railway. A simple two-dimensional finite element model has been used to Study the relative importance of the wave barrier and the noise-embankment as contributors to the mitigation recorded of the ground vibrations in the field. It is concluded with respect to ground vibrations that both the barrier and the embankment had a mitigating effect but that the contribution from the barrier dominated. Furthermore, it is seen from the field results as well as the Simulation that the effect of the mitigating action is reduced with increasing distance from the railway.

  • 1385.
    With, Christoffer
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Bodare, Anders
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Lime-cement columns as wave barrier against train-induced vibrations2007Inngår i: Geotechnical Engineering in Urban Environments: Proceedings of the 14th European Conference on Soil Mechanicsand Geotechnical Engineering / [ed] V. Cuéllar, E. Dapena, E. Alonso, J.M. Echave, A. Gens, J.L. de Justo, C. Oteo, J.M. Rodríguez-Ortiz, C. Sagaseta, P. Sola, A. Soriano, 2007, s. 1397-1401Konferansepaper (Fagfellevurdert)
  • 1386.
    Xintao, Liu
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geodesi och geoinformatik.
    Bin, Jiang
    Geomatics, University of Gävle.
    Defining and generating axial lines from street center lines for better understanding of urban morphologies2012Inngår i: International Journal of Geographical Information Science, ISSN 1365-8816, Vol. 26, nr 8, s. 1521-1532Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Axial lines are defined as the longest visibility lines for representing individual linear spaces in urban environments. The least number of axial lines that cover the free space of an urban environment or the space between buildings constitute what is often called an axial map. This is a fundamental tool in space syntax, a theory developed by Bill Hillier and his colleagues for characterizing the underlying urban morphologies. For a long time, generating axial lines with help of some graphic software has been a tedious manual process that is criticized for being time consuming, subjective, or even arbitrary. In this paper, we redefine axial lines as the least number of individual straight line segments mutually intersected along natural streets that are generated from street center lines using the Gestalt principle of good continuity. Based on this new definition, we develop an automatic solution to generating the newly defined axial lines from street center lines. We apply this solution to six typical street networks (three from North America and three from Europe), and generate a new set of axial lines for analyzing the urban morphologies. Through a comparison study between the new axial lines and the conventional or old axial lines, and between the new axial lines and natural streets, we demonstrate with empirical evidence that the newly defined axial lines are a better alternative in capturing the underlying urban structure.

  • 1387.
    Yaghoobi Rafi, Jalaleddin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Design approaches for grouting of rock fractures; Theory and practice2013Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Currently, cement base grout is used widely for sealing of the rock fractures in order to decrease the permeability of rock mass. Grouting procedure is one of the main tasks in cycle of rock excavation. In addition, huge amount of grout should be used during dam construction in order to seal the bedding and embankment walls. Therefore, considering the effect of grouting in duration and cost of the project, improving the design methods seems essential.

    In successful grouting the goal is to achieve the required sealing of fractures while avoiding ground movement due to applied pressure. Empirical methods have been developed to decide the pumping pressure, grout mix properties and stop criteria in order to fulfill requirements of successful grouting but there are ambiguities in using them and performance of them have been questioned. In these methods, assumptions and criteria are based on rules of thumbs and experiences from previous projects. The main uncertainties connected to these methods are identifying amount of grout spread and state of the fracture.

    Theoretical approach is an analytical solution which provides the chance for estimation of penetration length of the grout in real time. Furthermore, void filling fracture aperture and trend of the grout flow are estimated. As the development of this theory, elastic and ultimate jacking limits have been established based on the estimated penetration length. Therefore, it is possible to identify jacking of the fracture and estimate the state of the fracture in real time. 

    In this research work, performance of this theoretical approach which is called “Real Time Grouting Control Method” has been validated through case studies. Properties of the used material, data for pressure and flow in addition to geological characteristics have been gathered from projects in sedimentary rock (Gotvand Dam in Iran and THX Dam in Laos) and hard rock (City Line Project in Sweden). This theory made it possible to observe overflow of grout and jacking of the fractures in sedimentary rock. In place of hard rock with mostly vertical fractures, this theoretical approach confirms usage of higher pressure which will shorten the grouting time.

    In this research work, variation in properties of the grout mix during grouting has been neglected. moreover, orientation of the fracture and its deformation due to injection pressure are not considered. Despite these assumptions, the results were promising and performance this approach in estimation of grout spread and identifying jacking of the fracture has been verified.

  • 1388.
    Yaghoobi Rafi, Jalaleddin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Study of Pumping Pressure and Stop Criteria in Grouting of Rock Fractures2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Today practice of grouting is based on empirical approaches in that, pumping pressure and stop criteria are determined by benchmarking similar projects. Considering a maximum limit for grouting pressure would allow applying a relatively high pressure that may lead to jacking of the fracture or even uplift of the rock mass. On the other hand, keeping the pressure lower than the overburden, in order to avoid any deformation, will prolong grouting process. Determination of pumping pressure is more complicated considering the induced energy to the rock fracture due to combination of the injected volume and pumping pressure. In other word, pressurizing large volume of the injected grout with a low pumping pressure establish the same force inside the fracture as the high applied grouting pressure on small injected volume do. Therefore, an stop criterion to limit grouting volume along with grouting pressure, which is a hyperbola trimming maximum pressure-maximum volume limits and  named as grout intensity number (GIN), has been defined. However, in using this stop criterion and at completion point, the state of the fracture and the distance that grout spread inside the fracture are unknown. As a theoretical approach, examining the flow of the Bingham fluid in network of fractures led to development of a numerical model and later an analytical solution, which enabled estimation of distance that grout spread in the fractures in real time. Finally, theoretical curves to limit elastic and ultimate jacking were established to limit grout pressure in correlation with depth of grout penetration by considering the state of the fracture.  

    Despite empirical and theoretical developments, determination of optimum grouting pressure is still challenging. In this study, In addition to examining performance of the analytical solution in estimation of grout spread and distinguishing onset of fracture jacking, the goal is coming up with recommendations for selection of optimum grouting pressure, by examining mechanism of elastic jacking. For this purpose, negative aspects of fracture deformation, which are increase of grouting time and remaining transmissivity, were quantified and discussed against its positive effect on increase of penetrability. By that, application of a relatively high pressure was recommended in order to opening of the fracture to a permitted level, with purpose of increasing penetrability while considering negative effects of elastic jacking. The stop criterion is defined as the grouting time of achieving the required distance of grout spread at the highest applicable grouting pressure.

    In examining empirical methods, in grouting of fractures in deep levels, pressure-depth graph suggests usage of higher pressure in compare with the estimated pressure by theory while GIN method is conservative. In further studies GIN was estimated analytically and applying a relatively high grouting pressure in order to opening the fracture, up to attaining the hyperbola, and continuation of grouting with decreasing trend, in order to bringing the fracture back to its initial size at refusal, were proposed. Complexity of using this methodology in compare with theoretical approach was discussed.

    As the future work, there is a need to verify the results in the field, and to confirm well performance of this analytical solution in different geologies. Examining variation of grout mixture properties during grouting program as well as significance of simplification of geological pattern to a single horizontal fracture, in that grout flow radially, are among other future studies that can develop this theoretical application further.  

  • 1389.
    Yaghoobi Rafi, Jalaleddin
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Fereidouni, Hamidreza
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Robustness of Theories and Newly Developed Methods for Cement Base Grouting Works2012Konferansepaper (Annet vitenskapelig)
  • 1390.
    Yaghoobi Rafi, Jalaleddin
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Applicability of using GIN method, by considering theoretical approach of grouting design2015Inngår i: Geotechnical and Geological Engineering, ISSN 0960-3182, E-ISSN 1573-1529, Vol. 33, nr 6, s. 1431-1448Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the practice of grouting of fractured rock, currently, empirical methods are used. Amongst them, the GIN method is popular mostly in Europe and has been tried in many projects. The concept of this method is to limit the combination of pressure and injected volume to a specific grout intensity number in order to control the energy induced in the rock fractures and to avoid uplift. However, difficulties in employing this method have been reported, which are mainly due to uncertainties in recognizing the distance of grout penetration and the state of the fractures during grouting and at the completion grouting. In this paper, the purpose has been examining the applicability of the GIN method by defining the characteristic curve of the P·V diagram (referred to here as the hyperbola) and suggesting appropriate completion criteria based on the radius of grout spread around the borehole. This will provide the chance to assign a permitted level of fracture deformation (or jacking) to the GIN by considering the formulation of fracture deformation based on grout propagation in a previously developed theoretical approach by Stille et al. (Geotech Geol Eng 30:603–624, 2012) as a part of the Real Time Grouting Control Method. Thus, in attaining the hyperbola, the identified radius of grout spread is achieved and the resulting fracture deformation at this completion point can be beneficial in improving penetrability. However, if the full extent of this deformation extends beyond the grouted zone, part of the fracture may remain un-grouted, and this will affect the sealing efficiency of the grouting program. This may be continued by selecting a smaller GIN and reducing the grouting pressure as the real time pressure–volume plot moves along the hyperbola, which will bring the fracture back to its initial state as grouting approaches the completion point, i.e. when the grout has spread to the desired distance. This hypothesis has been examined against the grouting works performed in three different real projects, for which the grouting parameters can be determined from the available grouting records. It is concluded that the GIN used in practice was much higher than the theoretically estimated values obtained through the proposed analytical solution. Furthermore, in the grouting of fractures close to the surface, the radius of grout spread impacts the GIN significantly, and only a limited grouting pressure is applicable, thus in using split spacing technique in such circumstances, different GINs should be selected for different sets of boreholes to obtain enough propagation at the maximum applicable pressure. The introduced analytical solution introduced in this paper can be a useful procedure for designing the GIN based on the grout spread. Nevertheless, it becomes complicated in dealing with fracture deformation. In a difficult grouting case where the demand for sealing is high, the recommendation is to use the proposed theoretical approach, which provides detailed information during the actual grouting procedure, by estimation of the radius of grout spread and the state of the fracture in real time

  • 1391.
    Yaghoobi Rafi, Jalaleddin
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Control of rock jacking considering spread of grout and grouting pressure2014Inngår i: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 40, s. 1-15Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper describes a theoretical approach for monitoring fracture dilatancy (or “jacking”) during grouting. From this, a methodology to optimize the grout pumping pressure has been developed, based on the required penetration length (i.e. the distance that the grout spreads from the grout hole into the network of fractures within the rock mass). Empirical rules are put forward to prevent the damage that may result from uncontrolled deformation (Jacking) of the fractures, by limiting either pumping pressure or the injected grout volume, or by a combination of both. The state of the fractures and the spread of the grout when these limits are reached are discussed. The theoretical approach, which is referred to here as the Real Time Grouting Control Method, enables the estimation of grout penetration length or “spread” in real time. This gives an opportunity to monitor fracture dilation as it happens and, for the purpose of this paper, the allowable limits of elastic deformation and jacking have been estimated based on the grout spread. Two case histories are analyzed, for which the physical reaction of the fracture deformation with time and grout spread are determined from the recorded pressure and flow. By comparing the observed physical reaction with the theories for jacking presented here, the Real Time Grouting Control Method has been validated, and it is shown that this theoretical approach is superior to commonly used empirical methods, in that it allows the optimization of the pumping pressure to achieve a given penetration length in the shortest time and with an acceptable fracture dilatancy. This approach is a major step forward in customizing grouting works.

  • 1392.
    Yaghoobi Rafi, Jalaleddin
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Bagheri, Mehdi
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Applying Real Time Grouting Control Method in Sedimentary Rock2012Inngår i: Grouting and deep mixing: proceedings of the fourth International Conference on Grouting and Deep Mixing, February 15-18, 2012, New Orleans, Louisiana, American Society of Civil Engineers (ASCE), 2012, s. 1450-1459Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We report on preliminary studies of low (14 at.%) and high (53at.%) concentration Mn doped MgO films deposited by co-sputtering from metallic Mn and Mg targets. The structural, surface morphologies and magnetic properties of the films of different thickness were studied. All the as grown films are found to be amorphous and film surfaces are found to be flawless and homogeneous. We observe at room temperature robust ferromagnetic loops with a saturation magnetization value that is a function of film thickness reaching a maximum of ≃38.5 emu/cm3 in the Mn0.53Mg0.47O film at a thickness of ≃92 nm. In thicker films room-temperature ferromagnetic ordering is suppressed and eventually at a thickness around 120nm the expected diamagnetism of the bulk appears. The origin of ferromagnetism may be attributed to cation defects at the Mg-site.

  • 1393.
    Yaghoobi Rafi, Jalaleddin
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Tsuji, Masakuni
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Theoretical approaches in grouting design: estimation of penetration length and fracture deformation in real time2013Inngår i: Bergmekanikdagen, 2013Konferansepaper (Annet vitenskapelig)
  • 1394.
    Yaghoobi Rafi, Jalaleddin
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Tsuji, Masakuni
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Stille, Håkan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Theoretical Approaches in Grouting Fractures of the Rock Mass: Theories and Applications2013Inngår i: 47th US Rock Mechanics / Geomechanics Symposium, American Rock Mechanics Association (ARMA), 2013, s. 1731-1737Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Currently there is a great deal of specific attention on improving the grouting methods since optimizing the grouting process will have significant impact on performance and economy of projects as well as safeguarding the purity of nature. The main problem with existing grouting method is lack of knowledge about the spread of grout, i.e. there is no clue if the grout has been penetrated enough or if it has been over spread. Also the state of fractures during grouting is unknown. In the last decade, theoretical approach has been developed which enables estimation of the grout spread in real time. Furthermore, by replacing the estimated penetration length with injected volume, dilation of the rock fractures is monitored in real time. In this paper, this analytical solution has been examined and competency of its application has been discussed. Implementing this theory with data from City Line project confirms the usage of high applied pressure in this project which will lead to shortening of the grouting time.

  • 1395.
    Yang, Ting
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Borehole sealing with expandable buffer clays in HLW disposal: Lab-scale performance2015Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Two basically different multibarrier concepts for high-level radioactive waste (HLW) are the often cited KBS-3 V/H concepts, for isolating nuclear waste at 400-600 m depth and Very Deep Boreholes concepts (VDH) for placement at 2000-4000 m depth. Both make use of expandable clay as isolating medium of canisters with HLW and as backfill material in shafts and tunnels in repositories for safe disposal of such waste. This licentiate thesis is based on three papers related to the properties of clays for use as engineered barriers, and to their performance at geological disposal. The first paper deals with the buffer criteria for the two disposal concepts. In this paper the possibilities and limitations of using clays of montmorillonite-, saponite- and mixed layer clay type are considered. The second paper discusses the swelling property and permeability of Na-montmorillonite clays (MX-80, GMZ) and illite-smectite mixed layer clay (Holmehus) saturated and percolated by distilled water and a salt solution. The third paper describes a lab-scale performance of VDH holes sealing using Holmehus clay. In this paper, methods for solving the problem of too quick hydration of the dense clay are investigated and evaluated.

  • 1396.
    Yang, Ting
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Maturation of Clay Seals in Deep Bore Holes for Disposal of Radioactive waste: Theory and Experiments2017Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    KBS-3 and very deep borehole (VDH) concepts are two major types of long-term geologicaldisposal methods for high-level radioactive waste (HLW) isolating from the biosphere. TheKBS-3V concept for isolating the HLW at the depth of 400-500 m, is the officially proposedoption in Sweden and has been the subject of considerable research in the past few decades,while the VDH concept was considered as an option in the 1950s but later became discouragedbecause of insufficient experience in drilling technology. The greatest merit of the VDHconcept is that the almost stagnant groundwater in the deep boreholes prevents the transport ofthe possible release of radionuclides into the rock or up to the ground level. Since variousdisadvantages of the KBS-3V concept were found in previous research, the superiority of VDHconcept attracted the researchers to continue studying it into the late 1980s.The geological repositories of both of KBS-3V and VDH types primarily consist of a naturalbarrier (host rock) and of an engineering barrier (also known as a buffer/backfill barrier).According to the principle of IAEA and national relative research organizations, thebuffer/backfill material should have low permeability and good expandability, as well assuitable physical and sealing properties.The thesis concerns the VDH concept and is focused on the construction and performance ofthose parts of the sealed repository that are not affected by high temperature or gamma radiation.In the lower part of a VDH repository, the clay packages containing HLW will be exposed tohigh temperature (100-150 􀄇 ) in the borehole and to highly saline groundwater. In theinstallation phase of HLW, the groundwater will be pumped out and replaced by medium-softsmectite clay mud in which the HLW packages are installed vertically. During the hydrationand maturation of the clay components, the microstructural reorganization, water transport,migration of clay particles and redistribution of the density of the components take place. Thematuration determines the transient evolution of the clay seals and influences the rheologicaland soil mechanical behavior in the installation phase. The maturation of clay system alsodetermines their ultimate sealing potential of VDH repositories.This study presents the work carried out for investigating the maturation of the buffer-backfillclay in the HLW deep borehole. Initially in the study three types of clays, the Namontmorillonite,magnesium-rich and illite-smectite mixed layer clays, were examined for estimating their performance as the barrier candidate material. This is mainly presented in theliterature review. The experimental study was conducted on montmorillonite GMZ clays andI/S mixed-layer Holmehus clay. The expandability and permeability tests were carried out forinterpretation of the recorded swelling development and assessment of the effect of the salineconditions, with the goal of deriving a relationship between swelling pressure and hydraulicconductivity for different dry densities. The maturation tests of initially fully-saturatedHolmehus clay and partly saturated GMZ clay were performed. During the tests, the shearstrength mobilised by the relative movement of densified mud and migrated dense clay -contained in a perforated central tube - were determined. According to the results of shearstrength tests, the maximum operation time or the number of clay packages to be placed in asingle operation was evaluated, whilst the suitable saturation degree of the dense clay wasdiscussed as well.A model of the maturation of initially water-saturated clay seals based on Darcy’s law wasworked out and the evolution of the clay components in a lab-scale borehole using Holmehusclay were performed and compared with the experimental recordings. Good agreementsbetween the physical behaviors of the theoretical simulations and the measurements wasachieved by which the validity of the model was verified. Using the results, the hydration andsoil migration in the entire maturation process were presented in diagram. The model was alsoused for preliminary evaluation of the maturation products in real boreholes by assuming thesame Holmehus clay as used in the tests. Two constellation of borehole and dense clay withdifferent diameters, 80 cm borehole /60 cm clay and 80cm/50cm, were assumed. The resultsrespecting dry density and hydraulic conductivity of the ultimate maturation products, and thedegree of homogeneous of the buffer and backfill clay system in the assumed boreholes, arepresented and discussed. The options of different mineral types and initial physical propertiesof the candidate buffer clays provide a reference for engineering barrier design of HLW disposalin VDH.

  • 1397.
    Yang, Ting
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Xiaodong, Liu
    East China Institute of Technology, Fuzhou, Jiangxi.
    Swelling properties and permeability of expandable clays of potential use for nuclear waste disposal2016Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 6, nr 2, s. 49-61Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Bentonite clay has attracted considerable attention as isolating material for safe disposal of high-level radioactive nuclear waste (HLW) on account of its low hydraulic conductivity and high swelling capacity. In the presently described study, three candidate smectitic clay materials were investigated and compared with respect to hydraulic conductivity and expandability. The clay samples were prepared from desiccated and crushed raw material placed and compacted in oedometer cells for saturation with distilled water and 3.5% CaCl2 solution in separate test series to a density at fluid saturation of 1200 ~ 1900 kg/m3. The samples were tested with respect to the hydraulic conductivity and swelling capacity. The MX-80 and Homehus clays matured as expected giving a successively monotonous increase in swelling pressure during the wetting process while GMZ clay showed two pressure peaks. The pressure development was different for low and high densities and can be explained by crystal expansion via interlamellar wetting, followed by osmotic swelling including establishment of electrical double-layers. The phenomena can alternatively be explained by the microstructural changes when clay minerals absorb solutions in the hydration phase. Differences in granule size distributions and mineral composition can explain different swelling abilities and permeabilities.

  • 1398.
    Yang, Ting
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Liu, Xiaodong
    East China University of Technology.
    Assessment of clay buffers for isolating HLW2014Inngår i: Waste Management and The Environment VII / [ed] C.A. Brebbia; G. Passerini; H. Itoh, Southampton: WIT Press, 2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Great effort is put on finding optimal buffer clays for isolating highly radioactive waste (HLW) in countries utilizing nuclear energy. Different materials are required to provide a hydrologically and mechanically suitable surrounding of canisters with highly radioactive waste in repositories in crystalline rock. For shallow disposal the high hydraulic conductivity of the rock makes very dense smectite-rich clays necessary while for disposal in very deep holes the primary desire is to use smectitic clays with a potential to resist high temperatures. In both cases montmorillonite, with Al being a dominant lattice ion in the octahedral layer, is suitable, but saponite with Mg as dominant octahedral constituent can be preferable for deep disposal. For both concepts use of smectitic mud is an option for supplying the buffer with water from start and for controlling the hydration rate.

  • 1399.
    Yang, Ting
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Liu, Xiaodong
    East China University of Technology.
    Lab testing of method for clay isolation of spent reactor fuel in very deep boreholes2015Inngår i: Vol. 15, s. 152-158Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In Sweden and Finland and some other countries, two basically different multibarrier concepts for disposal of spent reactor fuel (HLW) are the often cited KBS-3 methods and Very Deep Boreholes methods (VDH), on which the paper focuses. These concepts have engineered barriers in the form of clay-embedded canisters with spent reactor fuel.. The clay, placed around the canisters and between them, provides ductility and tightness for minimizing the risk of canister breakage, and for tightness. The large-diameter VDH holes have dense clay seals of smectite-rich material in combination with clay mud for stabilization of the rock. In this paper, clay mud of smectite-rich Danish Holmehus clay was investigated for evaluating the physical interaction with the dense clay blocks. The possibility of solving the problem of too quick hydration of the blocks, which can make the resistance to insertion of the units of dense clay and canisters (“supercontainers”) in the mud difficult, was investigated by using prewetted dense clay blocks prepared by a new method (“DW” technique). The laboratory experiments, which were made to simulate the installation of supercontainers in clay mud using model versions of them, have given promising results.

  • 1400.
    Yao, Yu
    Luleå tekniska universitet.
    A laboratory study of mechanical characteristics of a marine soil1987Rapport (Annet vitenskapelig)
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