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  • 151. Dury, Robin
    et al.
    Bernander, Stig
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand.
    Kullingsjö, Anders
    Skanska Teknik AB.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Elfgren, Lennart
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand.
    Progressive Landslide Analysis with Bernander Finite Difference Method2017Inngår i: / [ed] Vikas Thakur, Jean-Sébastien L’Heureux, Ariane Locat, 2017, s. 1-Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The poster presents a new Spreadsheet developed by Robin Dury (2017) to simplify the use of the Finite Difference Method developed by Stig Bernander et al (2011, 2016).

    It includes:

    - Material Properties

    - Finite Difference Method

    - Progressive failure process with five phses

    - Discussion

    - References

  • 152. Edeskär, Tommy
    et al.
    Helander, Anders
    SWECO, Östersund.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Numerical analysis of frost penetration around footings of power mills in subarctic conditions2009Inngår i: Proceedings of the 20th International Conference on Port and Ocean Engineering under Arctic Conditions: June 9-12, 2009, Luleå, Sweden, 2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The potential for establishing wind power farms in the subarctic areas is high due to the combination of large available areas and few conflicting interests. In subarctic climate frost and thaw are major principal design aspects. In foundation work the major impact of frost action is at the outer peripheries of the foundation. Therefore most analysis work and prevention actions such as insulation around the foundation are concentrated to this part of the structure. The gravity foundations of wind power plants are often constructed as a reinforced concrete monolite. In the centre of the footing a steel cage is attached for anchoring the wind mill tower. This steel cage ends close to the sub-grade and can due to considerably higher thermal conductivity, compared to the concrete structure, transport a lot more heat. By FEM analysis, the frost penetration around, and under two typical wind-power foundations have been analyzed for different climate conditions in Sweden. In addition, different soil types have also been used. The result shows that the frost penetration in the centre of the foundation needs to be considered. Further it is shown that it is larger in the centre than compared to the periphery.

  • 153. Edeskär, Tommy
    et al.
    Helander, Andes
    Tyréns AB.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Grundläggning av vindkraftverk med hänsyn till tjäle2010Inngår i: Bygg & Teknik, ISSN 0281-658X, Vol. 102, nr 1, s. 68-73Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    På grund av den snabba utbyggnaden av vindkraftverk är erfarenheten från byggande i kallt klimat för dessa konstruktioner begränsad. Den forskning som bedrivs idag är mestadels inriktad mot vindkraftens miljöpåverkan samt frågor för att underlätta utbyggnaden och förbättra kostnadseffektiviteten, Statens energimyndighet (2008). Utbyggnad av vindkraftverk i extrema miljöer skapar nya frågor som bör utredas för att säkerställa verkens kvalitet i ett långtidsperspektiv. I denna artikel vill vi belysa frågan om tjäle och hur den är kopplad till grundläggning av vindkraftverk.

  • 154. Edeskär, Tommy
    et al.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Use of scrap tyres as insulation layer in road construction2007Inngår i: Proceedings of the 8th International Symposium on Cold region Development ISCORD 2007: September 25-27, 2007, Tampere, Finland, RIL - Finnish Association of Civil Engineers, 2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Used tyres are not allowed to be placed on landfills any more, but can be used as insulation materials with very good results. The present paper describes a study in which tyre shreds (50mm * 50 mm) were used as insulation material in a road construction. The tyre shreds had a thickness of 600 mm and were covered with 875 mm of road  superstructure. The effect of the layer on frost depth and frost heave was measured during three winters. As scrap tyres are a highly elastic the bearing capacity and Young's module were measure directly on the road by the use of a falling weight deflectometer. The potential environmental impact was also studied. The scrap tyres showed a very good insulation performance, mostly due to its high porosity. Effects of frost action were not visible or recorded. The studied construction had deformation pattern of the road surface was within acceptable limits. The environmental impact was studied before the pavement was placed at the top and therefore leakage could be detected.

  • 155.
    Eigenbrod, Dieter
    et al.
    Lakehead University, Thunder Bay, Ontario.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Measurements of pore water pressures at the interface of asphalt cement concrete pavement in soil1992Inngår i: Proc. Canadian Permafrost Conference, Edmonton, Sept. 1992: Canadian Geotechnical Society, Canadian Society for Civil Engineering , 1992, s. 44.1-44.10Konferansepaper (Fagfellevurdert)
  • 156.
    Eigenbrod, Dieter
    et al.
    Lakehead University, Thunder Bay, Ontario.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sheng, Daichao
    LTU.
    Measurements of pore pressures in freezing and thawing, soft fine-grained soils1992Inngår i: Proceedings, 46th Canadian Geotechnical Conference, Winnipeg, May 1992: Canadian Geotechnical Society, Canadian Society for Civil Engineering , 1992Konferansepaper (Fagfellevurdert)
  • 157.
    Eigenbrod, K. Dieter
    et al.
    Lakehead University, Thunder Bay, Ontario.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sheng, Daichao
    Luleå tekniska universitet.
    Pore-water pressures in freezing and thawing fine-grained soils1996Inngår i: Journal of cold regions engineering, ISSN 0887-381X, E-ISSN 1943-5495, Vol. 10, nr 2, s. 77-92Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Laboratory freezing tests were performed on laterally confined samples of lightly overconsolidated fine-grained soil exposed to one-dimensional freezing at a constant temperature gradient. Pore-water pressures and temperatures were measured at the perimeter of the specimens at various points along their height during freezing and thawing. Vertical heave and water inflow and outflow were also recorded in the sample. X-ray pictures were taken in order to correlate ice lens formation to the measured data. Of particular interest were occurrences of high pore-water pressures shortly after the freezing front had stabilized. Pore-water pressure peaks coincided typically with temperature peaks. Maximum negative pore-water pressures measured during freezing can be correlated to the compression observed in soft clay specimens subsequent to freezing and thawing, which is often called freeze-thaw consolidation. During early freezing, no heave was indicated in soft clay specimens even though numerous ice lenses had formed. No freeze-thaw-consolidation was recorded for stiff clay specimens with initial water contents near the plastic limit.

  • 158.
    Elfgren, Lennart
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand.
    Bernander, Stig
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand.
    Knutsson, Sven ()
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Response to and Comments on “Geotechnical Peer Review of Dr. S. Bernander’s Reports and Analysis of the North Spur”2018Rapport (Annet vitenskapelig)
    Abstract [en]

    The concerns regarding the stability of the North Spur can be summarized in three points:

    (1) None of the most critical inclined failure surfaces have been studied by Muskrat Falls Corporation. These failure surfaces may be initiated on the upstream side of the dam containment. Here the effects of the deformations, caused by the pressure of the rising water level, have to be resisted by the metastable soil layers in the North Spur. A local failure may occur progressing downwards towards the downstream side of the Spur. A catastrophic dam breach would follow. The GPRP further categorically overlooks the fact that horizontal failure planes cannot possibly represent the highest risk of instability irrespective of whether the analysis is based on the Limit Equilibrium Mode (LEM) or on the Progressive Failure Mode.

    (2) The stress/strain deformation properties of the porous soils in the North Spur have not been made available. Only strength properties, related to fully drained conditions, have been given. How stresses relate to simultaneous deformations under undrained (or partially undrained) conditions have not been defined in any way. Such relationships are crucially essential for any up-to-date analysis of slope stability.

    (3) A high risk of North Spur instability has been found related to impoundment.  A series of investigatory calculations have been made, based on deformation properties from similar landslides and on a wide variety of assumed input data for possible critical failure surfaces. The results of these analyses indicated a safety factor far below 1.

    The peer review does not address the above three points. It gives a good view of the general conditions but also contains misconceptions, erroneous considerations and refutable comments indicating that the earlier reports by Bernander have not been fully understood by the panel members.

    As no up-to-date analysis of the stability of the North Spur has been provided, our conclusion is that an independent group of experts, appointed by government, should be entrusted with this important task.

  • 159.
    Elias, Issa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Area-Storage Capacity curves for Mosul Dam, Iraq Using Empirical and Semi-Empirical Approaches2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The storage capacity of reservoirs is gradually depleted due to sediment accumulation that causes changes in the area-storage capacity curves (ASC). These curves are important for planners, designers and operators of dams. Many empirical and semi-empirical approaches have been suggested for establishing and predicting these curves. In this study four empirical and semi-empirical methods were evaluated and used to determine the ASC curves for Mosul dam reservoir (MDR), which is the biggest hydraulic structure on the River Tigris in northern Iraq. MDR started operating in 1986 with a storage capacity of 11.11 km3 and a water surface area 380 km2 at normal operation stage (330 m a.s.l.). The results obtained from these methods were evaluated using observed bathymetric survey data that had been collected in 2011 after 25 years of the operation of the dam. The evaluation results showed three methods presented more accurate results for estimating water depth or sedimentation depth at dam site with percentage error about 1.06% to 3.295%.

  • 160.
    Elias, Issa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi. Department of Dams and Water Resources Engineering, University of Mosul, Iraq.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sherwany, Govand
    Ministry of Higher Education and Scientific Research, Kurdistan Region.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Evaluation and modification of some empirical and semi-empirical approaches for prediction of area-storage capacity curves in reservoirs of dams2017Inngår i: International Journal of Sediment Research, ISSN 1001-6279, Vol. 32, nr 1, s. 127-135Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The storage capacity of reservoirs is gradually reduced due to sediment accumulation that causes changes in the area-storage capacity (ASC) curves. Establishing these curves and predicting their future change is an important issue for planners, designers and operators of dams. Many empirical and semi-empirical approaches have been suggested for establishing and predicting the future changes for these curves. In this study four empirical and semi-empirical methods were evaluated and three of them were modified to be used for the prediction of changes in the ASC curves due to sedimentation, based on the existing sedimentation survey data for 11 reservoirs in the USA. For evaluation, these approaches were reviewed and used to determine sedimentation depth and establishing the ASC curves for the Mosul dam reservoir (MDR), which is the biggest hydraulic structure on the River Tigris in northern Iraq. MDR started operating in 1986 with a storage capacity of 11.11 km3 and a water surface area 380 km2 at normal operation stage (330 m a.s.l.). The results obtained from these methods were evaluated using observed bathymetric survey data that had been collected in 2011 after 25 years of the operation of the dam. The evaluation results showed three methods had presented more accurate results for estimating water depth or sedimentation depth at dam site with percentage error about 1.06–3.30%. Whilst for establishing ASC curves, one method presented good agreement result with survey data. Furthermore, ASC and sedimentation depths at dam site of MDR for periods 50, 75, 100 and 125 years were estimated using the modified approaches and the area reduction method. The results of the modified methods provided reasonable agreement when compared with the area reduction method proposed by the U.S. Bureau of Reclamation and the agreement became better with an increase in time period.

  • 161.
    Emborg, Mats
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Jonasson, Jan-Erik
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Långtidsstabilitet till följd av frysning och tining av betong och bentonit vid förvaring av låg- och medelaktivt kärnavfall i SFR 12007Rapport (Annet vitenskapelig)
  • 162.
    Ezz-Aldeen, Mohammad
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Application of SWAT Model to Estimate the Runoff and Sediment Load from the Right Bank Valleys of Mosul Dam Reservoir2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mosul Dam is the biggest hydraulic structure on the River Tigris in Iraq with 11.11 billion m3 storage capacity. The dam is a multipurpose project. It is used to store the water for irrigation, hydropower generation, and flood control. As in other dams in the world, this dam also have sedimentation problem. Sediment accumulation in its reservoir can effect the dam operation (pumping station, hydropower plants, and bottom outlets) and it will definitely shorten the life span of the dam. In this study, the Soil and Water Assessment Tool (SWAT) under Geographical Information System (GIS) was applied to simulate the yearly surface runoff and sediment load for the main three valleys on the right bank of Mosul Dam Reservoir. The simulation considered for the twenty one years begin from the dam operation in 1988 to 2008. The resultant values of the average annual sediment load are 35.6*103, 4.9*103, and 2.2*103 ton, while the average values of sediment concentration are 1.73, 1.65, and 2.73 kg/m3 for the considered valleys one, two and three respectively. This implies that significant sediment load enters the reservoir from these valleys. To minimize the sediment load entering the reservoir, a check dams is to be constructed in suitable sites especially for valley one. The check dam can store the runoff water and trap the sediment load, and then the flow can be released to the reservoir.

  • 163.
    Ezz-Aldeen, Mohammad
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Estimating life span of rainwater harvesting reservoirs in Sinjar area, Iraq2016Inngår i: Journal of Environmental Hydrology, ISSN 1058-3912, E-ISSN 1996-7918, Vol. 24, s. 1-10, artikkel-id 9Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Due to water shortage in different places in Iraq especially for areas far away from main river flows (Tigris and Euphrates Rivers), rainwater harvesting reservoirs were suggested previously to store runoff water for different water supply purposes. In this study, the Soil and Water Assessment Tool (SWAT) was applied to estimate the sediment load yields from each watershed of a selected reservoir to estimate probable life based on resultant sediment load and trap efficiency. The results indicates that the annual sediment load varied from 40*103 to 4.4*103 ton depending on watershed area and other effective properties, while the sediment yield per unit area were ranged between 9.5 to 20 ton/km2. The estimated trap efficiency based on annual inflow and reservoir storage capacity were varied from a minimum of 96.5 to 100% due to high reservoir capacity in comparison to annual inflow. The resultant probable life of the reservoirs was greater than 100 years, indicating that the reservoir can economically accepted.

  • 164.
    Ezz-Aldeen, Mohammad
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Runoff and sediment load from the right bank valleys of Mosul dam reservoir2012Inngår i: Journal of Civil Engineering and Architecture, ISSN 1934-7359, E-ISSN 1934-7367, Vol. 6, nr 10, s. 1414-1419Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mosul Dam is a Multipurpose Project on the River Tigris in Iraq with 11.11 billion m3 storage capacity.. It is used to store the water for irrigation, hydropower generation, and flood control. As in other dams in the world, this dam also have sedimentation problem. Sediment accumulation in its reservoir can effect the dam operation (pumping station, hydropower plants, and bottom outlets) and it will definitely shorten the life span of the dam. In this study, the SWAT (soil and water assessment tool) under GIS (Geographical Information System) was applied to simulate the yearly surface runoff and sediment load for the main three valleys on the right bank of Mosul Dam Reservoir. The simulation considered for the twenty one years begin from the dam operation in 1988 to 2008. The resultant values of the average annual sediment load are 35.6x103, 4.9x103, and 2.2x103 ton, while the average values of sediment concentration are 1.73, 1.65, and 2.73 kg/m3 for the considered valleys one, two and three respectively. This implies that significant sediment load enters the reservoir from these valleys. To minimize the sediment load entering the reservoir, a check dam is to be constructed in suitable sites especially for valley one. The check dam can store the runoff water and trap the sediment load, and then the flow can be released to the reservoir.

  • 165.
    Ezz-Aldeen, Mohammad
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sediment delivery from right bank valleys to Mosul reservoir, Iraq2012Inngår i: Journal of Ecology and Environmental Sciences / Bioinfo publications, ISSN 0976-9900, E-ISSN 0976-9919, Vol. 3, nr 1, s. 50-53Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mosul dam reservoir is the biggest reservoir on the River Tigris with 11.11 billion m3 storage capacity located at the northern part of Iraq. The dam is used for irrigation, hydropower generationand flood control. Siltation of the reservoir and sediment delivery from the valleys to the reservoir was not measured since the operation of the dam in 1988. Sediment accumulation in its reservoir can effect the dam operation (pumping station, hydropower plantsand bottom outlets) and it will definitely shorten the life span of the dam. In this study, the Soil and Water Assessment Tool (SWAT) under Geographical Information System (GIS) was applied to simulate the yearly surface runoff and sediment load for the main three valleys on the right bank of Mosul am Reservoir for the period 1988-2008. The resultant values of the average annual sediment load are 42.7*103, ton. This implies that significant sediment load enters the reservoir from these valleys. Sediment accumulation can effect the dam operation (pumping station, hydropower plants and bottom outlets) and it will definitely shorten the life span of the dam. To minimize sediment effect, check dams are to be constructed specially on the first valley.

  • 166.
    Ezz-Aldeen, Mohammad
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hassan, Rebwar
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Ali, Ammar
    Department of Water Resources Engineering, Baghdad Universi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Watershed Sediment and Its Effect on Storage Capacity: Case Study of Dokan Dam Reservoir2018Inngår i: Water, ISSN 2073-4441, E-ISSN 2073-4441, Vol. 10, nr 7, artikkel-id 858Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dokan is a multipurpose dam located on the Lesser Zab River in the Iraq/Kurdistan region. The dam has operated since 1959, and it drains an area of 11,690 km2. All reservoirs in the world suffer from sediment deposition. It is one of the main problems for reservoir life sustainability. Sustainable reservoir sediment-management practices enable the reservoir to function for a longer period of time by reducing reservoir sedimentation. This study aims to assess the annual runoff and sediment loads of the Dokan Dam watershed using the soil and water assessment tool (SWAT) model to evaluate the relative contributions in comparison with the total values delivered from both watershed and Lesser Zab River and to identify the basins with a high sediment load per unit area. These help in the process of developing a plan and strategy to manage sediment inflow and deposition. The SUFI-2 program was applied for a model calibrated based on the available field measurements of the adjacent Derbendekhan Dam watershed, which has similar geological formations, characteristics and weather. For the calibration period (1961–1968), the considered statistical criteria of determination coefficients and Nash–Sutcliffe model efficiency were 0.75 and 0.64 for runoff while the coefficients were 0.65 and 0.63 for sediment load, respectively. The regionalization technique for parameter transformation from Derbendekhan to Dokan watershed was applied. Furthermore, the model was validated based on transformed parameters and the available observed flow at the Dokan watershed for the period (1961–1964); they gave reasonable results for the determination coefficients and Nash–Sutcliffe model efficiency, which were 0.68 and 0.64, respectively. The results of SWAT project simulation for Dokan watershed for the period (1959–2014) indicated that the average annual runoff volume which entered the reservoir was about 2100 million cubic meters (MCM). The total sediment delivered to the reservoir was about 72 MCM over the 56 years of dam life, which is equivalent to 10% of the reservoir dead storage. Two regression formulas were presented to correlate the annual runoff volume and sediment load with annual rain depth for the studied area. In addition, a spatial distribution of average annual sediment load was constructed to identify the sub basin of the high contribution of sediment load.

  • 167.
    Fikrat, Hassan
    et al.
    University of Baghdad.
    Salman, Jasim
    Babylon University.
    Al-Azawey, Atheer
    Babylon University.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Quatlity, quantity and origin of polycyclic aromatic hydrocarbons (PAHs) in lotic ecosystem of AL-Hilla river, Iraq2014Inngår i: Journal of Civil Engineering and Architecture, ISSN 1934-7359, E-ISSN 1934-7367, Vol. 8, nr 8, s. 1026-1038Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The quality, quantity and the origin of Poly Aromatic Hydrocarbon (PAHs) were studied in the water and sediment of Al-Hilla river (branch of the Euphrates river inside Iraq). In addition, some physical and chemical properties were studied at six sites along the studied area, for the period March, 2010 to February, 2011. Sixteen Polycyclic Aromatic Hydrocarbons (PAHs) that are listed by USEPA as priority pollutants ( Naphthalene, Acenaphthylene, Acenaphthene, Fluorene, Phenanthrene, Anthracene, Fluoranthene, Pyrene, Benzo(a)Anthracene, Chrysene, Benzo(b) Fluoranthene, Benzo(k) Fluoranthene, Benzo(a) Pyrene, Dibenzo(a,h) Anthracene, Benzo(ghi) Perylene and Indeno (1,2,3-cd) Pyrene) were detected in Al-Hilla river. High concentrations of PAHs were detected in the sediment relative to that within the water. The present study revealed that the origin of PAHs in water and sediment might be the Pyrogenic origin.

  • 168.
    Forsberg, Thomas
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Yang, Ting
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Borehole seals of expandable clay with desired water content by use of “dry water”2017Inngår i: Proceedings of the 19th International Conference on Soil Mechanics and Geotechnical Engineering, Seoul 2017, 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Dense clay can be used for sealing of boreholes and isolation of waste containers. Expansion of the clay to fill the space between containers and confining rock takes place by uptake of water of the clay, which thereby provides effective isolation. The issue is to prepare clay inserts with properly selected water content. The paper describes preparation of clay seals by mixing air-dry clay powder with nanoparticles of water droplets coated with very thin shells of a hydrophobic silicious substance (“dry water”). It behaves as dry powder and is easily mixed with dry clay. On compaction to the desired density the shells break into microscopic fragments while water becomes homogeneously distributed in the mass. Laboratory tests verify that the properties of clay prepared in this way are the same, or better, than of commonly saturated clay.

  • 169.
    Forsberg, Thomas
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och brand.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Yang, Ting
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Borehole seals of expandable clay with desired water content by use of “dry water”2017Inngår i: Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dense clay can be used for sealing of boreholes. Keeping the clay confined in perforated tubes it can be inserted in boreholes of nearly any length and diameter. Expansion of the clay to fill the borehole takes place by uptake of water and migration of clay through the perforation. The clay thereby exerts a swelling pressure on the confining rock causing effective sealing. For shallow boreholes to be sealed a very low initial degree of water saturation of the clay may be valuable since this makes the clay expand and seal the hole quickly, but for certain cases the clay should have a higher degree of water saturation. This can be required for moderating the rate of clay densification that may otherwise give too high wall friction for placement in very long holes. Sealing of very deep holes and holes containing highly radioactive waste makes temperature important: the heat-induced expansion of initially fully saturated clay can fracture the confining rock. The issue is therefore to prepare the clay inserts withproperly selected water content. The paper describes preparation of clay seals by mixing air-dry clay powder with nanoparticles of water droplets coated with very thin shells of a hydrophobic silicious substance (“dry water”). It behaves as dry powder and is easily mixed with dry clay. On compaction to the desired density the shells break into aggregates of minute fragments while water becomes homogeneously distributed in the mass. Laboratory and bench-scale testing verify that the properties of clay prepared in this way are the same as of clay saturated by sorbing water through a filter, a process that can take hundreds of years for big samples. Keywords:borehole sealing, clay blocks, degree of saturation, density, “dry water”, water content1. IntroductionSeveral concepts for sealing of boreholes and disposal of radioactive waste make use of dense

  • 170.
    Forsberg, Thomas
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Yang, Ting
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Clay/water mixture by use of nano-sized water droplets "dry-water"2017Inngår i: ICSMGE 2017: 19th International Conference on Soil Mechanics and Geotechnical Engineering, 19th ICSMGE Secretariat , 2017, s. 2367-2370Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Dense clay can be used for sealing of boreholes and isolation of waste containers. Expansion of the clay to fill the space between containers and confining rock takes place by uptake of water of the clay, which thereby provides effective isolation. The issue is to prepare clay inserts with properly selected water content. The paper describes preparation of clay seals by mixing air-dry clay powder with nanoparticles of water droplets coated with very thin shells of a hydrophobic silicious substance ("dry water"). It behaves as dry powder and is easily mixed with dry clay. On compaction to the desired density the shells break into microscopic fragments while water becomes homogeneously distributed in the mass. Laboratory tests verify that the properties of clay prepared in this way are the same, or better, than of commonly saturated clay. © 2017 19th ICSMGE Secretariat. All rights reserved.

  • 171. Forsström, Anna
    et al.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Dra nytta av vintern och skapa användbar permafrost2001Inngår i: Bygg & Teknik, ISSN 0281-658X, Vol. 93, nr 1, s. 61-64Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 172. Forsström, Anna
    et al.
    Long, Erwin L.
    Arctic Foundations Inc., Anchorage.
    Zarling, John P.
    University of Alaska, Fairbanks.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Thermosyphon cooling of Chena Hot Springs Road2002Inngår i: Cold Regions Engineering Cold Regions Impacts on Transportation and Infrastructure.: Proceedings of the International Conference / [ed] Kelly S. Merrill, New York: American Society of Civil Engineers (ASCE), 2002, s. 645-655Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Thermosyphons have been used to maintain permafrost below structures for over forty years. The Chena Hot Springs Road Test Section became operational during the fall of 1998 and includes three test sections underlain with different types of thermosyphons plus a control section. The test section overlays high-moisture-content permafrost. After two seasons, the thaw depth decreased and the freezing depth increased in all sections, including the control. Pavement edge temperatures showed a decided cooling trend which was slight for the control, more pronounced for the UAF/CRREL units and AFI flat loop evaporator units, and highest for the AFI buried units section. The centerline thermal conditions relate to the condenser size, while the pavement edge or shoulder conditions relate to the type of installation. During the winter season, the AFI buried condenser thermosyphons show surface warming and sublimation of snow closer to that of the control section, while the other two test sections are colder at the surface during the winter season.

  • 173.
    Gustafsson, Gustaf
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Häggblad, Hans-Åke
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Material- och solidmekanik.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Experimental characterization of constitutive data of iron ore pellets2009Inngår i: Powder Technology, ISSN 0032-5910, E-ISSN 1873-328X, Vol. 194, nr 1-2, s. 67-74Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For trustworthy numerical simulations of iron ore pellets flow, knowledge about the mechanical properties of pellets is needed. In this work, an elastic-plastic continuum material model for blast furnace iron ore pellets is worked out from an experimental data. The equipment used is a Norwegian simple shear apparatus, designed for compression and shear test of granular material with a grain size less than 100 mm. It consists of a cylindrical cell filled with pellets surrounded by a rubber membrane and a rigid top and bottom. Two types of tests are performed. One test is pure compression and unloading and the second is shearing at different stress levels. Evaluation of these tests is performed and the elastic-plastic behaviour of iron ore pellets is characterized. Determined constitutive data are two elastic parameters and a yield function. The presented material model captures the major characteristics of the pellets even though it is too simple to completely capture the complex behaviour shown in the experiments.

  • 174.
    Gustafsson, L.
    et al.
    Luleå tekniska universitet.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Image analysis method for studying movements in granular and solid bodies1994Inngår i: ASTM geotechnical testing journal, ISSN 0149-6115, E-ISSN 1945-7545, Vol. 17, nr 1, s. 95-100Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A method based on image analysis of video recordings is presented for studying and measuring movements in granular materials. The method is easy to use, does not require any tracers, and makes extensive experiments feasible. Calibration tests show good repeatability. Measurements are presented of movements in a sand mass into which a piston is driven. The method is also useful for studying the deformation of solid bodies. The deformation of undrained clay specimens subjected to uniaxial forces is demonstrated using the proposed method.

  • 175.
    Hassan, Rebwar
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Ali, Ammar A.
    College of Engineering, University of Baghdad, Baghdad, Iraq.
    Ali, Salahalddin S.
    Department of Geology, University of Sulaimani, Sulaymaniyah, Iraq.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Bathymetry and siltation rate for Dokan Reservoir, Iraq2017Inngår i: Lakes & Reservoirs: Research and Management, ISSN 1320-5331, E-ISSN 1440-1770, Vol. 22, nr 2, s. 179-189Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Dokan Reservoir dam is a concrete cylindrical arch with gravity abutments, located on the Lesser Zab River about 60 km from the city of Sulaimani in north-eastern Iraq. A bathymetric survey was conducted in November 2014 for a period of 10 days, using an echo sounder of 200-kHz single beam. The survey results indicated an annual average sediment deposition of 3.8 million m3. Thirty-two sediment samples were collected from the reservoir bed. The ratio of gravel, sand, silt and clay was 15:14:48:23, respectively. The reservoir bed is covered mainly with silt. The sediments are composed of silty clay (77.6%), silty sandy clay (10%), sandy gravely silty clay (1.2%) and gravely sandy silty clay (1%).

  • 176.
    Hassan, Rebwar
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Ali, Salahaddin S.
    Department of Geology, University of Sulaimani, Sulaymaniyah, Iraq.
    Ali, Ammar A.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Abdullah, Twana
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Dukan Dam Reservoir Bed Sediment, Kurdistan Region, Iraq2016Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 8, nr 9, s. 582-596Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Dukan Dam Reservoir (DDR) in the Kurdistan Region of Iraq has been studiedto determine the characteristics and nature of the reservoir and the deposited sedimentson its bottom surface. This study was achieved by doing a field survey andgrain size analyses of the collected sediment samples at 32 locations representing thewhole reservoir area that had been created when the Lesser Zab River was dammedin 1959. The Dukan Dam, which is a multi-purpose concrete arch dam, was built onthe Lesser Zab River for controlling its flood during high rainfall seasons, irrigationand power generation. The catchment area is 11,690 km2. The surface area of the reservoiris 270 square kilometers and the volume is 6.870 × 106 m3 at normal operationlevel (El. 511.00 m. a.s.l.). The minimum drawdown level is at elevation 469 mabove sea level (a.s.l.). The live storage is 6.14 × 106 m3 while the remainder is deadstorage. The reservoir has a surface area that reaches 270 square kilometers and iscomposed of two sub-reservoirs connected by a narrow channel that has a length of 5kilometers. The relatively bigger reservoir is located in the north and has a triangularshape with a surface area approximately 250 square kilometers. The smaller sub-reservoiris located down south where the dam exists and it has irregular rectangularshape. Thirty-two sediment samples were collected from the bottom of Dukan reservoir.The bed of the reservoir is mainly composed of 15% gravel, 14% sand, 48%silt and 23% clay respectively. Most of the sediments are very fine grained, verypoorly sorted, strongly coarse skewed and mesokurtic.

  • 177.
    Hassellund, Lovisa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Roger
    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.
    Numerical analysis of an upstream tailings dam2016Inngår i: Proceedings of Nordic Conference on Soil Mechanics and Geotechnical NGM: Reykjavik, Iceland 25th – 28th of May 2016, 2016, s. 727-736Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a case study of how the finite element methodcan be utilized to analyze stability of upstream tailings dams. Upstream tailings dams are usually raised gradually and the increased load normallyinfluencesthe stability in an unfavorableway;the load generatesexcess pore water pressures and reduced stability. In this study, an upstream tailings dam in Northern Sweden wasnumericallysimulated with the finite element software PLAXIS 2D in order to assess the stability of the dam. Upstream tailings dams are sensitive to high raising rates since initiated excess pore water pressures might not have time to dissipate. Stability analysis of a tailings damis an application that is very suitable to carry out using finite element software; once a finite element model of thecomplex geometry of adam has been established, it is easy to stepwiseadd new soil volumes, associated with each new raising, to the model.In this case study, it was found that strengthening actions were needed in order to maintain a stable structure. Rockfill berms weregradually added onthe downstream slope of the model to obtaina factor of safety above a recommended value. The volumes of rockfill needed for the berms wereminimized by numerical optimization to reduce costs. The stability betweenthe years2024 and2034 was analyzed; with an annual deposition cycle. The performednumerical studyresulted in a future plan for placement of rockfill berms to establishsufficient stability ofthe tailings dam. It was found that the volume of rockfill in the berms needed, varied during the years studied. Numerical modeling, as presented in this paper, is a useful tool for the dam owner to plan and design for future raisings of a tailings dam

  • 178.
    Hassellund, Lovisa
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Roger
    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.
    Numerical Simulations of Stability of a Gradually Raised Upstream Tailings Dam in Northern Sweden2016Inngår i: The Electronic journal of geotechnical engineering, ISSN 1089-3032, E-ISSN 1089-3032, Vol. 21, nr 13, s. 4699-4720Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents a case study where numerical modeling, with the finite element method, has been utilized to assess future stability of a tailings dam in Northern Sweden. The finite element software PLAXIS was utilized to simulate future dike raisings for the years 2024 to 2034. The simulations were conducted by computing each dike raising, the subsequent consolidation of the soil and the stability of the dam during the process. The factors of safety directly after each dike raising resulted in values continuously below a recommended value of 1.5. To increase the dam stability, rockfill berms were stepwise added on the downstream slope of the dam. An optimization technique was applied to place as small volumes of rockfill as possible in the berms at the most suitable locations on the downstream slope. By adding various volumes of rockfill in the berms each year, sufficient stability of the dam was obtained in the simulations. The excess pore water pressures increased annually in the simulations. It was shown that the excess pore water pressures did not totally dissipate before the following dike was constructed. The highest excess pore water pressures were located deep in the impoundment and did not have large effects on the dam stability.

  • 179.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Enhancement of Workability of Cement-Poor Concrete by Optimizing Paste Content2014Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 6, nr 13, s. 869-876, artikkel-id 4Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study describes the performance of concrete in fresh state, intended for sealing deep boreholes in the host rock of radioactive repositories. Set of different paste volumes, combinations of water-to-powder ratios and fine aggregate contents have been performed within the frame of this study. The main objective was to search for tendencies, logical connections and phenomena that occur for different combination of materials regarding the fluidity and segregation and mainly the effect from the (paste) or fine aggregate content. It shall be pointed out that this investigation is a suggestion on how concrete can be optimized using two simple test methods based on changing the paste content. The results highlighted the importance of having sufficient amounts of filler and cement paste for separate and carry larger particles, which gives the concrete good workability and fluidity at casting. It was concluded that the slump behaviors can be optimized based on the adjustments of the superplastisizer dosage.

  • 180.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jonasson, Jan-Erik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Rheological properties of low pH cement-palygorskite injection grout2013Inngår i: Journal of Advanced Science and Engineering Research, ISSN 2231-8844, Vol. 3, nr 3, s. 167-192Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The rheological properties of cementitious materials containing fine particles, such as mineral admixture were investigated using a Viso Star-L rheometer with cylindrical spindles. Selected features of the behavior of these materials are evaluated from a rheological perspective through literatures results for the past 30 years. One of the important factors that governs the ability of grout to penetrate fractures, channels and porous material is the rheology. The mineral admixture was clay palygorskite which can be used for early gelation because of its thixotropic properties as well as the powder quartz used as aggregate. The cementitious materials were designed and three recipes (MPG1, MPG2 and MPG3) were examined in this research by changing the mix proportions of the mineral admixture palygorskite and water content. For ensuring the accuracy of rheological measurement for the candidate’s grouts, necessary verification was been evaluated such as, influence of mixing time, stability and “time effect” to the accuracy of viscosity measurement, and yield stress as well as the physical properties at 3, 7 and 28 days. The results showed that grouts recipes with quartzite aggregate of different granulometry, are chemically compatible and fulfill the requirement of containing no organic matter. Candidate’s grouts found to satisfy the stable sedimentation criteria with sedimentation rates less than 5% after 2 hours. Furthermore, it was found that the grout recipe 3 followed by 1 showed lower yield stress and plastic viscosity which are (0.1 Pa and 0.269 Pas) and (0.288 Pa and 0.531 Pas) respectively.

  • 181.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Gburi, Majid
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jonasson, Jan-Erik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Design of concrete mixes by systematic steps and ANN2012Inngår i: Journal of Advanced Science and Engineering Research, ISSN 2231-8844, Vol. 2, nr 4, s. 232-251Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The current research caters for the possibility of arriving at a system for designing concrete mixeseasily using available materials locally by specified wide ranges of pre-requisites of three mainprescribed properties to cover a good variety of practical mixes, which are water, water-cement ratioand total aggregate-cement ratio. Using these three properties, a tri-linear form was constructed bygraphical technique manner based on absolute volume approach. This approach defines as asummation of absolute volume for each of these three materials individually water, cement andaggregate should be equal to the absolute volume of whole concrete mixture based on thesealtogether. A quad-form area which includes a wide range of mixes can be formed from thisrepresentation. This area should achieve all the prescribed properties aforementioned. Artificial neuralnetwork concept used in this study also to build easily and quickly system which can be translatedinto Excel sheet. This system predict proportions of concrete mixture and the compressive strengthusing the results designed by the quad-form area method in addition to the data from literature around500 mixes based on local materials used in Iraq. Six input parameters (water to cement ratio, theslump, % of fine to total aggregate content, maximum aggregate size, fineness modulus of fineaggregate and the compressive strength) were used in this system to get the outputs. In addition, nineinput parameters ((water, cement, sand and gravel contents) and the properties of the mix (Finenessmodulus, W/C ratio, the slump, % of fine to total aggregate and the M.A.S)) were used as basis ofcompressive strength model. The algorithm of this system aimed to reduce the high number of trailmixes error as well as saving the labors, cost and time. Results indicated that the concrete mix designand the compressive strength model can be predicted accurately by using graphical perspective andthe ANN approach.

  • 182.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Emborg, Mats
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Packing theory for natural and crushed aggregate to obtain the best mix of aggregate: research and development2012Inngår i: Proceedings of World Academy of Science, Engineering and Technology, ISSN 2010-376X, E-ISSN 2070-3740, Vol. 67, s. 819-825Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Concrete performance is strongly affected by the particle packing degree since it determines the distribution of the cementitious component and the interaction of mineral particles. By using packing theory designers will be able to select optimal aggregate materials for preparing concrete with low cement content, which is beneficial from the point of cost. Optimum particle packing implies minimizing porosity and thereby reducing the amount of cement paste needed to fill the voids between the aggregate particles, taking also the rheology of the concrete into consideration. For reaching good fluidity superplasticizers are required. The results from pilot tests at Luleå University of Technology (LTU) show various forms of the proposed theoretical models, and the empirical approach taken in the study seems to provide a safer basis for developing new, improved packing models.

  • 183.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Optimization of concrete by minimizing void volume in aggregate mixture system2012Inngår i: Journal of Advanced Science and Engineering Research, ISSN 2231-8844, Vol. 2, nr 3, s. 208-222Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The behavior of concrete is affected by the size, distribution of the voids, the porosity and of the granulometry of the aggregate mixture. As a consequence it necessary for engineers to consider in detail particle packing concepts and their influence on the physical performance of concrete. The present study included determination of the fineness modulus, cement paste volume based on slump test and the properties of fresh and hardened concrete. It also comprised a study of the applicability of two theoretical models Toufar’s and 4C-packing program for selecting suitable relative amounts of the concrete constituents, for obtaining a minimum void ratio. Comparison of the results was made from using these theoretical models literature-derived experimental data. The models gave similar results and suggest similar combinations of materials to give minimum void ratio. Optimization of the composition of the aggregate material in concrete is beneficial with respect to economy (low cement content), strength and durability. It was noted that minimizing the void ratio (V) tends to raise the stiffness and that the compressive strength (푓푐′) is closely related also to their molding (R) and fineness modules (FM). It was found that the compressive strength can be predicted by applying the formula;푓푐′=−2.1−63.8 푉+0.150 푅+10.4 퐹푀; R2=0.94, and two other relationships related to slump data and cement content.

  • 184.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Emborg, Mats
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Nilsson, Martin
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Alireza, Pourbakhtiar
    Talc-based concrete for sealing borehole optimized by using particle packing theory2013Inngår i: Journal of Civil Engineering and Architecture, ISSN 1934-7359, E-ISSN 1934-7367, Vol. 7, nr 4, s. 440-455Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The paper describes assessment of the performance of cement-poor concreteson the basis of packing theory. The concretes are intended for sealing segments of deep boreholes and have a small amount of cement for minimizing the mutual chemical impact on the contacting clay seals. The composition is examined by application of packing theory with respect to the cement/aggregate ratio and the gradation of the aggregate material which is crushed quartzite for providing high internal friction after maturation, as well as to talc added for fluidity and to the small amount of cement. Low porosity and micro-structural stability must be guaranteed for very long periods of time. The study exemplifies how packing theory assist designers in selecting optimal proportions of the various components. Optimum particle packing implies minimizing the porosity and thereby reducing the amount of cement paste needed to fill the voids between the aggregate particles. The use of talc as inorganic super-plasticizer since ordinary organic additives for reaching high fluidity at casting are undesirable, and since talc reacts with cement and provides high strength in along-term perspective.

  • 185.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jonasson, Jan-Erik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Emborg, Mats
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Pourbakhtiar, Alireza
    Proportioning of cement-based grout for sealing fractured rock-use of packing models2013Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 5, nr 10, s. 765-774Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Fractured, very permeable rock hosting repositories for radioactive waste will require grouting. New grout types of possible use where long-term performance is needed should have a small amount of cement for minimizing the increase in porosity that will follow from the ultimate dissolution and erosion of this component. They have to be low-viscous and gain strength early after injection and packing theory can assist designers in selecting suitable proportions of various grout components. Optimum particle packing means that the porosity is at minimum and that the amount of cement paste needed to fill the voids between aggregate particles is very small. Low porosity and microstructural stability must be guaranteed for long periods of time. Organic additives for reaching high fluidity cannot be used since they can give off colloids that carry released radionuclides and talc can be an alternative superplasticizer. Low-pH cement reacts with talc to give high strength with time while Portland cement gives early but limited strengthening. The clay mineral palygorskite can be used for early gelation because of its thixotropic properties. Once forced into the rock fractures or channels in soil it stiffens and serves as a filter that prevents fine particles to migrate through it be lost. However, its hydrophilic potential is too high to give the grout a high density and high strength. According to the experiments carried out most of the investigated grouts are injectable in fractures with apertures down to 100 μm.

  • 186.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Study of cement-grout penetration into fractures under static and oscillatory conditions2015Inngår i: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 45, s. 10-19Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Grouting of the rock surrounding high-level waste (HLW) can serve to minimize groundwater flow around it and thereby to retard erosion of waste-embedding clay (buffer) and transport of possibly released radionuclides. Earlier attempts have shown the efficiency of superimposing the injection pressure with oscillations for bringing cement-rich grouts into narrow fractures using organic superplasticizers. However, these are short-lived and can produce radionuclide-bearing organic colloids, and should be replaced by inorganic agents. Portland cement in grouts is not long lived and low-pH cements are preferable as is also reduction of the cement content to an absolute minimum. The present study describes the composition and performance of candidate grouts in laboratory experiments with injection into plane-parallel slots with different aperture. The study included development of a simple and quick method for estimating the viscosity on the construction site for adapting the grout recipe to the injectability of the rock. A simple theoretical model for predicting grout penetration gives fair agreement with laboratory data. The longevity of the grout under various conditions is believed to be sufficient for use in HLW repositories implying waste placement in very deep holes

  • 187.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hellström, J. Gunnar I.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Rheological Properties of Cement-Based Grouts Determined by Different Techniques2014Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 6, nr 5, s. 217-229Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The rheological properties of cement-based grouts containing talc or palygorskite were investigated for optimizing fluidity and quick strengthening at injection. The fluidity controls the ability of grout to penetrate fractures and can be determined by pipe flow tests, Marsh funnel tests, mini-slump cone tests and rheometer tests. The grouts were 1) Talc for fluidity and strength by reacting with cement, 2) Palygorskite (attapulgite) for early gelation by being thixotropic, and 3) Powdered quartz for chemical integrity. The freshly prepared grouts behaved as Bingham fluids with viscosities from 0.151 to 0.464 Pas and yield stresses 5.2 Pa to 36.7 Pa. Statistical analysis of the flow test data converted Marsh flow time into viscosity. The pipe flow tests gave 26.5% higher values than the viscometer for grout with Portland cement and talc, and about 13.7% lower than the viscometer data for the grout with low-pH cement and talc. The big Marsh funnel gave valuesdiffering by 5.2% - 5.3% from those of the viscometer for grout with talc and Portland, and Merit 5000 cements. For grout with palygorskite the viscosity was at least twice that of the other grouts. Grout fluidity was positively affected by talc and negatively by palygorskite and early cement hydration

  • 188.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jonasson, Jan-Erik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Performance of Cement-poor Concrete with Different Superplasticizers2014Inngår i: International Journal of Research and Reviews in Applied Sciences, ISSN 2076-734X, E-ISSN 2076-7366, Vol. 18, nr 2, s. 163-172Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Concrete can be used for casting plugs in deep boreholes where fracture zones are intersected. They will be exposed to flowing groundwater and be in contact with very tight seals of smectite clay installed where the surrounding rock is tight. The cast concrete must be able to carry the clay segments placed over it after a few days. Its bearing capacity does not have to be very high after that since the clay soon adheres to the rock and carries itself. The concrete must be poor in cement for minimizing the risk of creation of voids caused by dissolution of the cement and it should have “inert” aggregate of quartz-rich material. Inorganic superplasticizers instead of conventional organic ones should be used for eliminating the risk of degradation and loss by formation of colloids that can carry radionuclides to the biosphere from holes bored in repository rock. The two concrete types discussed in the present study had Portland and Merit 5000 low pH cement as binders and crushed quartzite as aggregate. Talc mineral powder and ordinary organic Glenium 51 were used as superplasticizers for comparing their impact on the physical properties. The matrix of the cement-poor talc concrete gave ductile behaviour during initial hardening. The very dense matrix of either of the concretes would not lead to compression of the system even after complete loss of cement, which will happen over a longer period of time. The overall conclusion was that talc as superplasticizer and conditioner of the concrete can make the concrete sufficiently fluid for constructing seals at depth in boreholes, and react with cement to provide high strength with some delay. pH is much lower in Merit than in Portland concrete, which causes less impact on the clay seals. Portland concrete has five times higher strength than Merit concrete after a week but three times lower strength after 28 days.

  • 189. Hatem, Mohammed
    et al.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Warr, Laurence
    Greifswald University, Geographical & Geological Department, Germany.
    Hydrothermal alteration of clay and low pH concrete applicable to deep borehole disposal of high-level radioactive waste: A pilot study2016Inngår i: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 104, s. 1-8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the very deep borehole (VDH) concept for high level radioactive waste disposal, the combined usage of clay and concrete provides an attractive way of achieving both high strength and low permeability required for sealing the various sections of the hole. The concrete is required for mechanical stability where water-bearing fracture zones are intersected, whereas the clay effectively seals sections in stable rock masses. As both the clay and concrete may be exposed to temperatures in the range of 60–150 °C in various parts of the hole, there is a need to address the stability of these materials under thermally enhanced aqueous conditions. In this pilot study, a new type of organic-free, low pH concrete based on granulated blast furnace slag is tested, which is hardened and altered under hydrothermal conditions in the laboratory. The results presented show that both adequate compressive strength (up to ∼9 MPa) and low hydraulic conductivity (down to ∼5.6 × 10−10) is attained at elevated temperatures ranging up to 150 °C, indicating that clay-concrete sealing can be a successful method used to prevent radionuclides from migrating vertically up through the borehole repository.

  • 190.
    Hatem, Mohammed
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Byggkonstruktion och -produktion.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Warr, Laurence
    Institute of Geography and Geology, Ernst-Moritz-Arndt-University of Greifswald.
    Kasbohm, Jörn
    Institute of Geography and Geology, Ernst-Moritz-Arndt-University of Greifswald.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Interaction of clay and concrete relevant to the deep disposal of high-level radioactive waste2015Inngår i: Applied Clay Science, ISSN 0169-1317, E-ISSN 1872-9053, Vol. 118, s. 178-187Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A concept for the disposal of highly radioactive waste at depth in the Earth’s crust using very deep bore-holes requires that the upper 2 km’s of the 800 mm diameter, steeply drilled holes, be effectively sealed. This can be achieved by using dense smectitic clay where the rock is weakly fractured and strengthening with concrete when fracture zones are encountered. Earlier investigations have shown that chemical reactions between the clay and concrete can be expected both in the upper part where the temperature is lower than 90oC and in the deeper section where the temperature reaches up to 150oC. To study further this interaction, hydrothermal experiments were conducted using mixed-layer (illite/smectite) Holmehus clay and a low pH slag-based concrete placed in contact under isothermal conditions at 21°C, 100oC and 150oC for a period of 8 weeks. The sample sets, which consisted of two clay discs separated by concrete cast on the lower clay disc, were extracted in undisturbed form and exposed to uniaxial pressure for measuring the compressive strength at successively increasing pressures. Compression tests underenhanced thermal conditions led to strengthening of both the clay and concrete. X-ray diffraction and electron microscopy analysis of the material revealed an increasing degree of cation exchange at higher temperatures with the cement, whereby Ca replaced Na in the interlayer sites of smectite layers. Dissolution of illite/smectite was also evident occurring at enhanced temperatures, with a decrease in K, Mg and Fe content with advanced alteration. The enhanced strength of clay can be partly attributed to the precipitation of cement phases from circulating fluids, including precipitation of gypsum.

  • 191.
    Hermansson, Åke
    et al.
    VTI - Statens väg-och transportforskningsinstitut.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Discussion of paper 01-0121 by Parker, Buch and Chatti Discussion to paper given by Parker, Buch and Chatti, entitled "Development of Effective Layer Temperature Prediction Model and Temperature Correction Using FWD Deflections2001Inngår i: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, Vol. 1699Artikkel i tidsskrift (Annet vitenskapelig)
  • 192.
    Hoang-Minh, Thao
    et al.
    VNU University of Science, Vietnam National University, Hanoi.
    Kasbohm, Jörn
    Greifswald University, Greifswald, Germany.
    Nguyen-Thanh, Lan
    Institute of Applied Geosciences, Technical University of Darmstadt, Darmstadt, Germany.
    Nga, Pham Thi
    VNU University of Science, Vietnam National University, Hanoi, Vietnam.
    Lai, Le Thi
    Institute of Geological Sciences, Vietnam Academy of Science and Technology, Vietnam.
    Duong, Nguyen Thuy
    VNU University of Science, Vietnam National University, Hanoi, Vietnam.
    Thanh, Nguyen Duc
    Advance Technology Transfer and Consultancy Co., Hanoi , Vietnam.
    Thuyet, Nguyen Thi Minh
    VNU University of Science, Vietnam National University, Hanoi, Vietnam.
    Anh, Dao Duy
    National Institute of Mining – Metallurgy Science and Technology, Hanoi, Vietnam.
    Pusch, Roland
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Mählmann, Rafael Ferreiro
    Institute of Applied Geosciences, Technical University of Darmstadt, Darmstadt, Germany.
    Use of TEM-EDX for structural formula identification of clay minerals: a case study of Di Linh bentonite, Vietnam2019Inngår i: Journal of applied crystallography, ISSN 0021-8898, E-ISSN 1600-5767, Vol. 52, nr 1, s. 133-147Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Transmission electron microscopy linked with energy-dispersive X-ray spectroscopy (TEM-EDX) was applied to characterize mineralogical signals ofweathering processes in the Di Linh bentonite deposit (Vietnam) and to visualize the effects of Na activation on the smectitic phases. Modelling of X ray diffraction patterns (oriented mount) was applied in order to refine the computed structural formula. X-ray diffraction, X-ray fluorescence and Fouriertransform infrared spectroscopy (FT-IR) methods were also applied to verify the TEM-EDX results. An Excel-based routine has been developed in this research to allow fast computation of structural formulae and classification of the investigated clay particles. This routine supports the acquirement of 100 300 TEM-EDX analyses as a representative set of individual particles for each sample. The Excel-based routine involves end members of different clay mineral groups and interstratifications with two or three members (e.g. illite smectite interstratifications – IS-ml; dioctahedral vermiculite–smectite interstratifications – diVS-ml; and kaolinite–montmorillonite–dioctahedral vermiculite interstratifications – KSV-ml). The routine is now freely available. According to the identification procedure, the <2 mm fraction of the Di Linh bentonite (Vietnam) is composed mainly of K- and charge-deficient illite smectite interstratifications (or diVS-ml): montmorillonite-rich randomly ordered (R0) type and illite-rich regularly ordered (R1) type. Additionally, Fe-poor KSV-ml was identified.Industrial Na activation of the Di Linh bentonite resulted in an increase of theR1 diVS-ml portion and dissolution of a large part of the smectite-rich phases.The TEM-EDX approach also gave analytical proof of a sedimentary processfor Di Linh smectite. The parent muscovite was altered in two different environments: (i) K-leaching and layer-wise alteration into kaolinite (weathering), and (ii) further edge-controlled alteration of mica into lath-like montmorillonite particles associated with a dissolution of kaolinite layers from the former kaolinite–mica intergrowths by heat impact (basalt flow).

  • 193.
    Huang, Yi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jia, Qi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    The one dimensional model for coarse particle around mining area in northern Sweden2012Inngår i: Journal of Advanced Science and Engineering Research, ISSN 2231-8844, Vol. 2, nr 2, s. 126-137Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Computational model had been established to predict the coarse dust transport rate within the Malmberget mining area in northern Sweden. Matlab GUI designing had been introduced to enhance the computation process. Certain modification methods were developed in order to improve the accuracy of the model. Dust retention time was calculated to estimate the dust transport in the suspension form. Field calibration proves the code works fairly well for the coarse dust in the research area.

  • 194.
    Huang, Yi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jia, Qi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    The simulation of the dust grain movement by sediment transport model around mining area in northern Sweden2012Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 2, nr 2, s. 1-11Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A simple sediment transport model has been utilized to simulate the dust grain movement in the area flow. The transport model can be used as a tool to estimate the dust grain transport situation in a mining area with consideration of the local topographical profile. The case study of the local dust characteristics survey proves the model works fairly well compared to the field calibration.

  • 195.
    Hussain, Hussain M.
    et al.
    Department of Geology, Faculty of Science, University of Kufa.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Groundwater Pollution Potential in Part of the Western Desert, Iraq2015Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 5, nr 1, s. 1-17Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The growth of human population often corresponds with change in land use, including expansion of urban areas, which necessitates increasing the available amount of drinking water. As the surface water sources are more amenable to pollution, it has become necessary to use groundwater at an increasing rate. Groundwater is normally abundant in the alluvial region where the urban areas are often located. Such areas face a greater risk of pollution of groundwater due to several factors. Surface water resources are becoming more scares in Iraq which gave a tendency to use groundwater. In this research, groundwater vulnerability in part of the western desert had been studied. It was noticed that the area has low risk for the contamination of ground water.

  • 196.
    Hussain, Hussain Musa
    et al.
    Department of Geology, Faculty of Science, University of Kufa.
    Al-Haidarey, Mohammed
    Department of Ecology, Faculty of Science, University of Kufa.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Evaluation and Mapping Groundwater Suitability for Irrigation Using GIS in Najaf Governorate, Iraq2014Inngår i: Journal of Environmental Hydrology, ISSN 1058-3912, E-ISSN 1996-7918, Vol. 22, artikkel-id 4Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Irrigation Water Quality Index (IWQI) for groundwater within the Geographic Information System(GIS) environment is proposed so that it can be used in assessing the groundwater vulnerability. Themodel was applied to the Damman aquifer in the western part of Iraq. Thirty nine sites were chosen forthe investigation of the Damman aquifer. Triplicate ground water samples were collected from eachsite (during wet and dry seasons of 2013). Variables tested in each sample include: pH, EC, totalhardness Ca+2, Mg+2, Cl-, Na+ and SAR. The final water quality map constructed for the aquifershowed that there are three major regions. The first is in the northeastern part of the area while thesecond region is confined to the southeastern part. Finally, the third region extended along the westernpart of the study area. When this map was converted according to the suggested model, it showed thatthe water quality of the Damman aquifer is marginal for use for agriculture purposes.Journal

  • 197.
    Issa, Issa E.
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Khaleel, Moayad
    Mosul University.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Experimental Analysis of Sediment Deposition Due to Backwater Effect up-stream a Reservoir2014Inngår i: Journal of Civil Engineering and Architecture, ISSN 1934-7359, E-ISSN 1934-7367, Vol. 8, nr 9, s. 1185-1193Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The phenomenon of aggradation due to sediment accumulation upstream reservoirs had been studied in this research. For this purpose, group of experiments were conducted in a laboratory channel 25 m long, 0.80 m wide and 0.70 m deep. A block was built at the end of the channel to work as a dam to impound water. The channel was supplied with drainage pipes on both sides to release water out in a manner similar to what happens in reservoirs. The bed of the channel was filled with sand of 0.80 mm median sieve diameter and 0.72 geometric standard deviation. The slope was 0.0093 for all experiments. Two sizes of sand were used representing the sediment. The median diameter and geometric standard deviation of the first were 0.365 mm and 0.46 respectively. The second sample had 0.65 mm median diameter and 0.67 standard deviation. A total of seventy experiments were conducted in two groups to examine effect the sediment transport rate, particle size of sediment and flow velocity on aggradation characteristics. The results showed that there is a strong linear direct relationship between aggradation elements (length and depth) with the rate of sediment transport. Group of dimensionless parameters affecting the aggradation characteristics were used to develop empirical equations to predict the length, maximum depth of aggradation and predict transient bed profile. The results of empirical approach were compared with the measurement data and previous numerical method. The results indicated that the percentage error was –19 to 31% for length of aggradation and –21 to 26% for maximum depth of aggradation. The results also showed that the sediment material were deposited closer to the body of the dam when the released water from the dam is higher than the inflow.

  • 198.
    Issa, Issa E
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Assessment of Sedimentation Characteristics and Capacity Curve for Mosul Dam Reservoir, Iraq2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The sedimentation process is the most important problems that affect directly the performance of reservoirs due to the reduction of the storage capacity and possible problems effecting the operation. Thus periodic assessment of the storage capacity and determining sediment deposition patterns is an important issue for operation and management of reservoirs. In this study, bathymetric survey results had been used to assess the characteristics of sedimentation of Mosul Reservoir. It is located on the Tigris River in the north of Iraq. The water surface area of its reservoir is 380 km2 with a designed storage capacity of 11.11 km3 at a maximum operating level (330 m a.s.l). The dam started operating in 1986. No detailed study was yet carried out to assess its reservoir. The present study indicated that the annual sediment deposited in the reservoir is 45.72 × 106 m3year-1 which is divided into 23.2 × 106 and 22.52 × 106 m3year-1 for dead and live zones respectively. This implies the annual reduction rate in the dead and live storage capacities of the reservoir is 0.786% and 0.276% respectively. Furthermore, the stage-storage capacity curves for the future periods (prediction curves) were assessed using 2011 bathymetric survey data.

  • 199.
    Issa, Issa E.
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Assessment sedimentation rate in the Mosul dam reservoir, Iraq2013Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Mosul dam is one of the biggest hydraulic structures in Iraq that was built on the Tigris River 60 km north-west Mosul city north of Iraq. The water surface area of its reservoir is 380 km2 with a storage capacity of 11.11×109 m3 at a maximum operation level (330 m.a.s.l). The dam became operational in 1986. No study has been conducted to determine the sedimentation rate, storage capacity and new operational curve since that date. To develop an up to date operational curve, a new bathymetric survey was conducted in 2011. The results indicated that the reduction in the storage capacity of the reservoir was 10.29 %. This implies that the annual sedimentation rate within the reservoir was 45.72×106 m3.yr-1 (0.41%) that is less than the average worldwide rate. Consequently, a new operational curve was constructed.

  • 200.
    Issa, Issa E.
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Changes in bed morphology of Mosul dam reservoir2013Inngår i: Journal of Advanced Science and Engineering Research, ISSN 2231-8844, Vol. 3, nr 2, s. 86-95Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mosul dam is one of the biggest hydraulic structures in Iraq. It was constructed on the Tigris River in the north of Iraq for multiple purposes: irrigation, flood control and power generation. The initial storage capacity and water surface area of its reservoir reach 11.11 km3 and 380 km2 respectively at the maximum operation level 330 m.a.s.l. The dam was operated in 1986. Since that time no survey has been conducted to determining the characteristics of sedimentation in the reservoir. Blockage of the intakes of the pump station for North Al-Jazira Irrigation Project in Mosul dam reservoir has highlighted the importance of sedimentation problems within the reservoir.Sediment distribution was studied within the reservoir. A comparison was made between the conditions at the start of the dam operation and a recent bathymetric survey conducted in 2011.The former was achieved using a topographic map scale 1: 50000 dated 1983 which was converted to a triangular irregular network (TIN) format using the Arc/GIS program. The results of the bathymetric survey were also converted to the TIN map format using the above program. Comparison of the two maps shows that the sedimentation magnitude in the upper zone of the reservoir, where the River Tigris enters, was highest and gradually reduced toward Mosul dam site. Maximum deposition thickness within the reservoir was 17.6 m. The thalweg bed slope of the River Tigris within reservoir area changed from 0.65 m.km-1 before dam construction to 0.71 m.km-1 on the 2011 survey. Zones within the

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