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  • 201.
    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.
    Mosul Dam Resorvoir Sedimentation Characteristics, Iraq2014Inngår i: Journal of Environmental Hydrology, ISSN 1058-3912, E-ISSN 1996-7918, Vol. 22, artikkel-id 3Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sediment transported by rivers and finally deposited in reservoirs directly affects dam performanceand causes a reduction in their storage capacity and hence operating efficiency. In this study, thesedimentation characteristics of Mosul dam reservoir have been evaluated using two topographic mapsof the reservoir area at different times (1986 and 2011) via Arc/GIS software. The dam is located on theTigris River in the northern part of Iraq and started operating in 1986. The water surface area of itsreservoir is 380 km2 with a designed storage capacity of 11.11 km3 at a maximum operating level (330m a.s.l). The results showed that the annual sediment deposition rate is 45.72 × 106 m3 year-1 of which23.2 × 106 and 22.52 × 106 m3 year-1 are in the dead storage and live storage zones respectively. As aconsequence, the live and dead storage zones lost 6.9% and 19.66% respectively of their storagecapacity during the 25 year of operation of the dam. The water-spread area (water surface area) of thereservoir at dead storage level (300 m a.s.l) was reduced annually by about 1.34 km2. Furthermore,the stage-storage capacity curves for future periods (prediction curves) were assessed and comparedwith adopted prediction curves using 2011 bathymetric survey data.

  • 202.
    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.
    Sedimentation and new operational curves for Mosul Dam, Iraq2013Inngår i: Hydrological Sciences Journal, ISSN 0262-6667, E-ISSN 2150-3435, Vol. 58, nr 7, s. 1456-1466Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mosul dam is one of the biggest hydraulic structures in Iraq. Its storage capacity is 11.11×109 m3 at a maximum operation level 330 m of a.s.l. The dam became operational in 1986 and no survey has been conducted to determine its storage capacity and establish new operational curves since this date. In this research topographic map scale 1: 50000 dated 1983 was converted to triangulated irregular network (TIN) format using the Arc/GIS program to evaluate the operational curves. Then the reservoir was surveyed in 2011 to establish the reduction in its storage capacity and to develop new operational curves. The results indicated that the reduction in the storage capacity of the reservoir was 14.73%. This implies that the rate of sedimentation within the reservoir was 45.72×106 m3.yr-1. The results indicated that most of the sediment was deposited within the upper zone of the reservoir where the River Tigris enters the reservoir.

  • 203.
    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.
    Khaleel, Moayad
    Mosul University.
    Sediment delivered in the upper part of Mosul reservoir using physical model2012Inngår i: Journal of Civil Engineering and Architecture, ISSN 1934-7359, E-ISSN 1934-7367, Vol. 6, nr 11, s. 1544-1550Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mosul dam is the biggest hydraulic structure in Iraq located on the River Tigris 60 km northwest of Mosul city. Its storage capacity is 11.11 × 109 m3 and it had been in operation since 1986. A physical distorted model with movable bed having a vertical scale 1:100 and a horizontal scale 1:1000 was used to conduct the experiments relating the water level at the reservoir and water discharge upstream the reservoir with the bed load transport rate. The model represents the first 15 km of most northern part of Mosul dam reservoir. The construction of the model was based on bathymetric survey conducted in 2009. Twenty-four experiments were executed using four different discharges (0.5, 1.0, 1.5, and 2.0 L/s) which represent the average discharges in the flood period of River Tigris. At each individual discharge six operations were assumed where the reservoir’s water level was 305, 307, 309, 310, 312, 315 meters above sea level respectively. In all the experiments conducted, bedload transport was measured in the physical model at section representing the River Tigris 1 km upstream the reservoir. The results showed that the bedload rate was decreasing when the water level within the reservoir was increasing. It was also evident that bedload transport rate dramatically decreased at level 310 meter above sea level onward. This is due to the fact that at this level represent the effect of backwater which was noticeable on the river cross section.

  • 204.
    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.
    Khaleel, Moayad
    Mosul University.
    The effect of operation of Mosul dam on sediment transport in its reservoir2012Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Mosul dam is the biggest hydraulic structure in Iraq located on the River Tigris 50 Km north of Mosul city. Its storage capacity is 11.1 x 109 m3 and it had been in operation since 1986.A physical model representing the most northern part of Mosul dam reservoir was used to conduct the experiments. The construction of the model was based on field survey conducted in 2010. Twenty-four experiments were executed using four different discharges (500, 1000, 1500 and 2000 m3/s respectively). At each individual discharge six operations were assumed where the reservoirs water level was 305,307,309,310, 312, 315 MSL respectively. In all the experiments conducted, bedload transport rate was decreasing when the water level within the reservoir was increasing. It was also evident the bedload transport rate dramatically decreased at level 310 onward. This is due to the fact that at this level the effect of backwater was noticeable on the river cross section

  • 205.
    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.
    Sherwany, Govand
    Ministry of Higher Education and Scientific Research—KRG, Erbil.
    Monitoring and Evaluating the Sedimentation Process in Mosul Dam Reservoir Using Trap Efficiency Approaches2015Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 7, nr 4, s. 190-202Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Reservoirs are usually exposed to sediment accumulation problems that will lead to reduction in their storage capacity. This problem directly affects the performance of the dams and causes shortage of their useful life. The simplest technique to estimate sediment deposition rate is using sediment rating curve with sediment trapping efficiency (TE) of the reservoir. Many empirical and semi-empirical approaches have been suggested for to determine this term depending on the annual inflow rate, reservoir characteristics and features of the catchments area. In this study six different empirical methods depending on the residence time principle (water retention time) were used. These approaches were reviewed and applied to determine TE of Mosul dam reservoir (MDR) for period 1986 to 2011. The monthly operating data for inflow, outflow and water elevations for MDR were used to determine monthly TE and long-term TE for whole period of MDR using the mentioned methods. Furthermore, the monthly inflow rate for River Tigris upstream MDR, its sediment rating curve and sediment feeding from valleys around MDR were used to estimate the amount sediment coming to the reservoir. The results provided by these methods for TE withsediment coming to MDR were used to compute the amount of sediment deposited in MDR on monthly bases during this period. The results obtained were evaluated using observed bathymetric survey data that had been collected in 2011 after 25 years of the operation of the dam. The results showed all the mentioned methods gave convergent results and they were very close to bathymetric survey results for estimating the volume of sediment deposited especially that proposed by Ward which gave 0.368% percentage error. Furthermore, the result computed using monthly TE gave good agreement if compared with that long-term TE where the percentage error was ranging between −3.229% to 1.674% for monthly adopted data and −4.862% to −2.477% for whole period data. It is believed that this work will help others to use this procedure on other reservoirs.

  • 206.
    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.
    Sherwany, Govand
    Ministry of Higher Education and Scientific Research, Kurdistan Region.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Expected Future of Water resources within Tigris–Euphrates Rivers basin, Iraq2014Inngår i: Journal of Water Resource and Protection, ISSN 1945-3094, E-ISSN 1945-3108, Vol. 6, nr 5, s. 421-432Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Iraq is one of the riparian countries within basins of Tigris-Euphrates Rivers in the Middle East region. The region is currently facing water shortage problems due to the increase of the demand and climate changes. In the present study, average monthly water flow measurements for 15 stream flow gaging stations within basins of these rivers in Iraq with population growth rate data in some of its part were used to evaluate the reality of the current situation and future challenges of water availability and demand in Iraq. The results showed that Iraq receives annually 70.92 km3 of water 45.4 and 25.52 km3 from River Tigris and Euphrates respectively. An amount of 18.04 km3 of the Tigris water comes from Turkey while 27.36 km3 is supplied by its tributaries inside Iraq. The whole amount of water in the Euphrates Rivers comes outside the Iraqi borders. Annual decrease of the water inflow is 0.1335 km3 year-1 for Tigris and 0.245 km3 year-1 for Euphrates. This implies the annual percentage reduction of inflow rates for the two rivers is 0.294% and 0.960% respectively. Iraq consumes annually 88.89% (63.05 km3) of incoming water from the two rivers, where about 60.43 and 39.57 % are from Rivers Tigris and Euphrates respectively. Water demand increases annually by 1.002 km3; of which 0.5271 km3 and 0.475 km3 within Tigris and Euphrates basins respectively. The average water demand in 2020 will increase to 42.844 km3 year-1 for Tigris basin and for Euphrates 29.225 km3 year-1 (total 72.069 km3 year-1), while water availability will decrease to 63.46 km3 year-1. This means that the overall water shortage will be restricted to 8.61 km3.

  • 207.
    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.
    Sherwany, Govand
    Ministry of Higher Education and Scientific Research, Kurdistan Region.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Sedimentation processes and useful life of Mosul dam Reservoir, Iraq2013Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 5, nr 10, s. 779-784Artikkel i tidsskrift (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 the reservoirs. In this study, bathymetric survey results and an analytical approach had been used to assess the characteristics of sedimentation and estimate the useful life 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 reduction rate in the dead and live storage capacities of the reservoir is 0.786% and 0.276% respectively. The observed results (bathymetric survey) and algebraic formula show approximately that the useful life of Mosul dam reservoir is about 125 years. Furthermore, the stage-storage capacity curves for the future periods (prediction curves) were established using bathymetric survey data.

  • 208. Jantzer, Isabel
    et al.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Critical gradients for tailings dam design2010Inngår i: Mine Waste 2010: First International Seminar on the Reduction of Risk in the Management of Tailings and Mine Waste ; proceedings of the First International Seminar on the Reduction of Risk in the Management of Tailings and Mine Waste ; 29 September - 1 October 2010, Perth, Australia / [ed] Andy Fourie; Richard Jewell, Nedlands, Western Australia: Australian Centre for Geomechanics, 2010, s. 23-32Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Knowledge on tailings dams design is often derived from conventional earth- and rockfill dams mostly designed for relatively short service periods. Tailings dams often differ in structural design and service life, where a long term stability of 1000 years or more is demanded. One of the most important factors related to tailings dams stability and performance in long term perspective is the prevention from internal erosion, i.e. particle migration initiated by seepage pressure. Internal erosion is a process not yet completely understood; it is related to the seepage rate, which is in turn is connected to the hydraulic gradient, internal structure, particle size distribution etc. The hydraulic gradient is therefore crucial for embankment stability and prevention of particle migration for a given material, and a basic research question is: Does a maximum hydraulic gradient exist in a given material? If so, what maximum gradient can we allow for a tailings dam construction in order to prevent internal erosion with respect to the long term stability of the construction? The maximum, or critical, gradient is often related to slope stability problems, heave, or blow out. Such critical values differ from a critical hydraulic gradient for erosion problems inside the soil matrix. To be able to apply critical values on internal erosion problems, clear definitions and information on the origin of a given critical hydraulic gradient is needed. The paper presents a detailed literature survey on reported values of critical hydraulic gradients for the initiation of piping shows that values range between 4,8 and 14 %. These values are derived from laboratory tests and from experiences of conventional dam constructions, i.e. they have to be looked upon in a limited time perspective. The paper discusses the use of these values for tailings dams design. To take the long term aspect into account, natural analogies to dam constructions have been analyzed. These structures are formations from the last glaciation that have fulfilled the task of damming water. Such structures are especially interesting with regard to their obvious stability against internal erosion over long time periods. Such natural formations are analyzed and presented in the paper. Results show that they are stable under a hydraulic gradient between 2 to 5 %. Current guidelines on tailings dam design in Sweden allow a hydraulic gradient where both the long term stability of the construction and the possible degradation of the construction material is not taken into account. To ensure a long term stability of tailings dam constructions, a more thorough understanding of the critical gradient in long term perspective is needed, and a modification of the present design guidelines is suggested.

  • 209. Jantzer, Isabel
    et al.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Critical hydraulic gradients in tailings dams in long term perspective2010Inngår i: Mine closure 2010: proceedings of the Fifth International Conference on Mine Closure ; 23 - 26 November 2010, Viña del Mar, Chile / [ed] Andy Fourie; Mark Tibbett; Jacques Wiertz, Nedlands, WA: Australian Centre for Geomechanics, 2010, s. 541-554Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The stability of tailings dams in long term perspective depends, amongst others, on the prevention of internal erosion, a process that results from an exceeding seepage pressure causing particles in a dam to migrate, with possible consequences of damage and failure of the dam construction. Therefore, a major questions for tailings dam design is: What maximum hydraulic gradient can we allow for a tailings dam construction in order to prevent internal erosion in a long term perspective, i.e. over a time period > 1000 years? With regard to this long term design of tailings dams, natural analogies to dam constructions are considered, i.e. formations from the last glaciation period that have fulfilled the task of damming water. Such structures are especially interesting with regard to their obvious stability against internal erosion over long time. Consequently, it is assumed that a critical hydraulic gradient exists, and that the material composition and compaction reaches an optimum which allows seepage without erosion. A literature study on critical hydraulic gradients is conducted. Relevant natural analogies to dam constructions are identified and analyzed with respect to the gradient. In addition, a case study on such a natural formation is carried out. Results on hydraulic gradients are then compared to current design guidelines for tailings dams in Sweden. Results of this study show that critical hydraulic gradients given in the literature range between 4,8 and 14 %, whereas gradients in long term stable natural formations are between 2 to 5 %. Current guidelines on tailings dam design in Sweden relate the maximum gradient to the internal angle of friction, thus resulting in gradients of about 12 to 27 %. With regard to long term stability, possible degradation and results from comparisons to long term stable natural analogies, a modification of the design criteria for Swedish tailings dams should be considered.

  • 210. Jantzer, Isabel
    et al.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Effects of freezing and thawing in embankment dams2007Inngår i: International Symposium on Modern Technology of Dams: The 4th EADC Symposium, Chinese National Committee on Large Dams , 2007, Vol. 1, s. 543-556Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Embankment dams located in cold climate are subjected to freezing condition, which is usually not taken into account in the design. Frost susceptible fill material may be exposed to frost action, a process known for ice lens formation which increases water content and soil volume. Upon thawing, rearrangement of particles takes place and the soil structure is altered. Fine grained soils may therefore exhibit weak zones with reduced shear strength and increased hydraulic conductivity. Internal erosion may start in such weak zones, thus causing problems for the dam construction. Therefore, climate should be considered in order to find temperature distribution and pore pressures in the embankment. A study of freezing effects has been carried out at the Suorva hydropower embankment dam in northern Sweden. The study included field investigations, i.e. test pit excavation, where weak zones have been observed. The comparison of results to those from temperature calculations with a commercial finite element program showed that the core is exposed to frost action, thus causing seepage problems.

  • 211. Jantzer, Isabel
    et al.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Seepage and critical hydraulic gradients in tailings dams and natural formations2007Inngår i: Proceedings of the 2nd International Conference on Porous Media and its Applications in Science and Engineering, ICPM2: June 17-22, 2007, Kauai, Hawaii, USA, Engineering Conferences International , 2007Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Embankment dams, both water Retention Dams (WRD) and tailings dams, are constructed of granular material. Natural seepage flow through porous media, i.e. soil, rock, and tailings, occurs in all types of dams. During this process, particles in the porous media are exposed to hydraulic gradients. Under certain circumstances seepage can initiate internal erosion which can seriously damage the construction, eventually resulting in serious accidents or failure. The process starts when a critical hydraulic gradient is reached, which may vary with the way of construction, materials used and its properties and compaction. This is of special importance for dams constructed of mine waste, i.e. tailings dams, where the stability and function has to be guaranteed over very long time periods (>1000 years). Here, seepage, internal erosion and the corresponding critical gradient are fundamental parameters. It is not clear under which circumstances the process of internal erosion begins, i.e. when one particle in the system starts to move, thus creating a further process of particle transportation in the system. To common way to control seepage, filter layers are included in the construction. However, erosion, piping or sinkholes are still observed. Different models on the hydraulic conductivity and hydraulic gradient are presented and discussed.  Properties of tailings in comparison with natural geological materials are identified. Observations from several natural geological formations in Sweden, which have fulfilled the function of a dam since the last glaciation, are presented and the critical hydraulic gradients with respect to vary long time periods are compared.

  • 212.
    Jia, Qi
    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.
    Dust emission from unpaved roads in Luleå, Sweden2013Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 3, nr 1, s. 1-13Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The dust emission from unpaved roads, if not controlled, can cause enormous problems. Though a few real-world measurements of road dust have been done by automated samplers in Sweden, measurement by BSNE (Big Spring Number Eight) and the estimation of total dust generation from vehicle driving is rare. This study measured and analyzed dust emission by BSNE at two unpaved roads in Luleå, Sweden, at the driving speed of 20, 30, 40, and 50 km/h different heights. Even though US EPA excluded vehicle speed as a parameter in estimating dust emission factors for unpaved roads, this study confirmed a strong dependence of dust emission on vehicle speed. This is in agreement with several recent studies which concluded dust emission increases with driving speed exponentially or linearly, however the power law is the best description for the data from this study. The comparison with estimated dust emission by US EPA’s equation showed the equation underestimates the dust emission more than 50 percent when vehicle speed and silt content is higher than 25.40km/h and 2.17 percent respectively. There might be some interrelationship between driving speed and silt content in road surface.Earlier researchers have reported increased dust emission with increasing silt content and this is confirmed by this study.

  • 213.
    Jia, Qi
    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.
    Dust generation within the vicinity of Malmberget mine, Sweden2011Inngår i: Applied Mechanics and Materials, ISSN 1660-9336, E-ISSN 1662-7482, Vol. 90-93, s. 752-759Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mining activities are usually associated with environmental impacts, particularly that of air pollution by fugitive dust. Malmberget mine is one of the most important iron mines in Sweden and the dust problem has been noticed by the inhabitants for a long time. Dust collectors had been installed to measure the dust fallout around the mining site. In this research the dust fallout recorded during the period August 2006 till July 2010 were analyzed. Generally speaking the amount of dust fallout was decreasing year by year due to some implemented dust control methods. Mining activities produced more dust during summer than winter. The peak value was 265g/100m2/30d appeared in May 2007, and the lowest dust fallout was 25g/100m2/30d happened in August 2009. Dust was determined to be originated from the open pit area and the industrial center area. Truck transportation on the haul roads, wind erosion of stockpiles and exposed areas were the main activities that caused dust generation.

  • 214.
    Jia, Qi
    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.
    Estimation of road dust using BSNEs2013Inngår i: Natural Science, ISSN 2150-4091, E-ISSN 2150-4105, Vol. 5, nr 5, s. 567-572Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mining is a core industry in Sweden and plays an important role in the economic development of the country. Though the importance of mining dust has been well recognized, the quantification of dust production with regard to individual source activity has rarely been done in Sweden. Depending on the type of source activity, dust estimation method can be chosen from three alternatives: exposure profiling methods, back calculation method, and wind erosion prediction method. Also included in the paper is an example of experiment, which was executed on two unpaved roads in Lulea, Sweden by using exposure profiling method. The experiment concluded that dust emission due to vehicle transportation is strongly dependent on traveling speed and road bed material.

  • 215.
    Jia, Qi
    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.
    Evaluation of dust fallout at malmberget mine, Sweden for the period August 2009 to August 20102011Inngår i: Journal of Advanced Science and Engineering Research, Vol. 1, nr 2, s. 246-260Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Dust is produced when mining operations take place. The transportation and deposition of dust depend mainly on climatic factors, as well as land surface characteristics. Malmberget mine operated by Luossavaara-Kiirunavaara Aktiebolag is one of the most important iron mines in Sweden. The mining area includes an area with a huge open pit and an industrial center. Both sites are surrounded by residential areas where people are suffering from dust problems. The collected dust from 26 measuring stations during the period 2001 to 2010 has been analyzed using the surfer 9.0 program. Generally speaking the dust fallout in summer was higher than that in winter and the volumes decreased through time as a result of implemented dust control methods. Analysis of the data from August 2009 to August 2010 indentified two sources of dust generation. One was located close to the open pit, and the other near the current mining industrial center. Among all the measuring stations, the maximum and minimum values within the year were 1284 g/100m2/30d and 9 g/100m2/30d, respectively. Dust production around the Malmberget mine was attributed to three reasons, namely, wind erosion of the exposed area close to the open pit, truck transportation on haul roads, and wind erosion of stockpiles. In addition to climatic factors, the variation of dust detected depended on mining activities and road construction.

  • 216.
    Jia, Qi
    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.
    Measurement of dust emission from a road construction using exposure-profiling method2013Inngår i: Journal of Natural Science, ISSN 0075-4307, Vol. 5, nr 12, s. 1255-1263Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Road construction is one example of heavy constructions that may have a substantial temporary impact on local air quality. Construction of Luleå Road during the summer 2013 generated a great deal of dust emission. US EPA recommended exposure-profiling method was used to measure dust emission. Inexpensive BSNE dust samplers were used instead of high volume samplers. The objective was to give a general idea of the amount of dust generated due to the construction work. Dust generation related to weather was discussed conditions. Estimated threshold wind velocity for road surface materials at the height of 2m were 12.88m/s, 12.88m/s and 24.76m/s which were lower measured wind velocity, indicated no dust generated from wind erosion. Dust masses for 7 sampling periods show dust generation had a close relation with moisture content of surface material. Wind speed, humidity had minor or no effect. The estimated dust emission rate in the construction work during the measuring period was 22.86kg TSP/d, 6kg/d was from construction work and 16.86kg/d was generated due to traffic on temporary roads.

  • 217.
    Jia, Qi
    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.
    Modeling of wind erosion of the Aitik tailings dam using SWEEP model2014Inngår i: Engineering, ISSN 1947-3931, E-ISSN 1947-394X, Vol. 6, nr 7, s. 355-364Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Waste impoundments are usually not protected by any growing crops, soil roughness, or wind barriers, and dust due to wind erosion of the surface waste material can be a major environmental problem. The tailings dam in Aitik is highly susceptible to wind erosion when it is dry and windy. Strong dust storms may occur during dry seasons. These events are short-lived but may transport a huge amount of particulate matter and adversely impact air quality in downwind areas. This study estimated material loss from the Aitik tailings dam using SWEEP model. The simulated total material loss, saltation and creep loss, suspension loss and PM10 loss were 4.4941kg/m2, 0.042 kg/m2, 4.4559 kg/m2, 0.264057 kg/m2 respectively. To control the dust generation wind breaks could be suggested to be installed at 800m downwind the upwind edge of the tailings dam to reduce the saltation and creep and it would in turn reduce suspended emission. The measured total suspended material for five days by exposure profiling method was 0.475kg/m2, which had a big difference with simulate a value of 4.4559 kg/m2. Many reasons contributed to the disagreement of simulated value and measured value in this study. In order to use the model for mining industry more tests are needed to validate the modeling result and calibration methods could be useful in adjusting the internal coefficients and empirical equations.

  • 218.
    Jia, Qi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Huang, Yi
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Dust emissions from landfill deposition: a case study in Malmberget mine,Sweden2013Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 3, nr 3, s. 25-34Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A great amount of industrial wastes are produced in Sweden every year. In 2008 there were 97.9 million tons of wasted generated, among which 93 million tons industrial waste were produced. 64.1% of industrial wastes were deposited in the landfill sites. Dust generation is one of the most important problems associated with industrial waste and landfills. The particulate dust emissions come from the industrial waste may contain heavy metal and produce environmental problems and potential health risks. Active and passive samplers, deposition pans are common equipment to collect dust samples. Real-time monitors use laser diffraction to recording continuous dust concentration. Dust emission from Malmberget mine in Sweden was analyzed as a case study. Dust was collected by NILU deposit gauge from 26 stations. Generally speaking the amount of dust fallout was decreasing with time because of implemented dust control methods. During the period August 2009 to August 2010, among all the measuring stations through the year, the maximum and the minimum value were 1284 g/100m2/30d and 9 g/100m2/30d. Two sources of dust generation were identified. The first was located close to the open pit, and the second near the current mining industrial center. The dust generation due to road construction was calculated.

  • 219.
    Jia, Qi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Huang, Yi
    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.
    Dust emissions from landfill due to deposition of industrial waste: a case study in Malmberget mine, Sweden2011Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    A great amount of industrial wastes are produced in Sweden every year. In 2008 there were 97.9 million tons of wasted generated, among which 93 million tons industrial waste were produced. 64.1% of industrial wastes were deposited in the landfill sites. Dust generation is one of the most important problems associated with industrial waste and landfills. The particulate dust emissions come from the industrial waste may contain heavy metal and produce environmental problems and potential health risks. Active and passive samplers, deposition pans are common equipment to collect dust samples. Real-time monitors use laser diffraction to recording continuous dust concentration. Dust emission from Malmberget mine in Sweden was analyzed as a case study. Dust was collected by NILU deposit gauge from 26 stations. Generally speaking the amount of dust fallout was decreasing with time because of implemented dust control methods. During the period August 2009 to August 2010, among all the measuring stations through the year, the maximum and the minimum value were 1284 g/100m2/30d and 9 g/100m2/30d. Two sources of dust generation were identified. The first was located close to the open pit, and the second near the current mining industrial center. The dust generation due to road construction was calculated. On the other hand dust generation was also closely related to weather conditions.

  • 220.
    Jia, Qi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Huang, Yi
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Particle characterization and determination of erodible fraction of surface soil nearby the open pit in Malmberget mine, Sweden2011Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Wind erosion of soil from exposed areas in mining sites is one of the sources for dust generation. Particle size distribution and mineralogical composition of source soil, erodible fraction of surface soil, moisture, as well as organic matter content are important factors that determine the property of particulate generation process. In this research four soil samples were taken using shovel at different depth from the edge of the pit and the surface area nearby the pit in Malmberget mine in Sweden. Soil samples were analyzed for density, particle size, mineralogical composition, organic matter content, and CaCO3 content. No calcite was detected by Qemscan and consequently, CaCO3 was assumed absent in the soil samples. Moisture contents in the surface samples were too little to prevent soil from wind erosion. All soil samples were mainly composed of albite, quartz, and K felspar. Miner minerals such as mineral 23 (bFe, bCa), as well as grossular, were more abundant within the surface samples while the reverse is true for ilment. It should be mentioned, however, that undersurface samples contained more particles of 100 μm in diameter compared to surface samples. Measured erodible fractions for surface samples were 35.9% and 43.39%. The erodible fraction was calculated for the soil of the studied area but the equations could not be applied because the calculated values were overestimated. The value of soil erodibility index was determined to be 19t/acre which was wind erosion group 7. Since wind erosion group 7 is not a highly intrinsic erodible soil group, the dust problem might also arise from disturbances of soil surface soils by trucks and other construction activities around the open pit.

  • 221.
    Jia, Qi
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Yang, Qixing
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Guo, Lijie
    Beijing General Research Institute of Mining and Metallurgy.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Xue, Peng
    Department of Ferrous Metallurgy, School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing.
    Liu, Guiqun
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi.
    Jiang, Liang
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Mineralteknik och metallurgi. jiang.liang@ltu.se .
    Effects of fine content, binder type and porosity on mechanical properties of cemented paste backfill with co-deposition of tailings sand and smelter slag2016Inngår i: The Electronic journal of geotechnical engineering, ISSN 1089-3032, E-ISSN 1089-3032, Vol. 21, nr 20, s. 6971-6988Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mine backfilling is a process where the underground voids resulted from mining are filled with waste materials. The potential of co-depositing iron sand produced from smelting process with tailings sand was investigated in the present study. Different amounts of iron sand were mixed with the tailings sand to prepare cemented paste backfill (CPB) samples. Two types of binders were used. Uniaxial compression tests were performed for the CPB samples after 28 days of curing. The porosities of the samplers after curing were calculated to correlate the porosity with the uniaxial compression strength, UCS. Results from uniaxial compression tests showed that the amount of iron sand and the type of the binder influences the UCS, as well as content values of fines and porosity. These results demonstrated the possibility for a part of Fe-sand to be deposited together with the tailings sand to increase UCS values for the CPB samples, which will be beneficial for both mining operation and environmental protection.

  • 222.
    Karim, Kamal
    et al.
    Sulaimani University.
    Sissakian, Varoujan
    Consultant Geologist, Erbil.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Effect of the Sun Radiation on the Asymmetry of Valleys in Iraqi Zagros Mountain Belt (Kurdistan Region)2014Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 4, nr 2, s. 23-32Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The geomorphological feature of the valley's asymmetry is described in the Western Zagros in Iraqi Kurdistan; in terms of facing of the valley sides relative to the position of the sun. The asymmetry is represented by steeper northwest facing valley sides; as compared to the southeast facing sides. This feature shows clear valley's asymmetry in cross section is a new geomorphological characteristic for the Western Zagros Mountain Belt. The asymmetry of valleys, in the present study, is proved to exist in different rock types and areas, which is developed by more chemical weathering of one facing sides relative to the other side. The weathering is attributed to the remaining of the moisture for longer time than the southeastern sides, which are stroke by sun radiation for longer time and are dried more rapidly. A simple method was established for indicating the steeper side of the valleys. The method consists of drawing two parallel lines across the photo of the valley, then connecting the bottom of the valley with the left and right deflection points on the inter-valleys ridges by lines. Finally the angles between the lower horiozontal line and inclined lines are measured, which indicates the asymmetry of the valleys.

  • 223.
    Knutsson, Roger
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Bjelkevik, Annika
    Tailings Consultants Scandinavia AB.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Importance of tailings properties for closure2014Konferansepaper (Fagfellevurdert)
  • 224.
    Knutsson, Roger
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Bjelkevik, Annika
    Tailings Consultants Scandinavia AB.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Slope stability in landform design2016Inngår i: Mine Closure 2016 / [ed] A.B. Fourie; M. Tibbett, Perth: Australian Centre for Geomechanics, 2016Konferansepaper (Fagfellevurdert)
  • 225.
    Knutsson, Roger
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Benefits of Advanced Constitutive Modeling when Estimating Deformations in a Tailings Dam2018Inngår i: Journal of Earth Sciences and Geotechnical Engineering, ISSN 1792-9040, E-ISSN 1792-9660, Vol. 8, nr 1, s. 1-19Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Behavior of tailings dams are often controlled in dam surveillance programs where horizontal deformation is one of the key aspects. When evaluating field data, there is a necessity for comparison with anticipated deformations in order to relate field behavior to dam stability. With numerical modeling, these predictions can be made. This paper presents a case where horizontal deformations in a tailings dam have been simulated for a six-year period, using two-dimensional finite element modeling. Yearly dam raises have been simulated as staged constructions according to activities at site. Tailings materials have been simulated with an elasto-plastic constitutive model with isotropic hardening, called Hardening Soil and the conventional linear-elastic, perfectly plastic Mohr-Coulomb model. Soil parameters used for input were calibrated to laboratory data. Results from simulations were compared with data obtained in situ by a slope inclinometer. Results obtained by the Hardening Soil model indicate good agreement with respect to field measurements. However, this was not reached with the Mohr-Coulomb model. The results presented indicate benefits by using an advanced constitutive model for tailings in order to estimate in situ deformations in a tailings dam. The methodology presented can be used for prediction of future deformations, in order to relate the dam behavior to its stability. This is important in dam safety assessment, and will lead to a better understanding of the dam safety, being of great importance for the dam owner and the society in general.

  • 226.
    Knutsson, Roger
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Stability considerations for thickened tailings due to freezing and thawing2016Inngår i: Paste 2016: Proceedings of the 19th International Seminar on Paste and Thickened Tailings / [ed] Sergio Barrea & Richard Jewell, Santiago: GECAMIN, 2016, s. 567-577Konferansepaper (Fagfellevurdert)
  • 227.
    Knutsson, Roger
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    The use of numerical modelling in alert level set-up for instrumentation in tailings dams2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In dam safety operations for tailings dams, instrumentation has a major role. High pore-water pressure or large deformations can both be observed with good monitoring programs, and are covered in many dam safety guidelines. A key aspect when evaluating field data is the way to compare values with expected dam behavior (including a certain safety margin). This is needed in order to determine the safety of a dam, but there is lack of methods for this in the dam industry. With the use of finite element modeling, the behavior and stability of tailings dams can be simulated. Simulated behavior can be used in dam safety operations, where field data is compared with numerical results. In this paper, a case study is presented where a method for instrumentation alarm-level set-up is proposed.

  • 228.
    Knutsson, Roger
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Geothermal study to explain man-made permafrost in tailings with raised surface2018Inngår i: Environmental Earth Sciences, ISSN 1866-6280, E-ISSN 1866-6299, Vol. 77, nr 7, artikkel-id 288Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Deposition of mine tailings in a cold climate requires precautions as temporary sub-zero temperatures can imply considerable consequences to the storage due to creation of permafrost. The risk of creating man-made permafrost lenses due to tailings deposition exists even in regions with no natural permafrost, as material being frozen during winter might not fully thaw by the following summer. When such frozen layers thaw during later longer warmer periods, excess pore water pressure and large settlements might develop. Such implications close to the dam structure have to be avoided and therefore the risk of generating permafrost should be reduced. This paper describes a geothermal model for one-dimensional heat conduction analysis. The model is able to simulate the temperature profile in tailings where the surface elevation is constantly increased due to deposition. At the tailings surface, the boundary condition is the air temperature changing over time during the year. Air temperatures, tailings deposition schedule and tailings properties are given as input to the model and can easily be changed and applied to specific facilities. The model can be used for tailings facilities in cold regions, where the effects of tailings deposition on the temperature regime are of interest. Findings can improve tailings management by explaining man-made permafrost generation. The model can also aid in setting up appropriate deposition schedules and to prevent generation of permafrost layers.

  • 229.
    Knutsson, Roger
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Viklander, Peter
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laue, Jan
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    How to avoid permafrost while depositing tailings in cold climate2018Inngår i: Cold Regions Science and Technology, ISSN 0165-232X, E-ISSN 1872-7441, Vol. 153, s. 86-96Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Managing tailings deposition in cold climate requires specific measures not to create permafrost. The risk of generating permafrost due to tailings deposition exists even in regions where permafrost would naturally not occur. Material being frozen during winter might not fully thaw in the following summer due to added height of the tailings on the surface. Such embedded layers of permafrost should be avoided especially close to tailing dams. Main reasons are to prevent impermeable layers in tailings facilities, and to reduce the risk of having implications if such layers thaw during warmer summers causing increase in pore water pressure, reduced effective stress, and increased water content.

    This paper presents a numerical study on the effects of tailings deposition in cold regions in relation to the potential formation of permafrost. Various deposition rates, schedules and tailings properties were evaluated. One-dimensional heat conduction analyses were performed with a temperature scenario representing a mine district in northern Sweden. Results show, that the thickness of permafrost layers increase with increased deposition rate and with increased water content. It was also shown that wet and loose tailings must be deposited in short periods during summer to avoid permafrost generation. In the case of dry and dense tailings more time is available for deposition in order not to cause aggradation of permafrost in the deposit.

    These findings can help mining operation to set up deposition schedules for tailings facilities in cold climate. For known tailings properties, results can be used to identify periods of the year when, and how much, tailings can be deposited in critical areas of a deposit in order to avoid permafrost formation.

  • 230.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Aktivitet: Transportforum 20092009Konferansepaper (Annet (populærvitenskap, debatt, mm))
  • 231.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Analys av tjällossningsförloppets inverkan på hållfastheten i skiktad jord1987Rapport (Annet vitenskapelig)
  • 232.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Anläggningsverksamhet vid permafrost1985Rapport (Annet vitenskapelig)
  • 233.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    En långtidsstudie av "Wavinbrunnens" beteende i tjällyftande jord: deformationer efter 13 år i jorden1995Rapport (Annet vitenskapelig)
  • 234.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    En teoretisk modell för beräkning av porvattentryck och sättningar i tinande jord1983Rapport (Annet vitenskapelig)
  • 235.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Field study of instrumented guillies and manholes in frost-susceptible soils1982Inngår i: Proceedings of the Third International Symposium on Ground Freezing, 22 - 24 June 1982, US Army Corps of Engineers, Cold Regions Research and Engineering Laboratory, Hanover, New Hampshire, USA / [ed] Donna R. Murphy, Hanover, NH: Cold regions research and engineering laboratory , 1982, s. 367-374Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In Scandinavia, a lot of manholes and gullies, designed for the drainage of rain water, get damaged during winter due to frost action mainly because of the heave of frost susceptible backfill. The concrete rings are pulled apart and the joints between the rings are opened. When thawing starts, water and soil flows into the gullies through the opened joints and the inflowing material prevents the rings from returning to their original positions. In order to study the behavior of manholes and gullies with and without a newly invented rubber sleeve mounted over the joints, a field test was performed during the winter 1980/81 in Lulea, Sweden. The paper describes the instrumentation installed as well as the results obtained

  • 236.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Field study of instrumented gullies and manholes in frost-susceptible soils1984Rapport (Annet vitenskapelig)
  • 237.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Fältstudie av rännstensbrunnar och nedstigningsbrunnar försedda med fogskydd1982Rapport (Annet vitenskapelig)
  • 238.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Ground Freezing 97: frost action in soils : proceedings of the International Symposium on Ground Freezing and Frost Action in Soils / Luleå / Sweden / 15-17 April 19971997Collection/Antologi (Annet vitenskapelig)
  • 239.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hävning och sättning till följd av frysning invid markförlagda kollektorslangar1983Rapport (Annet vitenskapelig)
  • 240.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Hållfasthet/bärighet i tinande tjäle1985Rapport (Annet vitenskapelig)
  • 241.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Inverkan av cyklisk frysning på lerors konsistensgränser1984Rapport (Annet vitenskapelig)
  • 242.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Jordmaterials värmetekniska egenskaper: kompendium1985Rapport (Annet vitenskapelig)
  • 243.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laboratorieundersökning av värmeledningsförmåga och kompressionsegenskaper hos hyttsten1979Rapport (Annet vitenskapelig)
  • 244.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Laboratorieundersökning av värmeledningsförmåga och kompressionsegenskaper hos slaggpellets1979Rapport (Annet vitenskapelig)
  • 245.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Nordiskt seminarium om tjälforskning: Helsingfors, november 1986 : föredrag och diskussionsinlägg1987Rapport (Annet vitenskapelig)
  • 246.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Permafrost i Norgevägen1980Inngår i: Byggmästaren, ISSN 0007-7550, nr 10, s. 8-11Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 247.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Påverkas packningsgrad hos grovkornig jord av tjäle?1999Inngår i: Proceedings VTI:s Forskardagar, Transportforum '99, 1999Konferansepaper (Annet vitenskapelig)
  • 248.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Rännstensbrunnar och nedstigningsbrunnar försedda med fogskydd: förstudie1982Rapport (Annet vitenskapelig)
  • 249.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Soil behavior at freezing and thawing1998Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [sv]

    Avhandlingens första del behandlar en teoretisk beräkningsmodell för tjällyftning samt studier av dess noggranhet i olika situationer. Tjällossningsförloppet analyseras och studeras genom noggranna mätningar av porvattentryckens fördelning i tid och rum. Porvattentrycksutvecklingen kopplas till läget av islinserna i jorden, som detekteras med hjälp av röntgenteknik. Avhandlingens andra del belyser hur frusen jord kan packas och vad deformationerna i sådan jord blir då den tinar. Beräkningar av kompressionen i samband med upptining jämförs med resultat från såväl laboratorieförsök som uppföljningar i fält. Strukturella förändringar i jorden till följd av frysning och tining belyses också.

  • 250.
    Knutsson, Sven
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Stresses in the hydraulic backfill from analytical calculations and in-situ measurements1981Inngår i: Application of rock mechanics to cut and fill mining: proceedings of the Conference on the application of rock mechanics to cut and fill mining, organized by the Departments of rock mechanics and soil mechanics, University of Luleå ... held at the University of Luleå, Sweden, from 1 to 3 June, 1980 / [ed] Ove Stephansson; Michael J. Jones, London: The Institution of Mining and Metallurgy , 1981, s. 261-268Konferansepaper (Fagfellevurdert)
2345678 201 - 250 of 439
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