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  • 1351.
    Svedberg, Bo
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mácsik, Josef
    LTU.
    Knutsson, Sven
    Modell för miljögeoteknisk bedömning av väg- och järnvägsbyggnadsmaterial: ämnestransport i mark - omgivning2003Rapport (Annet vitenskapelig)
    Abstract [sv]

    Denna rapport "Ämnestransport i mark, Omgivning" utgör en del i ett projekt med namnet "Modell för miljögeoteknisk bedömning av väg- och järnvägsbyggnadsmaterial" förkortat MGB. Projektet MGB syftar till att ta fram en enhetlig bedömningsmodell för att möjliggöra en samlad bedömning av Användningsaspekter (själva ban- och vägkonstruktionen) och Omgivningsaspekter (omgivande områden) i samband med materialval för vägar och järnvägar. Målsättningen är att modellen ska vara repeterbar och enkel att tillämpa vid materialval och vara oberoende av materialets ursprung. I rapporten har en rad olika aspekter som identifierats vid ett materialval för en ban- eller vägkonstruktion grupperats i två huvudgrupper, Omgivnings- respektive Användningsaspekter. Exempel på aspekter är hydrogeologi, geoteknik, miljöteknik. Inom varje aspekt finns det parametrar som bland annat beskriver förutsättningar för ämnestransport, som till exempel hydraulisk konduktivitet, kornstorleksfördelning och pH. Syftet med denna rapport är att ge en förståelse för hur omgivningens (markens) tekniska och kemiska egenskaper påverkar ämnestransport från en ban- och vägkonstruktion. Utgångspunkten för arbetet är att man med rimlig noggrannhet ska kunna beskriva ämnestransporten i mark. Detta låter sig t ex göras genom att beskriva de styrande parametrarna och med dessa som underlag bedöma förutsättningarna för spridningen från ett objekt. Med bedömningen av ämnestransport som grund, kan sedan en bedömning göras av effekter och konsekvenser på människors hälsa och miljön i stort. Spridning av ämnen från en väg- och bankropp till omgivningen kan ske på olika sätt. Det vanligaste spridningssättet för olika ämnen och substanser är spridning i löst form i vatten, men det finns också andra transportsätt, t ex avgång i gasfas (lättflyktiga ämnen) eller i fast fas med vatten eller luft (partiklar). Parametrar som nedbrytning, fastläggning, utspädning etc medverkar också till att styra omfattningen av ett ämnes spridning kring en väg- eller bankonstruktion. Styrande parametrar Med bakgrund av den kunskap som inhämtats om valda aspekter och tillhörande parametrar har olika typer av ban- eller vägsträckningar studerats översiktligt. I exemplen, som avsett en sträckning genom skogsmark på undergrund av morän respektive en sträckning genom lövskog på undergrund av lera och berg, sammanställdes olika aspekter med deras tillhörande parametrar i tabellform för att beskriva förutsättningarna för bedömning av ämnestransport. Det framgår av arbetet att det finns några huvudfrågeställningar med avseende på transport av ämnen i den mättade zonen som måste vara uppfyllda för att ämnen överhuvudtaget ska transporteras i någon nämnvärd omfattning, till dessa hör att:- Det finns en källa- Det finns vatten som kan lösa och transportera ämnet- Marken kan transportera vatten i nämnvärd omfattning Dessa frågeställningar är primärt relaterade till aspekterna hydrologi och hydrogeologi samt jordartsgeologi. Finns det förutsättningar för transport är det sedan andra aspekter som styr om ämnet uppbromsas (retarderas) på något sätt. Detta kan till exempel ske genom fastläggning, nedbrytning eller omvandling. Den kanske viktigaste är sorption eller fastläggning som dels styrs av jordens kornstorleksfördelning och dels av markkemiska förutsättningar. Många av de parametrar som erfordras för en bedömning av förutsättningar för ämnestransport finns redan idag att tillgå i den byggprocess som tillämpas av Banverket och Vägverket. T ex ingår i tidiga skeden att inhämta kunskap om ett områdes geotekniska förutsättningar. Ur detta kan man inhämta kunskap om olika parametrar som grundvattennivå, jordlagerföljd m fl. Å andra sidan finns det andra parametrar som inte inhämtas idag, i vart fall inte regelmässigt. Till dessa hör t ex olika markkemiska parametrar som beskriver den intilliggande omgivningen.

  • 1352.
    Svedholm, Christoffer
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad. ELU Konsult AB, Stockholm, Sweden.
    Pacoste-Calmanovici, Contin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad. ELU Konsult AB, Stockholm, Sweden.
    Karoumi, Raid
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Bro- och stålbyggnad.
    Modal properties of simply supported railway bridges due to soil-structure interaction2015Inngår i: COMPDYN 2015, 2015, s. 1709-1719Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Resonance vibration of railway bridges has become an important design issue during the last decade due to the development of new high-speed lines. At resonance it is well known that the damping of the structure has a great influence on the final response. The current paper presents modal parameters, such as modal damping ratios and natural frequencies, derived based on a simply supported Bernoulli-Euler beam on an elastic half-space. In the current chapters of Eurocode dealing with dynamical analysis of railway bridges, the expression for the modal damping ratio is essentially empirical. The novelty of this paper is therefore two-fold: (1) provide modal damping ratios for soil-structure interaction, and (2) show that the damping should not be considered as constant for all modes but it varies depending on the particular mode shape and interaction with the soil.

  • 1353.
    Söderlund, Olov
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser.
    Stabilization of Soft Soil with Lime and PetritT-An Experimental Study2018Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
  • 1354.
    Söderström, Patrik
    et al.
    ATCON AB.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Olofsson, Thomas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Edeskär, Tommy
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mårtensson, Stefan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Zeinali, Amin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Snow grooming using machine guidance for piste management processes: Case study: Ormberget ski piste2013Rapport (Annet vitenskapelig)
    Abstract [en]

    The snow is an increasingly precious commodity to the ski industry's production of pistes. To preserve this commodity is the basis for economic production. The wear on the groomed snow consists primarily of two reasons: skiers and melting. A slope that is optimally processed will last longer and require less maintenance. In addition to this obvious that maintenance must be planned based on where wear has taken place there is an additional planning variable, namely time. Timing is of utmost importance when it comes to snow as a material. A process model will be presented covering a systematic approaches how road construction technologies can be adapted to the snow grooming process. The expected results are a process model which can be used in order to optimize the snow grooming management in order to extend the skiing season. There is possibly two ways of doing this. Firstly to optimize the snow mass haul management process during the skiing season. Secondly re-build the different piste off season to create better environmental conditions during season. This study consists of four kinds of data. Laser scanned data for 3D terrain modeling of ski piste (ground) and collected data by snow groomer for 3D terrain modeling of ski piste during the objective period of investigation. The differences between 3D terrain models by laser scanning and snow groomer is representative of snow depth for corresponding day. Furthermore, in order to verify the method, snow depth and snow surface are measured by group of students from Luleå University of Technology.

  • 1355.
    Sölve, Hov
    et al.
    GeoMind.
    Persson, Erik
    Bjerking.
    Prästings, Anders
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Larsson, Stefan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Korrelationer mellan odräneradskjuvhållfasthet och förkonsolideringstryck i lera2018Inngår i: Bygg & teknik, ISSN 0281-658X, nr 1, s. 55-58Artikkel i tidsskrift (Annet vitenskapelig)
  • 1356.
    Taeseri, D
    et al.
    Department of Civil Engineering, ETH Zurich, Zurich, Switzerland.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Otsubo, M
    Department of Civil Engineering, University of Tokyo, Tokyo, Japan.
    Towhata, I
    Department of Civil Engineering, University of Tokyo, Tokyo, Japan.
    New mitigation method for pipeline uplift during seismic event2016Inngår i: Geotechnical Research, E-ISSN 2052-6156, Vol. 3, nr 2, s. 54-64Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Tohoku earthquake in 2011 caused several damages to the pipeline network in the Tokyo Bay area. Predominantly, the main damages were noticed in the artificial islands, where liquefaction destroyed and deformed numerous embedded pipelines. During a seismic event, lifeline systems are subjected to buoyancy forces in the liquefied soil, causing permanent deformations to pipelines and interrupting their serviceability. The current mitigation methods (backfill improvement) are not suitable for regions prone to future earthquakes because pipe excavation and improvement is time-consuming and costly. Therefore, the aim of this study is to present a new effective mitigation method: the so-called horn-type structure. This innovative mitigation method was analysed with different analytical, experimental and numerical methods.

  • 1357.
    Taeseri, Damoun
    et al.
    Institute for Geotechnical Engineering, ETH Zurich, Switzerland.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Martakis, P.
    ETH Zurich, Switzerland.
    Chatzi, Eleni
    Institute of Structural Engineering, ETH Zurich, Switzerland.
    Anastasopoulos, Iannis
    Institute for Geotechnical Engineering, ETH Zurich, Switzerland.
    Static and dynamic rocking stiffness of shallow footings on sand: centrifuge modelling2018Inngår i: International Journal of Physical Modelling in Geotechnics, ISSN 1346-213X, Vol. 18, nr 5, s. 315-339Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Small-strain foundation response has mostly been studied analytically, with limited experimental verification against 1g physical model tests. This paper revisits the problem of small-strain foundation response, conducting a series of centrifuge model tests, aiming to eliminate the limitations of 1g testing. A centrifuge modelling technique is developed, combining static pushover and dynamic impulse testing for similar systems. To allow for derivation of meaningful insights, a novel procedure for in-flight measurement of the distribution of shear modulus with depth is also developed. The latter combines spectral analysis of surface waves (SASW) measurement of the shear modulus G0 at the surface, and estimation of the distribution of the shear modulus G with depth using acceleration measurements in shaking tests. A novel centrifuge tube-actuator is developed and employed to discharge spherical projectiles against single-degree-of-freedom models lying on shallow foundations on sand. This allows generating dynamic impulse excitation, which is used to measure the small-strain dynamic rocking stiffness. The developed actuator is versatile, and was also used for in-flight SASW testing. The centrifuge model tests are shown to confirm the widely used and well-known formulas. This good agreement can also be seen as a confirmation of the validity of the developed experimental techniques. 

  • 1358.
    Taeseri, Damoun
    et al.
    ETH Zurich.
    Martakis, Panagiotis
    ETH Zurich.
    Chatzi, Eleni
    ETH Zurich.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    A centrifuge: experimental study in the soil and structure interaction effect on a SDOF systemMendeleyCSVRISBibTeX2016Inngår i: Eurofuge 2016: 3rd European Conference on Physical Modelling in Geotechnics, Nantes, France, June 1-3, 2016, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Soil Structure Interaction (SSI) refers to structural elements in contact with soil and implies the response of the system to an external loading. Up to now, the importance of this effect is not thoroughly taken into account in the design codes. In praxis, geotechnical engineers tend to replace the foundation with a stiff inclusion while structural engineers assume springs or fixed boundary conditions in simulating foundations. In this work, a set of centrifuge experiments are conducted in order to highlight the influence of specific soil and structural parameters within the context of the SSI effect. The chosen model represents a SDOF system founded on homogenous soil. The main purpose of this experimental and analytical work is to examine the influence of the slenderness ratio between structure and soil to the magnitude of the SSI effects. These effects are quantified through the commonly adopted index of Period Lengthening Ratio (PLR). A centrifuge – experimental study in the soil and structure interaction effect on a SDOF system

  • 1359.
    Taeseri, Damoun
    et al.
    ETH Zurich.
    Otsubo, Masahide
    Imperial College London.
    Laue, Jan
    ETH Zurich.
    Towhata, Ikuo
    University of Tokyo.
    New mitigation method for pipelines under the effect of buoyancy forces during seismic events2015Inngår i: Geotechnical engineering for infrastructure and development: proceedings of the XVI European Conference on Soil Mechanics and Geotechnical Engineering / [ed] M.G. Winter, London: Research Publishing Services, 2015, Vol. 4, s. 2213-2218Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Lifeline systems in liquefiable soils are subjected to buoyancy forces during seismic events, causing permanent deformations to pipelines and interrupting their service (e.g. water supply, sewerage, etc.) for extended periods of time. For example, the Great East Earthquake and the Niigata Chuetsu Earthquake (Mimura et al. 2011) caused significant damage through floating of underground lifelines. Different mitigation methods, such as soil compaction, cement mixing or continuous structural measures, are currently used to reduce the liquefaction potential of the fill material. However, these methods are expensive and time consuming when considering the size of the lifelines' networks. This paper studies the "horn-type-structure" as a mitigation method, which is less expensive, more effective and faster to build for existing lifelines. One of the advantages of this method is that the horn-type-structure can be installed in strategic locations across the lifeline network only, thus reducing the overall amount of soil excavation along the entire network. Small scale experiments were conducted at the University of Tokyo and centrifuge tests were conducted at ETH-Zurich, aiming to understand the mechanism better and to develop a calculation method.

  • 1360.
    Taghizadeh Vahed, Amir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Enhanced K-Nearest Neighbors Method Application inCase of Draglines Reliability Analysis2018Inngår i: Proceeding of MPES - SWEMP 2018 / [ed] R. Singhal, E. Widzyk-Capehart, A. Hekmat, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Dragline’s availability plays a major role in sustaining economicfeasibility and operation of opencast coal mine. Thus, its reliability is essentialfor the production availability of mine. The dragline’s reliability and maintenanceoptimization are key issues, which should seriously be considered. Draglines’unexpected failures and consequently unavailability result in delayed productionsand increased maintenance and operating costs. The applications ofmethodologies which can predict the failure mode of dragline based on thehistorical dataset of failure are not only useful to reduce the maintenance andoperating costs but also increase the availability and the production rate of miningmachineries. In this research a historical failure dataset of a dragline has beenutilized in order to analyze and conduct predictive maintenance. Authors havealready utilized the K-Nearest Neighbors (KNN) algorithm in order to predict thefailure mode; however, there was a chance of getting into local optimum byutilization of the mentioned methodology. In this case, combination of GeneticAlgorithm and K-Nearest Neighbor algorithm (i.e. called enhanced K-NearestNeighbors) was applied for the failure dataset, so the probability of localoptimum has been decreased by application of Genetic Algorithm. In previousstudies, the Artificial Neural Network methods and conventional method of KNearestNeighbor has been applied to the same dataset, yet the result fromenhanced K-Nearest Neighbor reveals better regression analysis.

  • 1361.
    Tajbakhsh, Mohammad
    et al.
    Regional Water AuthorityKermanshahIran.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Comparative study of multi-station method and Hershfield’s approaches for PMP determination (case study: Northeast of Iran)2018Inngår i: Sustainable Water Resources Management, ISSN 2363-5037Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The maximum daily rainfall values for 36 homogeneous stations in the northeast of Iran were adopted to estimate the appropriate Probable annual Maximum Precipitation 1-day precipitation (PMP24) values. PMP24 was found as 128.2–284.2, 62.7–160.2 and 124 mm for Hershfield 1, Hershfield 2 and multi-station approach, respectively. The ratio of PMP24 to the highest observed 1-day rainfall was consistent for the second approach of Hershfield. It was in harmony with the multi-station method, but varied widely for Hershfield 1. This may be the result of different record length effect on Hershfield 1 approach. Finally, the map of PMP24 isochrones was prepared for the second approach of Hershfield for over northeast of Iran.

  • 1362.
    Tajbakhsh, Mohammad
    et al.
    Regional Water Authority, Zan Blvd., Kermanshah, Iran.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Comparative study of multi-station method and Hershfield’sapproaches for PMP determination: (case study: Northeast of Iran)2018Inngår i: Sustainable Water Resources Management, ISSN 2363-5037Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The maximum daily rainfall values for 36 homogeneous stations in the northeast of Iran were adopted to estimate the appropriate Probable annual Maximum Precipitation 1-day precipitation (PMP 24) values. PMP24 was found as 128.2–284.2, 62.7–160.2 and 124 mm for Hershfield 1, Hershfield 2 and multi-station approach, respectively. The ratio of PMP 24

    to the highest observed 1-day rainfall was consistent for the second approach of Hershfield. It was in harmony with the multi-station method, but varied widely for Hershfield 1. This may be the result of different record length effect on Hershfield 1 approach. Finally, the map of PMP 24 isochrones was prepared for the second approach of Hershfield for over northeast of Iran.

  • 1363.
    Tengelin, Elin
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Byggnadsteknik.
    Vetterlund-Handberg, Martina
    Högskolan i Jönköping, Tekniska Högskolan, JTH, Byggnadsteknik.
    ÅTERANVÄNDNING AV SCHAKTMASSOR2018Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syfte: Återanvändningen av schaktmassor inom anläggningsbranschen är i dagsläget begränsad. Bland annat på grund av otydliga regelverk samt låga kostnader och hög tillgänglighet av jungfruliga material. Trots att schaktmassor har en hög potential att återanvändas finns det andra alternativ för överskottsmassor som uppstår i ett projekt som är mer fördelaktiga för entreprenörer. Svårigheterna kring återanvändning av schaktmassor är det som skall undersökas och målet med rapporten är följaktligen att undersöka möjligheterna att främja återanvändning av schaktmassor inom anläggningsbranschen. Målet kommer att besvaras med hjälp av två frågeställningar: (1) Hur kan återanvändningen av schaktmassor främjas inom anläggningsbranschen? (2) Hur kan en återanvändningsterminal öka återanvändningen av schaktmassor?

    Metod: Metoderna som valts för att samla empiri till studien är litteraturstudie, dokumentanalys och intervjuer. Litteraturstudien och dokumentanalysen skapade en kunskapsuppbyggnad inom ämnet som bland annat låg till grund för utformningen av intervjuerna. Intervjuerna har genomförts tillsammans med tio respondenter från åtta olika företag inom anläggningsbranschen.

    Resultat: De regelverk och lagar som finns kring hanteringen av schaktmassor ses som det största hindret för återanvändningsmöjligheterna. Svårigheterna att få ekonomisk vinst i återanvändningsprocessen samt långa transporter är också bidragande orsaker. Även de geotekniska egenskaperna på schaktmassornas kan vara problematiskt, dels för att massorna skall klassificeras enligt sin byggbarhet samt att de skall vara jämförbara med jungfruligt material.

    Konsekvenser: Slutsatserna som dragits utifrån studien är att det krävs ett ökat samarbete inom branschen för att återanvändningen av schaktmassor skall främjas. Tydligare kommunikation behövs samt att planering kring masshanteringen bör ske i ett tidigare skeden i projekten. De regelverk och riktlinjer som finns idag behöver omarbetas för att bli tydligare och möjliggöra för ökad återanvändning. En återanvändningsterminal av storskalig verksamhet som placeras centralt skulle bidra till att återanvändningen av schaktmassor ökar vilket minskar miljöpåverkan och gynnar branschen.

    Begränsningar: Studien är begränsad och utförd inom Jönköpings län och intervjurespondenterna är valda utefter de verksamheter som verkar inom länet. Arbetets generaliserbarhet begränsar sig till Sverige eftersom att regelverk och tillvägagångssätt gällande hantering av schaktmassor ser olika ut i andra länder.

    Nyckelord: Utgrävd mark, återanvändning av schaktmassor, återanvändningsterminal, återanvändning av bergmaterial.

  • 1364.
    Tenzer, Robert
    et al.
    The Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
    Foroughi, Ismael
    Department of Geodesy and Geomatics, University of New Brunswick, Canada.
    Sjöberg, Lars E.
    Division of Geodesy and Satellite Positioning, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Bagherbandi, Mohammad
    Högskolan i Gävle, Akademin för teknik och miljö, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, Samhällsbyggnad, GIS. Division of Geodesy and Satellite Positioning, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Hirt, Christian
    Institute for Astronomical and Physical Geodesy and Institute for Advanced Study, Munich, Germany.
    Pitoňák, Martin
    New Technologies for the Information Society (NTIS), Faculty of Applied Sciences, University of West Bohemia, 301, Czech Republic.
    Definition of Physical Height Systems for Telluric Planets and Moons2018Inngår i: Surveys in geophysics, ISSN 0169-3298, E-ISSN 1573-0956, Vol. 39, nr 3, s. 313-335Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    In planetary sciences, the geodetic (geometric) heights defined with respect to the reference surface (the sphere or the ellipsoid) or with respect to the center of the planet/moon are typically used for mapping topographic surface, compilation of global topographic models, detailed mapping of potential landing sites, and other space science and engineering purposes. Nevertheless, certain applications, such as studies of gravity-driven mass movements, require the physical heights to be defined with respect to the equipotential surface. Taking the analogy with terrestrial height systems, the realization of height systems for telluric planets and moons could be done by means of defining the orthometric and geoidal heights. In this case, however, the definition of the orthometric heights in principle differs. Whereas the terrestrial geoid is described as an equipotential surface that best approximates the mean sea level, such a definition for planets/moons is irrelevant in the absence of (liquid) global oceans. A more natural choice for planets and moons is to adopt the geoidal equipotential surface that closely approximates the geometric reference surface (the sphere or the ellipsoid). In this study, we address these aspects by proposing a more accurate approach for defining the orthometric heights for telluric planets and moons from available topographic and gravity models, while adopting the average crustal density in the absence of reliable crustal density models. In particular, we discuss a proper treatment of topographic masses in the context of gravimetric geoid determination. In numerical studies, we investigate differences between the geodetic and orthometric heights, represented by the geoidal heights, on Mercury, Venus, Mars, and Moon. Our results reveal that these differences are significant. The geoidal heights on Mercury vary from − 132 to 166 m. On Venus, the geoidal heights are between − 51 and 137 m with maxima on this planet at Atla Regio and Beta Regio. The largest geoid undulations between − 747 and 1685 m were found on Mars, with the extreme positive geoidal heights under Olympus Mons in Tharsis region. Large variations in the geoidal geometry are also confirmed on the Moon, with the geoidal heights ranging from − 298 to 461 m. For comparison, the terrestrial geoid undulations are mostly within ± 100 m. We also demonstrate that a commonly used method for computing the geoidal heights that disregards the differences between the gravity field outside and inside topographic masses yields relatively large errors. According to our estimates, these errors are − 0.3/+ 3.4 m for Mercury, 0.0/+ 13.3 m for Venus, − 1.4/+ 125.6 m for Mars, and − 5.6/+ 45.2 m for the Moon.

  • 1365. Tesarik, D.R.
    et al.
    Hustrulid, W.A.
    Nyberg, Ulf
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Assessment and application of a single-charge blast test at the Kiruna mine, Sweden2011Inngår i: Blasting and Fragmentation, ISSN 1937-6359, Vol. 5, nr 1, s. 47-72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [sv]

    Partikelhastighet (PPV) och avståndsmätningar utförda av svenska forskare presenteras för enskottsladdningar i järnmalm i Kiruna gruvan i norra Sverige. De används tillsammans med teoretiska PPV-värden som beräknats med hjälp av en formel baserad på hydrodynamik för att bestämma skadornas omfattning orsakas av en enda laddning. Denna ekvation, som relaterar PPV till explosiva egenskaper, laddningsgeometri och avstånd från en laddning, tillämpades sedan på en laddning av olika geometri som användes i ortdrivning. En jämförelse mellan beräknade och uppmätta PPV tyder på att strosshålen sannolikt skada läget för hjälparhålen, och att hjälparhålen ger skador där konturhålen sitter. Den praktiska konsekvensen är att typiska skadeberäkningar baserade på mätningar utförda i oskadat berg är konservativa. Detta tyder på att även när begränsningar av sprängskador inte tillämpas för drivning (dvs konturhålen är fulladdade), kan den resulterande skadan bli mindre än förväntat på grund av den vågdämpande effekten som det förspräckta berget utgör. På grund av den dämpande effekten, kommer dålig kontroll av kontursprängning att till vis del vara sälvkorrigerande. Det måste dock starkt betonas att väl en utvecklad utformning av sprängning med kontroll av konturen är mycket fördelaktig i förhållande till både ekonomiska och säkerhetsmässiga aspekter.

  • 1366.
    Thorbjörnson Lind, Thomas
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Rockfalls from rock cuts beside Swedish railroads: A full scale fieldtest, to investigate rockfalls and how rock bounces2016Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Rockfalls is a major problem around the world, if they occur in populated areas, they can cause major damage to infrastructure, injure or kill people. For this reason, it is important to be able to predict where the risk of rockfalls and how to prevent and protect populated areas from them. However, it is no easy task to predict rockfalls. Although if an area with potential area for rockfall is localized it may seem easy to construct protective meshing or bolting potential blocks down. But in many cases this is not easy to do due to practical issues or economic reasons, for example in rock cuts on older railways in Sweden. Fall heights from rock cuts like that are not particularly high but the risk of damage to the trains and infrastructure in the track area is high, however, it is unknown how extensive the damage may be. Trafikverket, the Swedish authority responsible for Sweden's roads and railways, has for some years investigated a new method for classifying and minimize the risk of rockfalls from rock cuts next to the railways. This study include aims to include the potential maximum distance of a block from the rockfall can travel to the existing method.

    This master's work is part of the investigation and will include full scale field test where the rockfalls are examined by filming them and then evaluate the “bounce coefficient”, coefficient of restitution, from the individual rockfalls using photogrammetric methods. During the field study, a geotechnical testing equipment, DCP test rig, to be evaluated for its ability of an easy way in the field to produce an estimated value on the coefficient of restitution. During the evaluation, two rockfall simulating software be used to investigate how well the results from them match the true blocks movements.

  • 1367.
    Toromanovic, Jasmina
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    On Parameter Identification for Better Predictions of Dam Behaviour2018Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Numerical modelling is often needed as a tool to predict the behaviour and assess the safety of dam structures. Embankment dam structures analyses are quite complex and potential failures are hazardous. Predictions of dam behaviour by numerical modelling rely on knowledge about the mechanical properties of the materials the dam is constructed with. The materials included in a dam vary significantly because zones in the dam have different functions. In order to conduct reliable modelling, parameter values defining the stress-strain relationship of the materials are needed to be assigned.

     Obtaining information about the mechanical behaviour in already existing embankment dams is usually challenging. As many dams are old, there might be a limited amount of information available of the materials used, construction methods and mostly about the stress-strain relationship of the soil. Traditionally, field sampling is performed in order to obtain such information. However, conventional field sampling might negatively affect the dam body and thereby the performance as well as the safety of the dam. This is of special importance if sampling is performed in the impervious (core) part. Since traditional sampling might harm the dam body, use of non-destructive methods would be advantageous to utilise for obtaining information about the stress-strain relationship and the strength in a dam structure.

     An option for a non-destructive method is parameter identification by inverse analysis. The idea of inverse analysis is to calibrate finite element models towards field measurements. In the calibration process, the input for a stress-strain relationship (constitutive model) is modified until the discrepancy between the output of the numerical model and the associated chosen field measurement is minimised. The agreement between output from the numerical model and reality is measured by an objective function that will calculate the error. In order to automatically search for the minimum a search algorithm is utilised in the optimisation process. When the objective function is minimised, the calibration of the material parameters is done.

     In previous research at Luleå University of Technology, the method of inverse analysis was applied to an embankment dam. The finite element program PLAXIS was used in combination with an optimisation code. The optimisation code includes an objective function (for error evaluation) and a search algorithm. The genetic algorithm was employed as search algorithm, since it is known for its robustness and efficiency as well as the fact that it provides a set of solutions instead of one unique answer. This is beneficial from a geotechnical point of view, since engineering judgement can be included in the final choice of solution.   

     The first study in the present thesis deals with a case study of an embankment dam, where a simple model calibration was performed. This was a part of a larger study, at the ICOLD Benchmark Workshop in 2017, where the work presented here was forming one of the contributions. In order to have a model response similar to reality, the contributors were asked to choose constitutive models and calibrate them. The calibration was done by manually changing the input for the constitutive model chosen. While the response of the numerical finite element model was capturing the trends of measured total stresses and pore pressure in the dam quite well, there were difficulties in capturing the long term deformations of the dam. This was a challenge for all contributors. An idea for improving the model response, is to run a more advanced calibration by inverse analysis.

     In the second study in the thesis, predictions are presented for the embankment dam that inverse analysis was previously conducted for at LTU. Strengthening actions in form of a new berm were performed at the dam. With identified material parameter values from the inverse analysis, predictions were conducted both before and after the strengthening measures. The predicted deformations were compared to deformation data from inclinometer measurements.  A reasonably well agreement was obtained with the real deformations. The trend of the deformations was replicated and the magnitudes of the deformations were in the right order. The study is indicating that predicting future dam behaviour based on results from inverse analysis can be done reasonably well.

     In the third and final study in the thesis, effects of random measurement error on the performance of the genetic algorithm for soil parameter identification are assessed. Also here, with the application to the embankment dam used in previous research at LTU. Optimisations were performed against inclinometer measurements. To be sure that the constitutive model can find the correct solution, synthetic (i.e. numerically generated) inclinometer data was utilised. Perturbations were randomly generated within chosen intervals of error and added to the numerically generated deformations.

     The genetic algorithm showed its robustness, by continuing to search for solutions without breaking down even if the field data was substantially perturbed. Considering usual errors for inclinometer measurements, the genetic algorithm can deliver good solutions. The inclinometer errors used were taken from literature, and thereafter related to the perturbations of the numerically generated data. Dealing with errors that are becoming gradually larger than what can be considered as usual, problems are faced by the genetic algorithm. In this cases it is difficult to find a solution, and if solutions are found they might significantly deviate from the unperturbed optimum solution.

     The three studies handled in this thesis are treating aspects of back analysis of embankment dams; from a simple calibration, to predictions based on material parameters from advanced inverse analysis and finally effects of errors on the genetic algorithm. It been shown that using inverse analysis for already existing embankment dams is very beneficial for the material characterisation and is forming a step towards better predictions of future dam behaviour.

  • 1368.
    Toromanovic, Jasmina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mattsson, Hans
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Utvärdering av dammars tillstånd2018Inngår i: SwedCOLD Nyhetsbrev, nr 2, s. 14-15Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 1369.
    Toromanovic, Jasmina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Assessment of Arching and Cracking Potential by Numerical Modelling: A Case Study of the Mornos Dam2017Konferansepaper (Fagfellevurdert)
  • 1370.
    Toromanovic, Jasmina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mattsson, Hans
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Use of parameters identified by inverse analysis in an earth- and rockfill dam application2017Inngår i: 85th Annual Meeting  of International Commission on Large Dams, 2017Konferansepaper (Fagfellevurdert)
  • 1371.
    Toromanovic, Jasmina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mattsson, Hans
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sipola, Johanna
    ÅF Hydropower Industry.
    Effects on an earth and rockfill dam undergoing dam safety measures2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Over the lifetime of a dam several measures are usually taken in order to assure the stability and the performance of the dam. In this case a hydropower dam in Northern Sweden is in need of dam safety measures. The question arose, what consequences there might be when such measures are performed. In order to estimate these effects, simulations have been carried out in the finite element programme PLAXIS 2D. Thereby, the deformations and the stability of the dam for the planned work can be evaluated. The performed simulations are based upon previously conducted research at Luleå University of Technology, where soil parameters in the investigated dam were identified by a method of inverse analysis.Three sections have been analysed: A, B and C. In section A increasing pore water pressure has been observed at the downstream side of the dam. Thereby it has been concluded that a new drainage system is needed; new trenches of large size are to be excavated. In section B new toe berms are planned, due to the requirement that the dam should be able to divert leakage without erosion occurring at the dam toe. This contains soil material that might degrade when stresses are increased, with intensified deformations as a consequence. In section C a new berm is to be constructed, before this can be conducted an excavation is performed at the toe of the dam.The results have shown deformations of an acceptable magnitude and factors of safety that indicate conditions for the planned dam safety measures. Numerical values of deformations and factors of safety can be utilised as an attempt to establish alarm values for the stability of the dam. The finite element method is a useful tool for this kind of evaluation.

  • 1372.
    Toromanovic, Jasmina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mattsson, Hans
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Effects of Measurement Error on the Genetic Algorithm in Soil Parameter Identification for an Earth- and Rockfill Dam2017Inngår i: ICSMGE 2017: 19th International Conference on Soil Mechanics and Geotechnical Engineering, 19th ICSMGE Secretariat , 2017, s. 2443-2446Konferansepaper (Fagfellevurdert)
    Abstract [en]

    It is usually difficult to determine values for soil parameter values in earth- A nd rockfill dams by traditional methods. Field sampling is not easily performed, especially in the impervious parts, since the performance and safety of the dam structure may be affected in an unfavourable way. Therefore other methods, preferably non-destructive, are needed to investigate the mechanical behaviour. Inverse analysis has been utilised to identify soil parameter values for an earth- A nd rockfill dam. An error function and a genetic search algorithm were combined with a finite element software to perform the analysis. The model parameters in the chosen constitutive model were calibrated until the horizontal deformations corresponded to the horizontal inclinometer deformations. Errors or irregularities in field measurements can occur, for instance based on the accuracy of the equipment. In this study, the performance of the genetic algorithm was investigated, when applied to identify soil parameters for a dam. Added perturbations to simulated inclinometer data are randomly generated within a chosen interval of error. The results showed that the genetic algorithm found a minimum for the error function even though the field data was substantially perturbed. Errors up to 10% were shown to have minor impact

  • 1373.
    Toromanovic, Jasmina
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mattsson, Hans
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Effects of random measurement error on the genetic algorithm in soil parameter identification for an earth- and rockfill dam2017Konferansepaper (Annet vitenskapelig)
  • 1374. Trouve, Emmanuel
    et al.
    Mercier, Gregoire
    Fauvel, Mathieu
    Bruzonne, Lorenzo
    Ban, Yifang
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Samhällsplanering och miljö, Geoinformatik.
    Foreword to the Special Issue on Analysis of Multitemporal Data and Applications2016Inngår i: IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, ISSN 1939-1404, E-ISSN 2151-1535, Vol. 9, nr 8, s. 3356-3358Artikkel i tidsskrift (Annet vitenskapelig)
  • 1375.
    Tsegay, Haftom Tesfay
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Vibration caused by sheet pile driving- effect of driving equipment2018Independent thesis Advanced level (degree of Master (Two Years)), 80 poäng / 120 hpOppgave
    Abstract [en]

    In many construction works in urban areas vibratory driving is the most widely used technique toinstall sheet piles. But due to vibration-sensitive equipment and structures the amount of inducedground vibration need to be minimized. Hence, it is important to select appropriate vibratorparameters that will minimize the level of induced ground vibration.The main objective of this thesis is to study the effect of the vibratory parameter eccentricmoment (vibrator displacement amplitude) on the induced ground vibration during sheet piledriving. To achieve the objective, a literature review and a full-scale field test has beenconducted. The literature review was conducted to provide guidance for the evaluation of thefield test results.The field study was performed in Uppsala in June 2018, where a series of six sheet pile drivingtests were conducted, the first three sheet piles were driven with lower vibrator displacementamplitude and the next three with higher vibrator displacement amplitude, but the same drivingfrequency was used for all six sheet piles. Five tri-axial accelerometers were used to measure thevibration amplitude on vibrator, sheet pile and ground.Important findings of the field study confirmed that, driving sheet piles with higher eccentricmoment will induce lower ground vibration and higher sheet pile penetration speed incomparison to driving with lower eccentric moment. Limitations and possible future researchworks are pointed out.

  • 1376.
    Tvinghagen, Adam
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Jord- och bergmekanik.
    Arching Stability in Shallow Tunnels: A comparison between analytical and numerous solutions2016Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
  • 1377.
    Umar, Sraj Banda
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sjöberg, Jonny
    tasca Consultants AB, Luleå.
    Savilahti, Thomas
    Loussavaara-Kiirunavaara AB (LKAB) Malmberget Mine, Gällivare.
    Modelling of caving and deformation mechanisms of the hangingwall of the Printzsköld oreboby at Malmberget mine2017Inngår i: The Southern African Journal of Mining and Metallurgy, ISSN 2225-6253, E-ISSN 1543-9518, Vol. 117, nr 4, s. 351-360Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sublevel caving in Malmberget mine results in mining-induced surfacedeformation. One of the currently mined orebodies is the Printzsköldorebody. As mining deepens there is need to assess the behaviour of thecave formed in the subsurface above this orebody. Numerical analysis wasused to assess the effects of extraction to deeper levels and performstrength parametric studies. Stress redistribution was studied, and theresults showed high stress buildups in the hangingwall and the crownpillar. Two failure mechanisms have been identified – shear and tensile.Reducing cohesion by 50% increased the area of the yielded zone by morethan 100% in the hangingwall.

  • 1378.
    Uotinen, Lauri
    et al.
    Aalto University, Finland.
    Korpi, Eero
    Aalto University, Finland.
    Hartikainen, Ari
    Aalto University, Finland.
    Yorke, Raphael
    Aalto University, Finland.
    Johansson, Fredrik
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE).
    Rinne, Mikael
    Aalto University, Finland.
    A method to downscale joint surface roughness and to create replica series using 3D printed molds2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In order to determine the in-situ shear strength of rock joints, large scale testing is required. However, this is both expensive and difficult to execute. One possible method to overcome this may be to use photogrammetry to capture large joint surface roughness in-situ and downscale it to replica samples, which could be sheared in laboratory. In this paper, as a first part in such a method, a technique to digitize surface roughness and to produce replica samples for laboratory shear testing from a larger joint sample are presented. First, a thin granitic rock slice with dimensions of 1.75 m x 0.95 m of granitic intact rock was chosen for the study. The joint surface is fresh and created through tensile induced splitting. The large joint sample is digitized using photogrammetry. Then, one full-scale 1.7 m x 0.6 m geometry is cropped from the digitized joint geometry and then subsamples at 10x, 7.5x, 5x, 2.5x and 1x scales. All sub-geometries are scaled down digitally to produce 0.17 m by 0.06 m geometries. The geometries are used to make casting molds both positive and negative to produce samples with perfect matedness. The casting molds are 3D printed in polylactic acid plastic and C60/75 concrete is cast to produce a replica series. In addition to the creation of this replica series, two pilot replicas are also tested using a portable shear box with a 0.5 MPa normal pressure. The results from the pilot rounds are presented and discussed. Finally, suggestions for future research are given.

  • 1379.
    Vahdati, Pooya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    CFD simulation of water behavior in bottom outlet channel of Storfinnforsen dam2010Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The focus of this project is to simulate the water behavior downstream of the Storfinnforsen dam, located in the centre of Sweden. Specifically, this will compare a simulation of the water in the curved channel after the bottom outlet to results obtained from hydraulic physical modeling tests carried out by Vattenfall R & D company at Älvkarleby laboratory. The parameters of velocity, depth of water while the gate is fully open and the variable level of water in the reservoir were compared with the velocity and depth parameters found in the physical model.

  • 1380.
    Vahdati, Pooya
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Identification of soil parameters in an embankment dam by mathematical optimization2014Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The finite element method (FEM) has been widely used to analyse earth and rockfill dams. In a finite element analysis a proper constitutive model has to be chosen for each part of the dam in order to simulate the relation between stresses and strains. The zones of an earth and rockfill dam have different functions. Because of that the zones normally consist of various soil types for which the stress/strain response could vary considerably. For each dam zone, suitable values have to be assigned to the parameters included in the constitutive model chosen. In general, laboratory tests and/or field tests of the soil are needed as a basis for this parameter evaluation. However, many dams are old and limited information might be available regarding the soil materials being used in the dam structures. In dams, it is normally very difficult to take up soil samples for testing, especially from the central impervious part, since this might affect the dam performance and the safety of the dam. For dams it would be advantageous if constitutive parameter values could be determined with some non-destructive method. Inverse analysis provides a possibility to determine the constitutive behaviour of different materials within the dam structure under the condition that the dams have been equipped with various instrumentations, for monitoring dam performance, which record data such as pore pressures, deformations, total stresses and seepage etc. In the method of inverse analysis, two separate parts are included: (1) an optimization method consisting of an error function and a search algorithm and (2) a numerical method to solve the partial differential equations arising in stress-strain analysis of structures. In this study, inverse analysis of a dam case was performed with a commercial finite element program Plaxis and the genetic algorithm was utilized as the search algorithm in the optimization method. The genetic algorithm was chosen due to its robustness and efficiency, particularly since it provides a set of solutions close to the optimum solution instead of one unique answer; a set of solutions is more practical from a geotechnical perspective. In the proposed inverse analysis a finite element model is calibrated automatically by changing the values of the input parameters of the selected constitutive model in different dam zones until the discrepancy between the measured results by dam instrumentations and the corresponding computed results is minimized.In order to examine the efficiency and robustness of the genetic algorithm, the research was initially focused on a synthetic case study. The synthetic case, a set of model parameters known in advance, is a good test of the mathematical basis used in the optimization, i.e. the objective function and the search algorithm. The Mohr-Coulomb model was chosen for all dam zones, as an initial choice for this research, chiefly because of its simplicity. A very good agreement for the optimization against the synthetic case was obtained. The practical outcome of an inverse analysis clearly depends on the ability of the constitutive models chosen to capture the real soil behaviour in the different dam zones. A proper choice of a constitutive model provides an opportunity to calibrate the finite element model properly. Therefore, in the next step the Hardening soil model, an advanced constitutive model, was chosen for optimization on the dam. In this part of the research, two cases (A and B) based on different reservoir water levels and number of berms constructed, were analysed. All the data of horizontal displacement were received from exactly the same positions in the geometry as the measurements carried out with the single inclinometer. The results of inverse analyses showed that the Hardening soil model is able to capture better the soil displacements within the dam structure, especially at the crest part, compared to the Mohr-Coulomb model.Finally, it was concluded that inverse analysis is a practical tool for identifying soil material properties of earth and rockfill dams and provides a non-destructive method for dam engineers to obtain more information about the dams. Moreover, if inverse analysis applications become available in commercial finite element software, it would certainly be a valuable tool for dam engineers assessing dam performance and dam safety.

  • 1381.
    Vahdati, Pooya
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Levasseur, Séverine
    Département ArGEnCo Service de Géomécanique et géologie de l'ingénieur Université de Liège.
    Mattsson, Hans
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Inverse Hardening Soil Parameter Identification of an Earth and Rockfill Dam by Genetic Algorithm Optimization2014Inngår i: The Electronic journal of geotechnical engineering, ISSN 1089-3032, E-ISSN 1089-3032, Vol. 19, nr N, s. 3327-3349Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a study of identification of constitutive parameter values in the Hardening soil model by inverse analysis of an earth and rockfill dam application. The authors have experience from a previous study on the same case with the Mohr-Coulomb model. The objective of this research is to examine if the inverse analysis technique can be successfully used for this type of application and choice of constitutive model. The values of soil parameters are determined based on horizontal deformations obtained from installed instrumentations in the dam. The quantities that are monitored in the dam can be numerically predicted by a finite element simulation. In inverse analysis, constitutive parameter values are chosen in such a way that the error between data recorded by measurements in the dam and numerical simulation is minimized. An optimization method based on the genetic algorithm was applied to search for the minimum error in the search domain in this study. Optimizations have initially been performed in a large search domain in order to find a criterion identifying the best solutions. Thereafter, the optimizations were limited to this criterion in order to find the best set of solutions close to the optimum point. Moreover, the error function topology and smoothness was examined as well. It was overall concluded, that the inverse analysis technique could be effectively used for earth and rockfill dam applications, despite the fact that the technique is expensive in terms of computational time.

  • 1382.
    Vahdati, Pooya
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Levasseur, Séverine
    Département ArGEnCo Service de Géomécanique et géologie de l'ingénieur Université de Liège.
    Mattsson, Hans
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Inverse Mohr-Coulomb soil parameter identification of an earth and rockfill dam by genetic algorithm optimization2013Inngår i: The Electronic journal of geotechnical engineering, ISSN 1089-3032, E-ISSN 1089-3032, Vol. 18, nr X, s. 5419-5440Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a study of identification of constitutive parameter values in the Mohr-Coulomb model by inverse analysis of an earth and rockfill dam application. The objective is to examine if the technique of inverse analysis can be effectively used for this type of case. The values of soil parameters are determined based on horizontal deformations recorded from installed instrumentations in the dam. The quantities that are monitored in the dam can be numerically predicted by a finite element simulation. In inverse analysis, constitutive parameter values are chosen in such a way that the error between data obtained by measurements in the dam and numerical simulation is minimized. An optimization method based on the genetic algorithm was utilized to search for the minimum error in this study. Optimizations have been performed against both a synthetic and a real dam case. The effect of the population size in the genetic algorithm was also analysed for this case in order to approach a proper set of solutions close to the optimum point by considering: the finite element computation time and the error function values. The error function topology was examined as well, and it was found to be complex and noisy for this application. The genetic algorithm is known to be a practically good choice of search method for such complicated topologies. It was overall concluded, that the inverse analysis technique studied, could be effectively used for this kind of earth and rockfill dam application despite the fact that, the technique is expensive in terms of computational costs. Inverse analysis has the potential to become a valuable tool for dam engineers assessing dam performance and dam safety if it becomes readily available in commercial finite element software.

  • 1383.
    Vahdati, Pooya
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Levasseur, Séverine
    Université de Liège.
    Mattsson, Hans
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Inverse soil parameter identification of an earth and rockfill dam by genetic algorithm optimization2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The paper presents a study of constitutive parameter value identification by inverse analysis on an earth and rockfill dam application. The objective is to examine if the technique of inverse analysis can be effectively used for this type of case. In the inverse analysis procedure discussed here, values of constitutive parameters are determined based on data recorded from installed instrumentations in the dam. The quantities that are monitored in the dam can be numerically predicted by a finite element simulation. To perform a finite element simulation, constitutive models have to be chosen and values have to be assigned to the parameters included. In inverse analysis, constitutive parameter values are chosen in such a way that the error between data obtained by measurements in the dam and numerical simulation is minimized. This is accomplished by optimization. The genetic algorithm was utilized as the optimization strategy, to search for the minimum error, in this study. Optimizations have been performed both against a synthetic dam case and a real dam case. It was concluded, that the inverse analysis technique studied, could be effectively used for this kind of earth and rockfill dam application. However, the technique was time consuming. Inverse analysis has the potential to become a valuable tool for dam engineers assessing dam performance and dam safety if it becomes readily available in commercial finite element software.

  • 1384.
    van Eldert, Jeroen
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Analysis of Excavation Damage, Rock Mass Characterisation and Rock Support Design using Drilling Monitoring2018Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Prior to an underground excavation a site investigation is carried out. This includes reviewing and analysing existing data, field data collected through outcrop mapping, drill core logging and geophysical investigations. These data sources are combined and used to characterise, quantify and classify the rock mass for the tunnel design process and excavation method selection.

    Despite the best approaches used in a site investigation, it cannot reveal the required level of detail. Such gaps in information might become significant during the actual construction stage. This can lead to; for example, over-break due to unfavourable geological conditions. Even more so, an underestimation of the rock mass properties can lead to unplanned stoppages and tunnel rehabilitation. On-the-other-hand, the excavation method itself, in this case, drill and blast, can also cause severe damage to the rock mass. This can result in over-break and reduction of the strength and quality of the remaining rock mass. Both of these attributes pose risks for the tunnel during excavation and after project delivery.

    Blast damage encompasses over-break and the Excavation Damage Zone (EDZ). In the latter irreversible changes occur within the remaining rock mass inside this zone, which are physically manifested as blast fractures. In this thesis, a number of methods to determine blast damage have been investigated in two ramp tunnels of the Stockholm bypass. Herein, a comparison between the most common methods for blast damage investigation employed nowadays is performed. This comparison can be used to select the most suitable methods for blast damage investigation in tunnelling, based on the environment and the available resources. In this thesis Ground Penetrating Radar, core logging (for fractures) and P-wave velocity measurements were applied to determine the extent of the blast damage.

    Furthermore, the study of the two tunnels in the Stockholm bypass shows a significant overestimation of the actual rock mass quality during the site investigation. In order to gain a more accurate picture of the rock mass quality, Measurement While Drilling (MWD) technology was applied. The technology was investigated for rock mass quality prediction, quantifying the extent of blast damage, as well as to investigate the potential to forecast the required rock support. MWD data was collected from both grout and blast holes. These data sets were used to determine rock quality indices e.g. Fracture Indication and Hardness Indicator calculated by the MWD parameters. The Fracture Index was then compared with the installed rock support at the measurement location.

    Lastly, the extent of the damage is investigated by evaluating if the MWD parameters could forecast the extent of the EDZ. The study clearly shows the capability of MWD data to predict the rock mass characteristics, e.g. fractures and other zones of weakness. This study demonstrated that there is a correlation between the Fracture Index (MWD) and the Q-value, a parameter widely used to determine the required rock support. The study also shows a correlation between the extent of the blast damage zone, MWD data, design and excavation parameters (for example tunnel cross section and charge concentration).

  • 1385.
    van Eldert, Jeroen
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi. Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mining and Geotechnical Engineering - Swedish Blasting Research Centre.
    Schunnesson, Håkan
    Johansson, Daniel
    Saiang, David
    Measurement While Drilling to Predict Rock Mass Quality and SupportManuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    A tunnelling project is normally initiated with a site investigation to determine the in-situ rock mass conditions and to generate the basis for the tunnel design and rock support. However, since site investigations often are based on limited information (surface mapping, geophysical profiles, few bore-holes, etc.), the estimation of the rock mass conditions may contain inaccuracies, resulting in underestimating the required rock support. The study hypothesised that these inaccuracies could be reduced by using Measurement While Drilling (MWD) technology to assist in the decision-making process. A case study of two tunnels in the Stockholm bypass found the rock mass quality was severely overestimated by the site investigation; more than 45% of the investigated sections had a lower rock mass quality than expected. MWD data were recorded in 25m grout holes and 6m blast holes. The MWD data were normalised so that the long grout holes with larger hole diameters and the shorter blast holes with smaller hole diameters gave similar results. With normalised MWD data, it was possible to mimic the tunnel contour mapping; results showed good correlation with mapped Q-value and installed rock support. MWD technology can improve the accuracy of forecasting the rock mass ahead of the face. It can bridge the information gap between the early, somewhat uncertain geotechnical site investigation and the geological mapping done after excavation to optimise rock support.

  • 1386.
    Vestman, Marcus
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser.
    Modeling of pore pressure in a railway embankment2018Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    LKAB and Trafikverket want to increase the maximum allowed axial load from 30 tons to 32,5 tons for the northern part of Malmbanan. There are ongoing investigations of the condition of the railway with the current axial load of 30 tons. The investigations do not include one of Trafikverket's concerns about the condition of the railway. That question is how the periodical load from trains affect the stability and maintenance cost of the railway embankment. The aim of this thesis is therefore to do a preliminary investigation of how the excess pore pressure is developed in the railway embankment during periodical loading and an attempt to model it the help of PLAXIS2D, a finite element software.

    PLAXIS2D has been used to model a simplified section of section km 1449+820 that is subjected by periodical loading with an axial load of 30 tons. There are 6 created models in the thesis where model 2-6 origin from model 1 but with some minor changes. The changes between the models are the train speed, groundwater level, width of the embankment and load. The periodical load applied in all models has been assumed to load the embankment with a periodical shape of a sinus curve.

    From the models, the distribution of the effective stress and excess pore pressure have been measured. The total displacement and the magnitude of excess pore pressure in different measuring points in the embankment have also been measured. These results have been used to analyze why there are certain points in the embankment which accumulate excess pore pressure. In the models, measuring points have also been created beneath the sleeper and in the embankment toe where total displacement and effective stress have been measured to relate and see if the response in stress and displacements are trustworthy.

    It was concluded that accumulation of excess pore pressure is relative high in the embankment toe due to the stress distribution and slope stability. The embankment is developing large shear stresses in the embankment toe to resist against slope failure. The excess pore pressure is recommended to be measured in the embankment toe, but it is also recommended to develop the model further since it does not consider any dynamics and neither soil stiffening or soil softening which limit the possibility to analyze liquefaction in detail.

  • 1387.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Compaction and thaw deformation of frozen soil: permeability and structural effects due to freezing and thawing.1997Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis is the result of the two projects:"Deformations in winter compacted soils" and "Permeability changes in a fine-grained till due to freeze/thaw". The aim of the first project was to study whether it is possible to compact frozen soils, in road embankments etc., to a satisfying result as well as to identify the most important factors influencing the compaction result. Different types of soil (fine-grained till and sand) were compacted in the laboratory at the temperatures +20, -2 and -10°C using compaction cylinders of two different sizes (1 dm³). Frozen soil cubes, having a side-length of 5 to 100 mm, were manufactured at different water contents and compacted in frozen state. The tests show that the compaction result decreases with decreasing temperature and increasing water content. However, the influence of the size of the soil cubes was of minor importance and the influence of the testing temperature was significantly smaller than what has been reported in the literature. In addition, compression tests on frozen, compacted soil samples were carried out to measure the thaw settlement. A relation ( a-value), based on the dry density of the frozen and unfrozen soil, was established from which it is possible to estimate the maximum compression taking place when the frozen soil thaws and is loaded. The aim of the second project was to investigate whether structural changes take place in a fine-grained till exposed to cyclic freezing and thawing. It was believed that freeze/thaw cycles could have a negative impact on fine-grained till, e.g. on its function as a hydraulic barrier. The permeability was chosen to be the key parameter to study whether the structure was affected of freezing and thawing or not. In addition, tests were directed to measure possible movements of small particles and stones due to freezing and thawing. In the laboratory, unfrozen soil was compacted to different void ratios into a rigid wall opermeameter and the permeability was measured. Thereafter, the sample was frozen and thawed a number of cycles. The samples were frozen one dimensionally in a closed pore water system and the permeability was measured in the thawed soil after a certain number of cycles. In addition, the particle movements were measured by granulometric tests and the stone movements by a specially developed X-ray technique. The investigations showed that the permeability in a fine-grained till is influenced by the freeze/thaw cycles. Typically, the permeability increased by 1 to 10 times in an initially dense till and decreased between 1 to 50 times in an initially loose till. The soil exhibited volume changes due to the freeze/thaw cycles and the volume typically decreased for an initially loose soil and increased for a dense soil. A residual void ratio was reached after 1-3 freeze/thaw cycles, independent of the state of the soil structure prior to freezing. The residual void ratio ranged from 0.31 to 0.40 in the studied material. Finally, no particle movements were detected, but significant stone movements in vertical as well horizontal direction were identified.

  • 1388.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Compaction of frozen soils: a laboratory study1994Inngår i: Proccedings: Polartech '94 - International Conference on Development and Commercial Utilization of Technologies in Polar Regions, March 22-25, 1994 Luleå, Sweden, Luleå: Högskolan i Luleå , 1994, s. 109-Konferansepaper (Annet vitenskapelig)
  • 1389.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Egenskaper hos jord packad under vinterförhållanden: en litteraturundersökning1992Rapport (Annet vitenskapelig)
  • 1390.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Frusen jords packnings- och deformationsegenskaper1994Licentiatavhandling, monografi (Annet vitenskapelig)
  • 1391.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Frysnings- och tiningscyklers inverkan på jords permeabilitet: en litteraturundersökning1995Rapport (Annet vitenskapelig)
  • 1392.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laboratory study of stone heave in till exposed to freezing and thawing1998Inngår i: Cold Regions Science and Technology, ISSN 0165-232X, E-ISSN 1872-7441, Vol. 27, nr 2, s. 141-152Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cyclic freezing and thawing of soils affect the structure and might, under certain conditions, cause stones and particles to move and relocate. The movement of stones will influence the soil structure and create weak and loose parts with increased permeability. This phenomenon has been known for a long time, but the knowledge regarding the magnitude of stone heave and soil conditions necessary for heave to take place has been lacking. Therefore, laboratory tests were carried out. Fine-grained till (moraine) was compacted to different void ratios and then saturated in a rigid wall permeameter which was exposed to one-dimensional freezing and thawing in a closed water system. The movements of an embedded stone were measured by an X-ray technique. Unfrozen samples, as well as samples frozen and thawed, were X-rayed and the stone movements were quantified after 1, 2, 4, and 10 cycles of freezing and thawing. The results show that stone movements (vertical and horizontal) take place due to freeze/thaw. The void ratio (the ratio of the volume of void space to the volume of solid substance in the sample) was found to be a key parameter for whether upward or downward stone movements took place. The downward movement occurred when the soil had a high void ratio, and the upward when the void ratio was small. In the loose soil, the stone first moved downwards and then, when the soil became denser due to freeze/thaw, it changed direction and heaved. In the loose soil, significant movements in the horizontal direction as well as rotation of the stone were also found.

  • 1393.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Permeability and volume changes in till due to cyclic freeze/thaw1998Inngår i: Canadian geotechnical journal (Print), ISSN 0008-3674, E-ISSN 1208-6010, Vol. 35, nr 3, s. 471-477Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A fine-grained nonplastic till was compacted in the laboratory in three types of rigid wall permeameters, having a volume of 0.4, 1.5, and 25 dm3, respectively, and, was thereafter exposed to a maximum of 18 freezing and thawing cycles. The permeabilities in the vertical direction of saturated samples were measured in unfrozen soil as well as in thawed soil. The results show that the permeabilities changed after freezing and thawing. The magnitude of the changes in this study were in the range 0.02-10 times after freeze/thaw compared with the unfrozen soil. Soil exhibited volume changes subsequent to freeze/thaw. The volume typically decreased for an initially loose soil and increased for a dense soil. Independent of whether the initial soil structure was loose or dense, a constant `residual' void ratio, eres, was obtained after 1-3 cycles. For the soil investigated, the residual void ratio ranged from 0.31 to 0.40

  • 1394.
    Viklander, Peter
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Eigenbrod, Dieter
    Lakehead University, Thunder Bay, Ontario.
    Stone movements and permeability changes in till caused by freezing and thawing2000Inngår i: Cold Regions Science and Technology, ISSN 0165-232X, E-ISSN 1872-7441, Vol. 31, nr 2, s. 151-162Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Vertical uplifting of boulders and stones is well known to take place in cold regions. Movements of stones in roads might lead to traffic danger, vehicle failures, and cause breakdown of the road surface with the need of expensive repair as a consequence. In addition, freeze/thaw and associated stone movements may cause an increase in permeability, which can lead to contamination of soils and ground water if used as soil liners in landfill areas or even dam failures if used as hydraulic barriers in earth dams. Freeze/thaw tests were carried out in the laboratory on a silty sandy soil in order to study movements of embedded stones and to measure how the overall permeability was influenced by freeze/thaw cycles. The soil samples were compacted at three different water contents, i.e. 11.5% (optimum), 14.5%, and 17.5%. Each sample contained one stone, placed at a predetermined depth. The soil samples were subjected to one-dimensional open system freeze/thaw. Soil temperatures, volume changes, and stone movements were measured. The results showed that upward stone movements took place due to freeze/thaw in the frost susceptible soil compacted at and 3% above the optimum water content. In addition, the permeability increased in samples with initial water contents of 11.5% and 14.5%. This permeability increase was as much as 81 times after six freeze/thaw cycles. For the samples with initial water contents of 17.5%, very small changes in permeability were measured. Vertical uplifting of boulders and stones is well known to take place in cold regions. Movements of stones in roads might lead to traffic danger, vehicle failures, and cause breakdown of the road surface with the need of expensive repair as a consequence. In addition, freeze/thaw and associated stone movements may cause an increase in permeability, which can lead to contamination of soils and ground water if used as soil liners in landfill areas or even dam failures if used as hydraulic barriers in earth dams. Freeze/thaw tests were carried out in the laboratory on a silty sandy soil in order to study movements of embedded stones and to measure how the overall permeability was influenced by freeze/thaw cycles. The soil samples were compacted at three different water contents, i.e. 11.5% (optimum), 14.5%, and 17.5%. Each sample contained one stone, placed at a predetermined depth. The soil samples were subjected to one-dimensional open system freeze/thaw. Soil temperatures, volume changes, and stone movements were measured. The results showed that upward stone movements took place due to freeze/thaw in the frost susceptible soil compacted at and 3% above the optimum water content. In addition, the permeability increased in samples with initial water contents of 11.5% and 14.5%. This permeability increase was as much as 81 times after six freeze/thaw cycles. For the samples with initial water contents of 17.5%, very small changes in permeability were measured. Vertical uplifting of boulders and stones is well known to take place in cold regions. Movements of stones in roads might lead to traffic danger, vehicle failures, and cause breakdown of the road surface with the need of expensive repair as a consequence. In addition, freeze/thaw and associated stone movements may cause an increase in permeability, which can lead to contamination of soils and ground water if used as soil liners in landfill areas or even dam failures if used as hydraulic barriers in earth dams. Freeze/thaw tests were carried out in the laboratory on a silty sandy soil in order to study movements of embedded stones and to measure how the overall permeability was influenced by freeze/thaw cycles. The soil samples were compacted at three different water contents, i.e. 11.5% (optimum), 14.5%, and 17.5%. Each sample contained one stone, placed at a predetermined depth. The soil samples were subjected to one-dimensional open system freeze/thaw. Soil temperatures, volume changes, and stone movements were measured. The results showed that upward stone movements took place due to freeze/thaw in the frost susceptible soil compacted at and 3% above the optimum water content. In addition, the permeability increased in samples with initial water contents of 11.5% and 14.5%. This permeability increase was as much as 81 times after six freeze/thaw cycles. For the samples with initial water contents of 17.5%, very small changes in permeability were measured.

  • 1395.
    Viklander, Peter
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Deformation and compaction of frozen soils1994Inngår i: Ground freezing 94: proceedings of the seventh International Symposium on Ground Freezing, Nancy, France, 24-28 October 1994 / [ed] Michel Fremond, Rotterdam: Balkema Publishers, A.A. / Taylor & Francis The Netherlands , 1994, s. 109-116Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Frozen soils compaction are understood to give fills with low densities. Thus, relatively large deformations often occur when such fills melts. The most important factors influencing the obtained dry density, and consequently the thaw deformations, are compaction effort, temperature, water/ice content and soil type. A laboratory investigation was conducted in order to quantify the different factors influencing the obtained degree of compaction, as well as related thaw deformation. The results indicated that the water content of the soil is the most important factor for the obtained dry densities and for the thaw compressions

  • 1396.
    Viklander, Peter
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hur påverkas jord av frysning och tining2000Inngår i: Bygg & Teknik, ISSN 0281-658X, Vol. 92, nr 1, s. 59-61Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 1397.
    Viklander, Peter
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laboratoriepackning av frusen jord1995Inngår i: 12th Nordiska Geoteknikermötet, June 26-28, 1996, Reykjavik, Iceland, 1995, s. 159-168Konferansepaper (Annet vitenskapelig)
  • 1398.
    Viklander, Peter
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laboratory study of the compaction properties of frozen soils1993Inngår i: Frost in geotechnical engineering: proceedings of the 2nd international symposium on Frost geotechnical engineering, Rotterdam: Balkema Publishers, A.A. / Taylor & Francis The Netherlands , 1993, s. 69-77Konferansepaper (Fagfellevurdert)
  • 1399.
    Viklander, Peter
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Permeability changes in a fine-grained till du to cycles of freezing and thawing1997Inngår i: Ground Freezing 97: frost action in soils : proceedings of the International Symposium on Ground Freezing and Frost Action in Soils / Luleå / Sweden / 15-17 April 1997 / [ed] Sven Knutsson, Rotterdam: Balkema Publishers, A.A. / Taylor & Francis The Netherlands , 1997, s. 193-202Konferansepaper (Fagfellevurdert)
  • 1400.
    Viklander, Peter
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Uppfrysning av block och stenar i vägar1999Inngår i: Bygg & Teknik, ISSN 0281-658X, Vol. 92, nr 1, s. 39-41Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
25262728293031 1351 - 1400 of 1520
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