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1دورية أكاديمية
المؤلفون: Lemenkova, Polina
المصدر: Mercator (Fortaleza). January 2021 20
مصطلحات موضوعية: GMT, Pacific Ocean, Tectonics, Mapping, Cartography, GIS, Data
الوصف: The paper presents spatial analysis of the geological settings and topographic structure of the Pacific Ocean by Generic Mapping Tools (GMT). Its tectonic and geomorphic features have complex character and include, among others, trenches, ridges, East Pacific Rise, basins, fracture zones, rifts, rises, fault systems. Such topographic complexity results in the variability of the seafloor fabric and sedimentation reflecting correlations between the tectonic geomorphic markers and bathymetry. The methodology of this paper is based on the advanced cartographic toolset GMT which utilizes a shell scripting approach using a variety of modules. The tectonics showed strong correlation with the seafloor topography, and weaker correlation with sedimentation, which is influenced by geomorphology, gravity anomalies and bathymetry. The paper contributes to the oceanographic and geologic studies of the Pacific Ocean and methodology of GMT.
وصف الملف: text/html
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المؤلفون: Lindh, Per, Lemenkova, Polina
المصدر: Transport and Telecommunication. 24(1):73-82
مصطلحات موضوعية: cement, driveway, fly ash, lime, road base, slag, stabilization, Teknik, Samhällsbyggnadsteknik, Geoteknik, Engineering and Technology, Civil Engineering, Geotechnical Engineering
الوصف: Clay soils can cause significant distress in road construction due to their low strength. Stabilizing such soil improve with binder agents prior to the geotechnical works can significantly its performance and ensure safety and stability of roads while exploitation. This research envisaged the use of five different binders (lime, energy fly ash, bio fly ash, slag, cement) as an additive stabilizing agents to improve the strength parameters of soil as required in engineering industry standards. The variations of strength was assessed using measurements of P-wave velocity of the elastic waves propagating through soil specimens stabilized by different combination of binders. Measurements were performed on 28th day of soil treatment. The best effects of added binders were noted in the following combinations: cement / energy fly ash / bio fly ash (P-waves >3100 m/s), followed by combination lime / energy fly ash / GGBFS (P-waves >2800 m/s) and cement / lime / energy fly ash (P-waves >2700 m/s). Adding lime is effective due to its fixation and chemical bond with particles. The study contributes to the industrial tests on soil strength for constructing roadbed.
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المؤلفون: Lindh, Per, Lemenkova, Polina
المصدر: Archives of Acoustics. 48(3):325-346
مصطلحات موضوعية: cement, civil engineering, compressive strength, lime, seismic waves, soil stabilization, Teknik, Samhällsbyggnadsteknik, Geoteknik, Engineering and Technology, Civil Engineering, Geotechnical Engineering
الوصف: In this research project, the measurements of the ultrasonic P- and S-waves and seismic cone penetration testing (CPT) were applied to identify subsurface conditions and properties of clayey soil stabilized with lime/cement columns in the Stockholm Norvik Port, Sweden. Applied geophysical methods enabled to identify a connection between the resistance of soil and strength in the stabilized columns. The records of the seismic tests were obtained in the laboratory of Swedish Geotechnical Institute (SGI) through estimated P- and S-wave velocities using techniques of resonance frequency measurement of the stabilized specimens. The CPT profiles were used to evaluate the quality of the lime/cement columns of the reinforced soil by the interpretation of signals. The relationship between the P- and S-waves demonstrated a gain in strength during soil hardening. The quality of soil was evaluated by seismic measurements with aim to achieve sufficient strength of foundations prior to the construction of the infrastructure objects and industrial works. Seismic CPT is an effective method essential to evaluate the correct placement of the CPT inside the column. This work demonstrated the alternative seismic methods supporting the up-hole technology of drilling techniques for practical purpose in civil engineering and geotechnical works.
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المؤلفون: Lindh, Per, Lemenkova, Polina
المصدر: Archives of Mining Sciences. 68(2):319-334
مصطلحات موضوعية: cement, civil engineering, lime, slag, soil, UCS, Teknik, Samhällsbyggnadsteknik, Geoteknik, Engineering and Technology, Civil Engineering, Geotechnical Engineering
الوصف: This paper aims to evaluate the effects of blended binders on the development of strength in moraine soils by optimising the proportion of several binders. We tested three types of soil as a mixture of moraine soils: A (sandy clay), B (clayey silt) and C (silty clay), collected in southern Sweden. The soil was compacted using a modified Proctor test using the standard SS-EN 13286-2:2010 to determine optimum moisture content. The particle size distribution was analysed to determine suitable binders. The specimens of types A, B and C, were treated by six different binders: ordinary Portland cement (OPC); hydrated lime (Ca(OH)2); ground granulated blast furnace slag (GGBFS) and their blends in various proportions. The strength gain in soil treated by binders was evaluated by the test for Unconfined Compressive Strength (UCS) against curing time. For soil type A, the strength increase is comparable for most of the binders, with the difference in behaviour in the UCS gain. The OPC/lime, GGBFS and hydrated lime showed a direct correlation, while OPC, OPC/GGBFS and GGBFS/hydrated lime – a quick gain in the UCS by day 28th. After that, the rate of growth decreased. Compared to soil type A, Ca(OH)2 performs better on the stabilisation of soil type B. Besides, the hydrated lime works better on the gain of the UCS compared to other binders. The GGBFS/Ca(OH)2 blend shows a notable effect on soil type A: the UCS of soil treated by Ca(OH)2 performs similarly to those treated by OPC with visible effects on day 90th. Cement and a blend of slag/hydrated lime demonstrated the best results for soil type B. An effective interaction was noted for the blends GGBFS and hydrated lime, which is reflected in the UCS development in soils type A and B. Blended binder GGBFS/hydrated lime performs better compared to single binders.
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المؤلفون: Lindh, Per, Lemenkova, Polina
المصدر: Acta Polytechnica. 63(2):140-157
مصطلحات موضوعية: binder, OPC, simplex experimental design, Soil stabilisation, statistical analysis, Teknik, Samhällsbyggnadsteknik, Geoteknik, Engineering and Technology, Civil Engineering, Geotechnical Engineering
الوصف: In this paper, we present a new framework for improving soil strength using an advanced method of engineering statistics. The materials included clay till collected in Yttre Ringvägen, southern Sweden. Binders included quicklime, slag and ordinary Portland cement used as pure binders and blended mixtures. We first applied the Response Surface Methodology techniques aimed at binder blend optimisation: 1) Central Composite Design; 2) Box-Behnken Design; 3) Simplex Lattice Design. The Pareto charts were presented for modelling responses from tests with different binders and estimating their effects on soil strength. Finally, to examine the variables important for soil stabilisation, we also evaluated the effect of the amount of binder and the interaction between cement/lime/slag in different ratios: 30-50-20 %; 50-50-0 %; 100-0-0 % The paper highlights the major opportunities and challenges of engineering statistics as a cross-cutting research direction for the issues of civil engineering.
URL الوصول: https://lup.lub.lu.se/record/c48a6cbe-ec91-4af8-82ab-1fae53d479d9
http://dx.doi.org/10.14311/AP.2023.63.0140 -
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المؤلفون: Lindh, Per, Lemenkova, Polina
المصدر: Ecological Chemistry and Engineering S. 29(4):537-552
مصطلحات موضوعية: Lantbruksvetenskap och veterinärmedicin, Lantbruksvetenskap, skogsbruk och fiske, Markvetenskap, Agricultural Sciences, Agricultural Science, Forestry and Fisheries, Soil Science
الوصف: Leaching behaviour is an important evidence of soil quality. The assessment of leaching of heavy metals from the contaminated soil is vital for environmental applications. However, leaching may differ in soil stabilised by various ratios of binders. In this study we measured leaching behaviour of soil contaminated by As, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, Zn, methyl Hg, aliphatic compounds of hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and dissolved organic carbon (DOC). To evaluate leaching of these substances we tested the effects of changed amount of binder (120 kg and 150 kg) and binder ratios (70/30 %, 50/50 % and 30/70 %) added to soil samples. Soil was dredged from several stations in Ostrand area, SCA Sundsvall Ortvikens Pappersbruk. The results demonstrated a systematically decreasing leaching with the increased slag. The contribution of this research include: (i) devising systematic approach to extract information on leaching from stabilised soil collected from the coastal area of Bothnian Bay, (ii) developing a workflow for stabilising soils by various combination of Portland cement Basement CEM II/A-V (SS EN 197-1) and ground granulated blast furnace slag (GGBFS), Bremen type (SS EN 15167-1), (iii) determining water ratio and density for the untreated and stabilised soil and performing comparative analysis, (iv) evaluating chemical content of pollutants and toxic elements in the aggregated soil samples. Treatment of the contaminated soil by binders improved its parameters by the increased strength and decreased leaching of heavy metals and toxic elements.
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7دورية أكاديمية
المؤلفون: Lemenkova Polina
المصدر: Die Bodenkultur, Vol 74, Iss 1, Pp 49-64 (2023)
مصطلحات موضوعية: sahel, remote sensing, geoinformation, cartography, scripting language, sahelzone, fernerkundung, kartografie, programmiersprache, Environmental sciences, GE1-350
الوصف: Lake Chad, situated in the semi-arid region of African Sahel, plays a vital role in hydrogeological balance of regional ecosystems. It presents an essential water source and provides a habitat for rare wildlife species including migrating waterbirds. However, the lake has shrunk significantly since the 1960s and has continued to reduce in size and extent during recent decades. Trends in drying and shrinking of Lake Chad are caused by environmental factors and changed climate. The desiccation of the lake is threatening environmental sustainability. This study focused on identification of changes in the Chad Lake area, wetland extent, and associated land cover types. The methods include the Geographic Resources Analysis Support System (GRASS) Geographic Information System (GIS) for remote sensing data classification. The maximum likelihood discriminant analysis classifier was applied for analysis of multispectral Landsat 8–9 OLI/TIRS images in 2013, 2017, and 2022. Detected changes in land cover types reflect variations in water balance and wetland area and extent around Lake Chad over recent decades. Cartographic scripting tools of GRASS GIS provide an efficient method of digital image processing for monitoring endorheic lakes of Central Africa. GRASS GIS methods provide an opportunity to automatically classify Earth observation data with cartographic scripts for environmental monitoring.
وصف الملف: electronic resource
Relation: https://doaj.org/toc/2719-5430
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المؤلفون: Lindh, Per, Lemenkova, Polina
المصدر: Civil and Environmental Engineering. 18(2):726-735
مصطلحات موضوعية: Cement, Compressive strength, Fly ash, Lime, Slag, Teknik, Samhällsbyggnadsteknik, Geoteknik, Engineering and Technology, Civil Engineering, Geotechnical Engineering
الوصف: In this study, the stabilization process is introduced to a clayey expansive soil collected in southern Sweden. The tests examined strength parameters of expansive soil stabilized by different binders using combination of both traditional binders (cement and lime) and alternative materials (slag Merit 5000, fly ash from SCA Lilla Edet and fly ash from coal combustion, ISO certified). The practical goal was to find a binder mixture that is optimized for soil stabilization with respect to technical properties of stabilizing agent as an inert ballast material. The strength of soil stabilized by various binders was examined by velocity of the P-waves propagating through specimens. The results show that introducing slag Merit 5000 as an admixture to cement and lime is an effective approach in enhancing strength properties in weak soil, which increases bearing capacity of soil for planned construction works. The results also shown that a mixture of lime and bio ash yields a better effect in the stabilization of a clay. Soil stabilized with cement, cement/slag and lime/slag becomes resistant to freeze-thaw cycles, which is crucial for construction of roads and building foundations.
URL الوصول: https://lup.lub.lu.se/record/73f96b0d-24eb-4d60-b00f-769718972bd2
http://dx.doi.org/10.2478/cee-2022-0067 -
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المؤلفون: Lindh, Per, Lemenkova, Polina
المصدر: Archive of Mechanical Engineering. 69(4):667-692
مصطلحات موضوعية: Cement, Compactness, Compressive strength, Permeability, Porosity, Teknik, Samhällsbyggnadsteknik, Geoteknik, Engineering and Technology, Civil Engineering, Geotechnical Engineering
الوصف: The study investigates the effect of Portland cement and ground granulated blast furnace slag (GGBFS) added in changed proportions as stabilising agents on soil parameters: uniaxial compressive strength (UCS), Proctor compactness and permeability. The material included dredged clayey silts collected from the coasts of Timrå, Östrand. Soil samples were treated by different ratio of the stabilising agents and water and tested for properties. Study aimed at estimating variations of permeability, UCS and compaction of soil by changed ratio of binders. Permeability tests were performed on soil with varied stabilising agents in ratio HW LB (high water / low binder) with ratio 70/30%, 50/50%, and 30/70%. The highest level of permeability was achieved by ratio 70/30% of cement/slag, while the lowest – by 30/70%. Proctor compaction was assessed on a mixture of ash and green liquor sludge, to determine optimal moisture content for the most dense soil. The maximal dry density at 1.12 g/cm3 was obtained by 38.75 % of water in a binder. Shear strength and P-wave velocity were measured using ISO/TS17892-7 and visualised as a function of UCS. The results showed varying permeability and UCS of soil stabilised by changed ratio of CEM II/GGBS.
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المؤلفون: Lindh, Per, Lemenkova, Polina
المصدر: Gospodarka Surowcami Mineralnymi / Mineral Resources Management. 38(2):147-168
مصطلحات موضوعية: Baltic Sea, civil engineering, geotechnical engineering, marine pollution, soil, Teknik, Samhällsbyggnadsteknik, Geoteknik, Engineering and Technology, Civil Engineering, Geotechnical Engineering, Naturvetenskap, Geovetenskap och miljövetenskap, Miljövetenskap, Natural Sciences, Earth and Related Environmental Sciences, Environmental Sciences
الوصف: This paper presents an experimental study on the leaching of heavy metals, toxic chemicals and persistent organic pollutants (POPs) – PAH, PCB and HCB – from soil dredged from the coastal area of Västernorrland in northern Sweden. The soil was stabilized with cement/slag. Samples were subjected to modified surface leaching and shake tests using technical standards of the Swedish Geotech-nical Institute (SGI). The experiments were performed using different blends of binding agents (30/70, 50/50, 70/30) and binder quantities (120 and 150 kg/m3) to analyze their effects on leaching. Soil prop-erties, tools, and workflow are described. Binders included Portland cement and ground granulated blast furnace slag (GGBFS). Samples were tested to evaluate the min/max contents of pollutants (µg/l) for heavy metals (As, Ba, Pb, Cd, Co, Cu, Cr, Hg, Mn, Mo, Ni, S, V, Zn) and the hydrocarbon fraction index in the excess water. The leaching of heavy metals and POPs was assessed in sediments after the addition of the binder. The comparison was made against the two mixes (cement/slag in 30/70% and high/low binder with low/high water ratio). The results showed that 70% slag decreases the leaching of heavy metals and POPs. The equilibrium concentrations of DOC and heavy metals at L/S 10 (μg/l) were measured during the shake experiments to compare their levels in the groundwater that was used as a leachate. The leached content was assessed at L/S 10 in the upscaling experiments using four samples for PAH, PCB and various fractions of hydrocarbons: C10–C40, C10–C12, C12–C16 and C35–C40. The shake test showed a decrease in the leaching of heavy metals and POP substances from the soil subjected to stabilization by a higher amount of slag added as a binder. A binder blend with 30% cement and 70% of GGBFS showed the best performance.
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