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  • 1. Abitew, Aymiro
    et al.
    Zeinali, Amin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hydraulic conductivity of tailings deposit used as dam construction material at Aitik mine in Sweden2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Distribution of vertical and horizontal hydraulic conductivity and their correlation to geotechnical parameters affecting the hydraulic conductivity of tailings deposit at Aitik mine have been determined. The investigation was carried out along three sections which cover approximately 3km2 of area and 4-5meters of thickness. 3-5 test pits have been excavated in each section and samples are collected from various levels. The horizontal hydraulic conductivity has been found to have a good relation with fraction of fine particles in the deposit and void ratio. However, similar to the results of Jantzer et al (2008) from the same mine, the vertical hydraulic conductivity did not correspond to void ratio. According to evaluation of existing empirical relations to estimate hydraulic conductivity from particle size analysis, Hazen formula (1911) gives 25 and 45 times the measured values of vertical and horizontal hydraulic conductivity respectively. On the other hand, Chapuis et al (2003) has not been succeeded for prediction of hydraulic conductivity of undisturbed samples from the investigated area. However, it gives comparatively good prediction of hydraulic conductivity for disturbed samples which are compacted to their field dry density.

  • 2. Abitew, Aymiro
    et al.
    Zeinali, Amin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hydraulic conductivity of tailings sand used for dam construction at Aitik mine in Sweden2012Ingår i: SWEMP 2012: International symposium on Environmental Issues and Waste Management in Energy and Mineral Production, 2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Distribution of vertical and horizontal hydraulic conductivity and their correlation to geotechnical parameters affecting the hydraulic conductivity of tailings deposit at Aitik mine have been determined. The investigation was carried out along three sections which cover approximately 3km2 of area and 4-5meters of thickness. 3-5 test pits have been excavated in each section and samples are collected from various levels. The horizontal hydraulic conductivity has been found to have a good relation with fraction of fine particles in the deposit and void ratio. However, similar to the results of Jantzer et al (2008) from the same mine, the vertical hydraulic conductivity did not correspond to void ratio. According to evaluation of existing empirical relations to estimate hydraulic conductivity from particle size analysis, Hazen formula (1911) gives 25 and 45 times the measured values of vertical and horizontal hydraulic conductivity respectively. On the other hand, Chapuis et al (2003) has not been succeeded for prediction of hydraulic conductivity of undisturbed samples from the investigated area. However, it gives comparatively good prediction of hydraulic conductivity for disturbed samples which are compacted to their field dry density.

  • 3.
    Dagli, Deniz
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Zeinali, Amin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Gren, Per
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Image analyses of frost heave mechanisms based on freezing tests with free access to water2018Ingår i: Cold Regions Science and Technology, ISSN 0165-232X, E-ISSN 1872-7441, Vol. 146, s. 187-198Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A freezing test apparatus was supplemented with a camera to allow for recording and monitoring one-dimensional freezing tests to analyze the development of ice lenses via particle image velocimetry (PIV) in the laboratory. Two tests on disturbed, partially saturated samples of silt loam were conducted. Image recording and correlation analyses provided detailed information about frost front penetration and ice lens formation(s) under varying temperature boundary conditions. Thawing has also been regarded in further studies.

    Results of the image analyses were compared to readings from conventional displacement measurements during the same test. Significant agreement between the results of image analyses and displacement measurements has been found. Test results were also used to establish a qualitative relationship between heat extraction and heave rates. Advantages and disadvantages of utilizing image analysis methods were discussed. Potential remedies for overcoming the drawbacks of using image analysis are suggested.

    Image analysis is shown to be a viable method in further understanding of frost heave mechanisms.

  • 4.
    Dagli, Deniz
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Zeinali, Amin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Edeskär, Tommy
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Theoretical Analysis of the Relationship between Heave and Net Heat Extraction Rates Based on Freezing Experiments2016Ingår i: Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM: Reykjavik, Iceland 25th – 28th of May 2016, 2016, s. 411-421Konferensbidrag (Refereegranskat)
    Abstract [en]

    In order to improve the current design of roads against frost action, the Swedish Transport Administration (Trafikverket) has initiated a research programme. The main goals of the research are to revise the existing frost design models and the frost susceptibility classification system for subgrade soils.A qualitative theoretical analysis to establish a relationship between frost heave and net heat extraction rates based on experimental data has been done. Experiments were carried on disturbed (hand compacted), saturated samples of same type of soil without any overburden. Several different cold end temperatures were applied to create different boundary conditions to make a more detailed analysis.Results were analysed and compared to those of other researchers while pointing out the similarities and differences. Potential reasons for these differences have been identified. Based on the findings of the experimental work, suggestions for improvements are given for future testing. Some preliminary results providing hints for the relationship between segregational heave and net heat extraction rates were obtained. At the end it was shown that there exists a significant difference between the findings of the experimental work and the current system being used in Sweden in order to quantify heave.

  • 5.
    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 (Övrigt vetenskapligt)
    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.

  • 6.
    Zeinali, Amin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Thaw Mechanism in Subgrades2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Freezing-thawing, changes the properties of soil due to the phase change of the water in the soil body. Freezing-thawing cycles in the soil have been studied for several decades including extensive laboratory research. In this study, the main focus is thawing based on laboratory investigation. The soil used in the laboratory study is taken from a minor road where an additional field study has been carried out.

    A freezing-thawing laboratory apparatus is manufactured and used in order to get better understanding of the freezing-thawing process. The apparatus is designed for cylindrical sample, one dimensional heat flow, freezing/thawing from top to bottom, water supply from bottom (access to external water) and possible to apply overburden load.

    he laboratory tests were conducted at similar soil samples at different boundary conditions. Water is liberated in the thawing zone of the sample. During thawing the only drainage path is to the surface, however, water migrates upwards even when entire soil is thawed. Upwards water migration after thawing period can be due to the changes in thawed soil properties such as permeability and fine particles redistribution. The rate of thawing is a very important factor for thawing conditions. At low thawing rate the drainage capacity of sample is sufficient to drain the liberated water from ice. Moreover, freezing condition i.e. access to water, has high impact on thawing process. If the volume of ice lenses is high,the thawed soil fluidizes as the water migrates upwards. Pore pressure transducers will be added to the apparatus for further investigation regarding both freezing and thawing.

    The field study has been conducted in order to study thaw behavior in low volume road embankment. The scope of the study is to investigate the thaw weakening progress by Falling Weight Deflectometer (FWD) and Dynamic Cone Penetration (DCP) tests on low volume embankment road near Luleå,northern Sweden. The results from methods is compared and the differences in how they are capturing the thawing is discussed. DCP which is known as an easy and cheap method to estimate stiffness of soil layers is applied to estimate thawing period and the layer which thaw weakening takes place at. Stiffness gained by back calculation of FWD results which is performed on the same road embankment and same period of time DCP test is done.

  • 7.
    Zeinali, Amin
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Dagli, Deniz
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Edeskär, Tommy
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Freezing-Thawing Laboratory Testing of Frost Susceptible Soils2016Ingår i: Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM: Reykjavik, Iceland 25th – 28th of May 2016, 2016, s. 267-276Konferensbidrag (Refereegranskat)
    Abstract [en]

    Frost heave and thaw weakening are two common concerns in designing and constructing roads throughout cold region areas. Cold regions can be defined in terms of air temperature and frost penetration by frozen ground engineering. Researchers have been studying frost action in soil for the past 85 years in order to design ways to reduce the costly damage to roads. Conducting the test on frost-susceptible soil must be done in order to retrieve data for frost heave and thaw weakening modeling in the soil body during a certain freezing-thawing cycle. This paper reviews and discusses the apparatuses used for this purposes. The studied apparatuses are cylindrical and provide heat through one dimension. The studied apparatuses mostly differ in the diameter and length of their cylindrical cell; likewise, temperature gradients differ from one apparatus toanother. In this study the LTU’s apparatus which was primarily designed to investigate the research related questions concerning freezing and thawing phenomena is presented in detail. The theory of segregation potential is applied for evaluation of the frost heave test and the thaw consolidation theory is applied for the thaw test. The main goal of the project is to conduct a series of experimental tests on various types of soil while exposing them to frost action in the apparatus to propose a classification system for the different types of soil in question with respect to their susceptibility to the frost action phenomena.

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