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  • 1.
    Bodare, Anders
    et al.
    Geo Risk & Vibration Scandinavia.
    Massarsch, Rainer
    Geo Risk & Vibration Scandinavia.
    Wersäll, Carl
    Geo Risk & Vibration Scandinavia.
    Planning and Execution of Rock Blasting in Urban Areas2009In: Environmental Vibrations: Prediction, Monitoring, Mitigation and Evaluation / [ed] H. Xia & H. Takemiya, 2009, p. 784-789Conference paper (Refereed)
    Abstract [en]

    Proper management of technical risks during blasting facilitates efficient project management and helps keeping costs and safety at an acceptable level. it is of crucial importance to incorporate the process of risk management in the design and execution of the project. Risk analyses of the environmental effect of blast-induced vibrations are, in many cases, based on crude concepts which do not take into consideration the fundamental nature of vibratory motion. Realistic modeling of wave propagation in soil and rock requires that correct dynamic parameters are considered and appropriate attenuation models are applied. It is possible to apply relatively simple vibration attenuation concepts for prediction of vibrations in soil and rock and their interaction with structures on or below the ground surface.

  • 2.
    Hov, Sölve
    et al.
    Geomind AB.
    Eriksson, Håkan
    Geomind AB.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Dynamic Compaction of Rockfill on Land and under Water at Stockholm Norvik Port2018Conference paper (Refereed)
  • 3.
    Larsson, Stefan
    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.
    Spross, Johan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Geotekniker och bergmekaniker ska lära för livet: men hur ska det gå till?2014In: Bygg & teknik, ISSN 0281-658X, no 1, p. 70-72Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Geoteknikeroch bergmekaniker ska ha förmågan att projektera, bygga och underhålla geokonstruktionerför det moderna samhället. Konstruktionerna måste vara både ekonomiska, säkra,estetiska och miljövänliga. Ingenjören får sin kompetens genom utbildning,träning och erfarenheter från skolan, annan fortbildning och arbete iprojekten. Kraven på en bred kunskapsbas ökar alltmer, samtidigt som det krävsen betydande fördjupning inom det specifika ämnesområdet. Både högskolorna ochnäringslivet genomgår nu ett påtagligt generationsskifte och det är därförlämpligt att inom de närmaste åren utföra en omfattande didaktisk analysavseende: Vad ska läras ut? Varför ska det läras ut? Hur ska det läras ut? Förvem ska det läras ut? Vi anser att geoteknik­ och bergmekanikundervisningen börinriktas på att ge ingenjören förmågor som ska utgöra en bas för ett livslångtlärande.

  • 4.
    Massarsch, K. R.
    et al.
    Geo Risk & Vibrat Scandinavia AB, Stockholm, Sweden..
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Monitoring and Process Control of Vibratory Driving2019In: Geotechnical Engineering, ISSN 0046-5828, Vol. 50, no 3, p. 1-10Article in journal (Refereed)
    Abstract [en]

    Vibrators are used increasingly in the foundation industry, primarily for installation of piles and sheet piles, but also for deep vibratory compaction. Fundamentals of vibratory driving are described that make it possible to choose vibrator performance parameters based on field monitoring and performance control. Variable frequency and amplitude vibrators have become available that make it possible to adapt the driving process to project-specific requirements. The components of modern electronic measuring systems are detailed that can be used to monitor, control, and document different aspects of vibratory driving. Two examples are presented-vibratory driving of sheet piles and resonance compaction-which show how the performance of vibrators and sheet piles can be analysed and adapted to meet specific requirements. By using the advanced monitoring and process control systems, the efficiency of vibratory driving is enhanced. From the retrieved parameters, a better understanding of the vibratory driving process is gained, which can be used to develop a valuable database.

  • 5. Massarsch, K. Rainer
    et al.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Acoustic soil and rock sounding2017Conference paper (Refereed)
  • 6.
    Massarsch, K. Rainer
    et al.
    Geo Risk and Vibration Scandinavia AB, Ferievägen 25, SE-168 41 Bromma, Sweden .
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Cumulative lateral soil displacement due to pile driving in soft clay2013In: SOUND GEOTECHNICAL RESEARCH TO PRACTICE: HONORING ROBERT D.HOLTZ II, 2013, no 230, p. 463-480Conference paper (Refereed)
    Abstract [en]

    Installation of preformed piles in clay causes lateral displacements of soil and of foundations of nearby structures embedded in the ground. The problem has been assessed by first analyzing the displacement effects of a single pile based on model tests and numerical analyses. Lateral soil displacement can be predicted using cavity expansion theory. Model tests were performed to study lateral displacements of soil due to installation of a group of piles. The results of theoretical analyses and model tests were compared with field measurements. A method is proposed to estimate cumulative lateral soil displacements caused by the installation of a pile group. The effect of sloping ground on lateral soil movements is addressed. Prediction of lateral soil displacement due to installation of several rows of piles in clay is illustrated by a practical example.

  • 7.
    Massarsch, Rainer
    et al.
    Geo Risk & Vibration AB.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Horisontell jordundanträngning vid pålslagning i lera2014In: Bygg & teknik, ISSN 0281-658X, no 1, p. 46-51Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    I Sverige slås årligen ett stort antal prefabricerade pålar som kan påverka omgivningen påtagligt i form av vibrationer och markrörelser. Redan slagna pålar kan utsättas för horisontalrörelser då resterande pålar i pålgruppen installeras. Pålkommissionens Rapport 95 ”Omgivningspåverkan vid pål- och spontslagning” beskriver en beräkningsmetod som bygger på empiriska tumregler, men som saknar vetenskaplig förankring.

    Nyligen avslutades ett SBUF-projekt ”Massundanträngning i samband med pålslagning i lera” där resultat från fältmätningar jämfördes med olika beräkningsmetoder. I projektet visades, med stöd av fältmätningar, att beräkningsmetoden enligt Pålkomissionens rapport inte kan förutsäga den horisontella jordförskjutningen på ett tillfredsställande sätt. Istället rekommenderas avancerade beräkningsmetoder, såsom FEM. I föreliggande artikel beskrivs hur jordens horisontalförskjutning kan uppskattas med en enkel beräkningsmodell vid plan eller lutande markyta. Även åtgärder för att minska jordundanträngningen, såsom lerproppdragning, diskuteras.

  • 8.
    Massarsch, Rainer
    et al.
    Geo Risk & Vibration Scandinavia.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Vibrationspåverkan från tågtrafik på pålgrundlagd byggnad2017In: Bygg & teknik, no 1, p. 15-20Article in journal (Other (popular science, discussion, etc.))
  • 9. Massarsch, Rainer
    et al.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Vibratory plate resonance compaction2018In: Proceedings of the Anniversary Symposium – 40 Years of Roller Integrated Continuous Compaction Control (CCC), 2018Conference paper (Refereed)
  • 10.
    Nejad Ghafar, Ali
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Mentesidis, Anastasios
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Draganovic, Almir
    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.
    Ett nytt sätt att förbättra inträngnigs egenskaperna hos cementbaserat injekteringsbruk med momentant varierande tryck2016In: Bygg & teknik, ISSN 0281-658X, no 1, p. 17-22Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Ett mycket viktig moment i samband med undermarksbyggande är tätning av konstruktioner för att hindra vatteninflöde eller ett eventuellt läckage av lagrade material i konstruktionen. Sedan mitten på 1980-talet har man på Kungliga tekniska högskolan (KTH) forskat kring injekteringen av sprickor i berg med varierande tryck för att förbättra inträngningsförmågan av cementbaserade bruk. I tidigare studier har man huvudsakligen undersökt effekten av högfrekventa oscillerande tryck på brukets inträngningsförmåga men den uppnådda förbättringen har visat sig vara relativt begränsad. I ett doktorandprojekt på KTH har vi genomfört en experimentell studie för att undersöka påverkan av istället ett lågfrekvent tryck med en momentan tryckförändering på brukets inträngningsförmåga. Resultaten har visat på en betydande förbättring av inträngningsförmågan hos bruket jämfört med injektering med konstant tryck. Projektet har finansierats av Stiftelsen Bergteknisk Forskning (BeFo), Svenska Byggbranschens Utvecklingsfond (SBUF) och Trafikverket.

  • 11.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Frequency Optimization of Vibratory Rollers and Plates for Compaction of Granular Soil2016Doctoral thesis, comprehensive summary (Other academic)
    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.

  • 12.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Influence of Frequency on Compaction of Sand in Small-Scale Tests2013Licentiate thesis, comprehensive summary (Other academic)
    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.

  • 13.
    Wersäll, Carl
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Optimering av packningsparametrar för vibrationsvältar2015Conference paper (Other academic)
    Abstract [sv]

    Jordpackning av bankar och fyllning utförs normalt med vibrationsvält i olika typer av anläggningsprojekt. I ett doktorandprojekt vid KTH studeras hur denna process kan effektiviseras genom att optimera vissa packningsparametrar. Huvuddelen av projektet syftar till att finna den optimala vibrationsfrekvensen. Omfattande småskaleförsök har utförts i laboratorium som visar att frekvensen har stort inflytande över packningseffektiviteten. Fullskaleförsök kommer att visa om och hur dessa resultat kan implementeras i praktiken. Inom projektet har även en beräkningsmodell utvecklats som enkelt kan förutsäga den dynamiska responsen av en vibrerande platta på markytan. Projektet finansieras av Svenska Byggbranschens Utvecklingsfond (SBUF), Dynapac Compaction Equipment AB, Trafikverket, PEAB och Fredrik Bachmans minnesfond.

  • 14.
    Wersäll, Carl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Bodare, Anders
    Geo Risk & Vibration Scandinavia.
    Massarsch, Rainer
    Geo Risk & Vibration Scandinavia.
    Frequency content of vertical ground vibrations caused by surface impact2012Conference paper (Refereed)
  • 15.
    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 Tracks2012In: Noise and Vibration Mitigation for Rail Transportation Systems / [ed] T. Maeda et al., Berlin: Springer, 2012, p. 267-274Chapter in book (Refereed)
    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.

  • 16.
    Wersäll, Carl
    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.
    Influence of force ratio and frequency on vibratory surface compaction2016In: Geotechnics for Sustainable Infrastructure Development / [ed] Phung Duc Long, 2016Conference paper (Refereed)
  • 17.
    Wersäll, Carl
    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.
    Small-Scale Testing of Frequency-Dependent Compaction of Sand Using a Vertically Vibrating Plate2013In: ASTM geotechnical testing journal, ISSN 0149-6115, E-ISSN 1945-7545, Vol. 36, no 3, p. 394-403Article in journal (Refereed)
    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.

  • 18.
    Wersäll, Carl
    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.
    Bodare, Anders
    Dynamic response of vertically oscillating foundations at large strain2014In: 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, p. 643-647Conference paper (Refereed)
    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.

  • 19.
    Wersäll, Carl
    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.
    Rydén, Nils
    Lund Universitet.
    Nordfelt, Ingmar
    Dynapac.
    Frequency Variable Surface Compaction of Sand Using Rotating Mass Oscillators2015In: ASTM geotechnical testing journal, ISSN 0149-6115, E-ISSN 1945-7545, Vol. 38, no 2, p. 198-207Article in journal (Refereed)
    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.

  • 20.
    Wersäll, Carl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Massarsch, Rainer
    Geo Risk and Vibration Scandinavia AB.
    Soil Heave Due to Pile Driving in Clay2013In: 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, p. 481-499Conference paper (Refereed)
    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.

  • 21.
    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 Tunnels2009In: Environmental Vibrations: Prediction, Monitoring, Mitigation and Evaluation, VOLS I AND II / [ed] H. Xia & H. Takemiya, 2009, p. 749-756Conference paper (Refereed)
    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.

  • 22.
    Wersäll, Carl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Nordfelt, I.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Resonant roller compaction of gravel in full-scale tests2018In: Transportation Geotechnics, ISSN 2214-3912, Vol. 14, p. 93-97Article in journal (Refereed)
    Abstract [en]

    Results from a recent study indicated that compaction by vibratory roller can be made more time- and energy-efficient by operating at a vibration frequency close to resonance. In this paper, the results are verified and the reduction in operating time is quantified by conducting detailed full-scale tests under realistic conditions at two frequencies: the standard operating frequency of the roller and a lower frequency slightly above resonance. Compaction was done in two tests per frequency with 16 passes in each test. The obtained compaction was quantified using a combination of measurement techniques, including laser levelling, nuclear density gauge and static plate load tests. The results confirm that the lower frequency is more efficient for compaction and that utilizing resonance in the roller-soil system can reduce the number of passes. In addition, lowering the frequency reduces energy consumption, environmental impact and machine wear. 

  • 23.
    Wersäll, Carl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Nordfelt, Ingemar
    Dynapac.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Vibrovältar och jorddynamik - mot effektivare packning2013In: Bygg & teknik, ISSN 0281-658X, no 1, p. 32-35Article in journal (Other (popular science, discussion, etc.))
    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.

  • 24.
    Wersäll, Carl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Nordfelt, Ingmar
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Effektivare packning med nya insikter2018In: Bygg & Teknik, ISSN 0281-658X, no 1, p. 44-45Article in journal (Other academic)
  • 25.
    Wersäll, Carl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Nordfelt, Ingmar
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Roller compaction of rock-fill with automatic frequency control2018In: Proceedings of the Anniversary Symposium – 40 Years of Roller Integrated Continuous Compaction Control (CCC), 2018Conference paper (Refereed)
  • 26.
    Wersäll, Carl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Nordfelt, Ingmar
    Dynapac Compaction Equipment AB.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Soil compaction by vibratory roller with variable frequency2016In: Geotechnique, ISSN 0016-8505, E-ISSN 1751-7656Article in journal (Refereed)
    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.

  • 27.
    Wersäll, Carl
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Åkesson, Fredrik
    Persson, Andreas
    Dynamic roller characteristics and CCC using automatic frequency control2019Conference paper (Refereed)
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