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Dagli, Deniz
Publikationer (5 of 5) Visa alla publikationer
Dagli, D., Zeinali, A., Gren, P. & Laue, J. (2018). Image analyses of frost heave mechanisms based on freezing tests with free access to water. Cold Regions Science and Technology, 146, 187-198
Öppna denna publikation i ny flik eller fönster >>Image analyses of frost heave mechanisms based on freezing tests with free access to water
2018 (Engelska)Ingår i: Cold Regions Science and Technology, ISSN 0165-232X, E-ISSN 1872-7441, Vol. 146, s. 187-198Artikel i tidskrift (Refereegranskat) Published
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.

Ort, förlag, år, upplaga, sidor
Elsevier, 2018
Nationell ämneskategori
Geoteknik Teknisk mekanik
Forskningsämne
Geoteknik; Experimentell mekanik
Identifikatorer
urn:nbn:se:ltu:diva-66263 (URN)10.1016/j.coldregions.2017.10.019 (DOI)000423963300021 ()
Anmärkning

Validerad;2018;Nivå 2;2017-12-21 (andbra)

Tillgänglig från: 2017-10-25 Skapad: 2017-10-25 Senast uppdaterad: 2018-04-19Bibliografiskt granskad
Dagli, D. (2017). Laboratory Investigations of Frost Action Mechanisms in Soils. (Licentiate dissertation). Luleå: Luleå University of Technology
Öppna denna publikation i ny flik eller fönster >>Laboratory Investigations of Frost Action Mechanisms in Soils
2017 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Phase change of the water in the soil skeleton under cold climate conditions (also known as frost action in soils) affects soil properties and can be responsible for serious alterations in a soil body; causing damages (due to the volumetric expansion known as frost heave) to structures on or below the ground surface such as foundations, roads, railways, retaining walls and pipelines, etc. In order to improve the current design methods for roads against frost action, the Swedish Transport Administration (Trafikverket) has initiated a research program. The main goals of the program are to revise the existing frost heave estimation methods and improve the frost susceptibility classification system for subgrade soils.

Literature was reviewed to gather the details of different freezing test equipment around the world and to identify common trends and practices for laboratory freezing tests. Based on the literature review and the collaboration with the University of Oulu, Finland an experimental apparatus was assembled for studying frost action in the laboratory. A detailed description of the experimental apparatus is given. Top to down freezing of specimens (of 10cm height and diameter) can be monitored while keeping track of water intake, vertical displacements (heave) and the temperature profile within the sample. Loads can be applied at the top of the sample to study the effects of overburden. Moreover, the test setup was modified with a camera system to have the option of recording the experiments.

Disturbed samples of two different soil types were tested. Experiments with fixed and varying temperature boundary conditions were conducted to assess the validity of the assumptions for the frost heave estimation methods currently in use in Sweden. To this end, a qualitative relationship between frost heave and heat extraction rates based on theoretical equations was established. It was shown that there is a significant difference between the preliminary findings of the experimental work and the current system being used in Sweden to quantify heave.

Image analysis techniques were used on two experiments that were recorded by the camera system. 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. Image analysis was shown to be a viable method in further understanding of frost heave mechanisms.

Shortcomings and disadvantages of utilizing the theoretical equations as well as the image analysis techniques were discussed. Potential remedies for overcoming the drawbacks associated with each approach are suggested. The work is concluded by discussing the potential improvements, planned upgrades (addition of pore pressure transducers) and the future experiments to be conducted.

Ort, förlag, år, upplaga, sidor
Luleå: Luleå University of Technology, 2017
Nyckelord
Cold Regions Soil Mechanics, Frost Action, Frost Depth, Frost Heave, Heat Flow in Soils, Ice Lens Formation, Image Analysis, Laboratory Freezing Test
Nationell ämneskategori
Geoteknik
Forskningsämne
Geoteknik
Identifikatorer
urn:nbn:se:ltu:diva-64184 (URN)978-91-7583-924-0 (ISBN)978-91-7583-925-7 (ISBN)
Presentation
2017-09-01, F1031, Luleå, 10:00 (Engelska)
Opponent
Handledare
Tillgänglig från: 2017-06-19 Skapad: 2017-06-19 Senast uppdaterad: 2017-11-24Bibliografiskt granskad
Zeinali, A., Dagli, D. & Edeskär, T. (2016). Freezing-Thawing Laboratory Testing of Frost Susceptible Soils (ed.). In: (Ed.), (Ed.), Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM: Reykjavik, Iceland 25th – 28th of May 2016. Paper presented at Nordic Geotechnical Meeting : Challanges in Nordic Geotechnics 25/05/2016 - 27/05/2016 (pp. 267-276).
Öppna denna publikation i ny flik eller fönster >>Freezing-Thawing Laboratory Testing of Frost Susceptible Soils
2016 (Engelska)Ingår i: Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM: Reykjavik, Iceland 25th – 28th of May 2016, 2016, s. 267-276Konferensbidrag, Publicerat paper (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.

Serie
Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM
Nyckelord
Civil engineering and architecture - Geoengineering and mining engineering, Frost action, Frost heave, Samhällsbyggnadsteknik och arkitektur - Geoteknik och gruvteknik
Nationell ämneskategori
Geoteknik
Forskningsämne
Geoteknik; Hållbara transporter (FOI)
Identifikatorer
urn:nbn:se:ltu:diva-30685 (URN)493296d9-7230-46cc-b22d-087fbde05c30 (Lokalt ID)493296d9-7230-46cc-b22d-087fbde05c30 (Arkivnummer)493296d9-7230-46cc-b22d-087fbde05c30 (OAI)
Konferens
Nordic Geotechnical Meeting : Challanges in Nordic Geotechnics 25/05/2016 - 27/05/2016
Anmärkning
Godkänd; 2016; Bibliografisk uppgift: ISBN 978-9935-24-002-6; 20160530 (tomede)Tillgänglig från: 2016-09-30 Skapad: 2016-09-30 Senast uppdaterad: 2018-04-19Bibliografiskt granskad
Dagli, D., Zeinali, A., Laue, J. & Edeskär, T. (2016). Theoretical Analysis of the Relationship between Heave and Net Heat Extraction Rates Based on Freezing Experiments (ed.). In: (Ed.), Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM: Reykjavik, Iceland 25th – 28th of May 2016. Paper presented at Nordic Geotechnical Meeting : Challanges in Nordic Geotechnics 25/05/2016 - 27/05/2016 (pp. 411-421).
Öppna denna publikation i ny flik eller fönster >>Theoretical Analysis of the Relationship between Heave and Net Heat Extraction Rates Based on Freezing Experiments
2016 (Engelska)Ingår i: Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM: Reykjavik, Iceland 25th – 28th of May 2016, 2016, s. 411-421Konferensbidrag, Publicerat paper (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.

Serie
Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM
Nyckelord
Civil engineering and architecture - Geoengineering and mining engineering, Frost action, Frost heave, Samhällsbyggnadsteknik och arkitektur - Geoteknik och gruvteknik
Nationell ämneskategori
Geoteknik
Forskningsämne
Geoteknik
Identifikatorer
urn:nbn:se:ltu:diva-39661 (URN)e7e1aafb-5626-4d7a-976e-8772e5cd3c99 (Lokalt ID)e7e1aafb-5626-4d7a-976e-8772e5cd3c99 (Arkivnummer)e7e1aafb-5626-4d7a-976e-8772e5cd3c99 (OAI)
Konferens
Nordic Geotechnical Meeting : Challanges in Nordic Geotechnics 25/05/2016 - 27/05/2016
Anmärkning

Godkänd; 2016; Bibliografisk uppgift: ISBN 978-9935-24-002-6; 20160530 (tomede)

Tillgänglig från: 2016-10-03 Skapad: 2016-10-03 Senast uppdaterad: 2018-04-19Bibliografiskt granskad
Alakangas, L., Dagli, D. & Knutsson, S. (2013). Literature review on potential geochemical and geotechnical effects of adopting paste technology under cold climate conditions (ed.). Paper presented at . Luleå: Luleå tekniska universitet
Öppna denna publikation i ny flik eller fönster >>Literature review on potential geochemical and geotechnical effects of adopting paste technology under cold climate conditions
2013 (Engelska)Rapport (Övrigt vetenskapligt)
Abstract [en]

The purpose of this literature review is to summarize the recent research regarding geochemical and geotechnical stability of paste tailings, identify knowledge gaps and future research needs. The present study has been conducted by the Division of Geosciences and Environmental Engineering together with the Division of Mining and Geotechnical Engineering at Luleå University of Technology on behalf of Boliden Mineral, LKAB and Outotec.A survey conducted by MEND (Mine Environment Neutral Drainage) in 2006 on the environmental effects related to the use of paste tailings summarizes that only a few studies had been performed about long-term effects on the surface and groundwater quality. Instead, the focus had been on the additives and the strength of the paste. It is still uncertain how the paste technology affects the long-term environmental stability from a geochemical point of view. Concerns regarding the stability of paste with high sulphide content are still relevant. Studies performed indicate that sulphide oxidation occurs within cemented paste as well as on the surface of non-cemented paste and cracks formed on the surfaces could induce oxidation. For cemented paste, metals released by sulphide oxidation might be sequestered due to high pH induced by the alkaline additives, but anion such as Se has been shown to be mobilized. The leachate has been shown to be near-neutral initially, but the neutrality decreases with time and probably metals sequestered in the matrix will also be released. Again, it should be noted that no long term study was performed on leaching of paste, cemented or uncemented. The longest leaching study was performed for one year. Arsenic has been proven to be retained in Ca-arsenates in cemented paste, but the long term stability of these precipitates is relatively unknown. Expanded secondary phases e.g. gypsum and ettringite have been observed to form when there is sulphate in the process or drainage of water. These phases could crack the paste, but, on the other hand, can also fill former cracks when deposited in layers. The effects of the formation of these phases are relatively uncertain in a long-term perspective. Presence of different elements such as ammonium, sulphates and metals in the water has been shown to negatively affect the curing process and therefore water is suggested to be treated before use. The presence of carbon dioxide during the paste formation could also affect the curing process, but could sequester metals in carbonate phases.Geotechnical and rheological properties of paste is well defined and documented. Several case studies have been found in literature providing valuable information about the details of the works being carried out. However, a difficulty has been noted during the investigation of the effects of cold climate conditions when current practice is applied in the colder parts of the world. It is not certain how some specific and vital parameters are going to be affected by cold temperatures. Parameters such as deposition slopes and deposition scheme, strength development of the paste are expected to be responsive to cold climate conditions. There are predictions about which properties are going to be affected in what way, but there is also a need to establish a scientific base for discussion. These have been highlighted as research needs and information gaps at the end of the report.

Ort, förlag, år, upplaga, sidor
Luleå: Luleå tekniska universitet, 2013. s. 36
Nyckelord
paste tailings, thickened tailings, tailings geochemistry, cold climate, tailings properties, tailings disposal, Civil engineering and architecture - Geoengineering and mining engineering, Samhällsbyggnadsteknik och arkitektur - Geoteknik och gruvteknik
Nationell ämneskategori
Geoteknik Geokemi
Forskningsämne
Geoteknik; Tillämpad geologi
Identifikatorer
urn:nbn:se:ltu:diva-25066 (URN)da3b398f-0b0e-4c3b-b920-076d89fef9a9 (Lokalt ID)da3b398f-0b0e-4c3b-b920-076d89fef9a9 (Arkivnummer)da3b398f-0b0e-4c3b-b920-076d89fef9a9 (OAI)
Anmärkning
Godkänd; 2013; 20130821 (dendag)Tillgänglig från: 2016-09-29 Skapad: 2016-09-29 Senast uppdaterad: 2019-11-22Bibliografiskt granskad
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