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5. Atterberg limits in relation to other properties of fine-grained soilsBojana Dolinar, Stanislav Škrabl, 2013, izvirni znanstveni članek Opis: In soil mechanics the Atterberg limits are the most distinctive and the easiest property of fine-grained soils to measure. As they depend on the same physical factors as the other mechanical properties of soils, the values of the liquid and plastic limits would be a very convenient basis for their prediction. There are many studies concerning the use of the Atterberg limits in soil mechanics; however, their results vary considerably and are not generally applicable. This paper explains the main reasons for the different conclusions in these studies, which do not take into account the following: a) the water in fine-grained soils appears as interparticle and interaggregate pore water as well as adsorbed water onto the surfaces of clay minerals; b) the physical properties of fine-grained soils depend on the quantity of pore water only, because the adsorbed water is tightly tied on the clayʼs external and internal surfaces and thus cannot influence to them; c) the quantity of adsorbed water on the external surfaces of the clay minerals in soils depends mostly on the size and the quantity of the clay minerals, while the interlayer water quantity depends mostly on the quantity and the type of the swelling clay minerals in the soil composition and their exchangeable cations. From this it follows that for swelling and non-swelling soils, the uniform relationships between the Atterberg limits (which represent the total quantity of pore water and the adsorbed water onto the external and internal surfaces of clay minerals) and other physical properties does not exist. This paper presents some possibilities for the use of the Atterberg limits in predicting the soilʼs other properties for non-swelling and limited-swelling soils.
Ključne besede: Atterberg limits, specific surface area, undrained shear strength, compressibility, hydraulic conductivity
Objavljeno v DKUM: 14.06.2018; Ogledov: 1401; Prenosov: 93
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6. Analyses of the suspended-load sedimentation process and its dynamics in reservoirs with high daily oscillationsHelena Vrecl-Kojc, Bojana Dolinar, Roman Klasinc, Ludvik Trauner, 2008, izvirni znanstveni članek Opis: The river water pumped into reservoirs with high daily oscillations, e.g. at pumping hydroelectric power plants, contains different amounts of suspended load depending on the time period and the riverćs discharge. This paper presents an analysis of the suspended-load sedimentation process that is based on the interaction between the sedimentation, i.e., the settling, velocity and the motion of the water. The settling velocity of spherical particles in the presence of a buoyancy force is a function of the particle size. Laboratory investigations of the suspended material from the river-watersamples have determined the ratio between the particle size and the concentration of suspended material with respect to the river discharge, the ratio between the concentration of suspended material in the water and the discharge, and the relationship between the concentration of suspended material and the discharge of water, which is for the first time expressed as an exponential function. The motion of the water in the reservoirs with high daily oscillations is solved by the three-dimensional modeling of the liquid streams. The evaluation of the results is presented for the case of the planned Kozjak pumping hydroelectric power plant on the River Drava.
Ključne besede: suspended load, water motion, sedimentation, sedimentation transport, pumped hydroelectric power plant, reservoir
Objavljeno v DKUM: 05.06.2018; Ogledov: 2016; Prenosov: 65
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7. Analysis of concentration and sedimentation of suspended load in the reservoirsHelena Vrecl-Kojc, Bojana Dolinar, Roman Klasinc, Ludvik Trauner, 2008, izvirni znanstveni članek Opis: This paper deals with the sedimentation of suspended load in the reservoirs. As an example the reservoir of the hydroelectric power plant Boštanj on the Sava River is shown. The objective of the described studies was to determine the quantity and type of deposited material in the reservoir during the selected time period. For this purpose, the mineral and chemical composition, and the concentration and the particle size of the suspended load at the intake of the water into the reservoir and at its outflow were examined. In order to determine the concentration of the suspended load, 24 water samples from the area of the intake and outflow from the reservoir were taken. At the same time the discharge of the Sava River was measured. Solid particles were removed from the water with the help of sedimentation and in the final stage of water evaporation. The results of the studies showed that the concentration of the suspended material was changing in relation to the location and the flow rate of the water. This ratio can be described with an exponential function.
In suspended load composition carbonates, muscovite/illite and quartz dominate; however, chlorite was also found, as well as small quantities of plagioclase and organic detritus. With regard to the size of the particles the examined samples are classified as silt.
It was determined that the concentration of the suspended load, at the same flow rate of water, at the intake into the reservoir is larger than at the outflow. The difference is represented by the material that was sedimented in the reservoir due to the decreased speed of the water as a result of the river's impoundment. A comparison of the composition of the samples from both collection sites showed that at the outflow site of the water from the reservoir there is a somewhat smaller share of carbonate grains and heavy minerals than at the intake site, and a higher content of organic detritus and clay particles can also be observed. Considering the actual discharge of water in the period between July 2006 and July 2007 and the examined ratio between the flow rate of the water and the quantity of suspended and deposited material, the total quantity of sedimented material in this period was estimated.
Ključne besede: suspended load, sedimentation, sediment transport, water storage reservoir
Objavljeno v DKUM: 05.06.2018; Ogledov: 2091; Prenosov: 83
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8. Undrained shear strength of saturated cohesive soils depending on consolidation pressure and mineralogical propertiesBojana Dolinar, 2004, izvirni znanstveni članek Opis: The relationship between the water content and the undrained shear strength of finely grained soils can be described with a nonlinear function in which the type of soils is determined by two parameters. These parameters depend primarily on the size of clay minerals, their quantity in soil composition and the interlayer water quantity in expanding clay minerals. This article asserts that there exists also the exactly defined relationship also between the water content and consolidation pressure. In the function describing this relationship, the type of soil is determined by two parameters. They can be expressed depending on the same mineralogical properties of soils as the values of parameters in the function showing the relationship between the water content and the undrained shear strength. These findings allow us to express the ratio between undrained shear strength and consolidation pressure depending on mineralogical properties of soils.
Ključne besede: soil mechanics, properties of soils, clays, specific surface, undrained shear strenght, compressibility
Objavljeno v DKUM: 15.05.2018; Ogledov: 1513; Prenosov: 112
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9. Acta geotechnica Slovenica2004, revija Opis: Acta geotechnica Slovenica aims to play an important role in publishing high-quality, theoretical papers from important and emerging areas that will have a lasting impact on fundamental and practical aspects of geomechanics and geotechnical engineering.
Acta geotechnica Slovenica publishes papers from the following areas: soil and rock mechanics, engineering geology, environmental geotechnics, geosynthetic, geotechnical structures, numerical and analytical methods, computer modelling, optimization of geotechnical structures, field and laboratory testing.
The journal is published twice a year.
Ključne besede: scientific journals, geomechanics, geotechnical engineering
Objavljeno v DKUM: 15.05.2018; Ogledov: 3091; Prenosov: 107
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10. Analiza vpliva življenjskega cikla proizvodnje aluminijevih drogov na okoljeAnja Selinšek, 2018, magistrsko delo Opis: V magistrskem delu smo s pomočjo delovnega okolja družbe Talum iz Kidričevega na konkretnem primeru proizvodnje aluminijevih drogov prikazali uporabo metode analize življenjskega cikla. V teoretičnem delu magistrskega dela je predstavljen razvoj metode in njen podrobnejši opis s pomočjo standardne osnove. Skozi razčlenjen proizvodni proces smo opisali vsak korak proizvodnje posebej ter hkrati razložili njegove bistvene značilnosti. V raziskovalnem delu magistrskega dela smo na podlagi veljavnih standardov zbrali in analizirali informacije o vhodnih in izhodnih tokovih posamezne procesne enote. Dobljene informacije smo zajeli v programu GaBi Education ter tako številčno ovrednotili izbrane kazalnike obremenjevanja okolja. V sklepnem delu magistrskega dela je sledil še poskus okoljskega optimiziranja z modeliranjem različnih scenarijev transportnih poti uvoza osnovne surovine – glinice.
Ključne besede: metoda analize življenjskega cikla, trajnostnost, proizvodnja aluminijevih drogov, vplivi na okolje, kazalniki okoljskega vpliva
Objavljeno v DKUM: 22.02.2018; Ogledov: 1894; Prenosov: 55
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