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EN
In the present research, a scripting cartographic technique for the environmental mapping of Ethiopia using climate and topographic datasets is developed. The strength of the Generic Mapping Tools (GMT) is employed for the effective visualisation of the seven maps using high-resolution data: GEBCO, TerraClimate, WorldClim, CRUTS 4.0 in 2018 by considering the solutions of map design. The role of topographic characteristics for climate variables (evapotranspiration, downward surface shortwave radiation, vapour pressure, vapour pressure deficit and climatic water deficit) is explained. Topographic variability of Ethiopia is illustrated for geographically dispersed and contrasting environmental setting in its various regions: Afar, Danakil Depression, Ethiopian Highlands, Great Rift Valley, lowlands and Ogaden Desert. The relationships between the environmental and topographic variables are investigated with aid of literature review and the outcomes are discussed. The maps are demonstrated graphically to highlight variables enabling to find correlations between the geographic phenomena, their distribution and intensity. The presented maps honor the environmental and topographic data sets within the resolution of the data. Integration of these results in the interpretation maps presented here brings new insights into both the variations of selected climate variables, and the topography of Ethiopia.
EN
This article analyzes topographical and geological settings in the Japan Archipelago for comparative raster data processing using GRASS GIS. Data include bathymetric and geological grids in NetCDF format: GEBCO, EMAG2, GlobSed, marine free-air gravity anomaly and EGM96. Data were imported to GRASS by gdalwarp utility of GDAL and projected via PROJ library. Methodology includes data processing (projecting and import), mapping and spatial analysis. Visualization was done by shell scripting using a sequence of GRASS modules: ‘d.shade’ for relief mapping, ‘r.slope.aspect’; for modelling based on DEM, ‘r.contour’ for plotting isolines, ‘r.mapcalc’ for classification, ‘r.category’ for associating labels, and auxiliary modules (d.vect, d.rast, d.grid, d.legend). The results of the geophysical visualization show that marine free-air gravitational anomalies vary in the Sea of Japan (–30 to above 40 mGal) reflecting density inhomogeneities of the tectonic structure, and correlating with the geological structure of the seafloor. Dominating values of geoid model are 30–45 m reflecting West Pacific rise, determined by deep density inhomogeneities associated with the mantle convention. Sediment thickness varies across the sea reflecting its geological development with density of 2 km in its deepest part and thinner in central part (Yamato Rise). The aspect map and reclassified map express gradient of the steepest descent.
EN
The applications of the machine learning and programming approaches in cartography has been increasing in recent years. This paper presents a case study of the scripting techniques used for cartographic mapping using Generic Mapping Tools (GMT) and R language (raster and tmaps packages). The aim of the study is environmental mapping of Ghana. The materials include high-resolution raster grids: topography by the General Bathymetric Chart of the Oceans (GEBCO), climate and environmental datasets (TerraClimate) and Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) for geomorphometric analysis (slope, aspect, hillshade and elevations). The methodology includes code snippets commented and explained with details of scripts. It is argued that using consolebased scripting tools for mapping is effective for cartographic workflow due to the logical structure and repeatability of scripts. The results include eight new thematic maps of Ghana performed using scripting approach inGMTscripting toolset and R language for quantitative and qualitative environmental assessment. Maps show correlations between the landforms of Ghana and certain environmental variables (drought index and soil moisture) showing the effects of the topographic relief on the distribution of the continuous geographic fields. These varied in several geographically distinct regions of Ghana: Ashanti (Kumasi), Volta, Savannah, coastal and northern regions. Demonstrated maps show that scripting method works effectively on a wide range of geosciences including environmental, topographic and climate studies. In such a way, this paper contributes both to the regional studies of Ghana and development of cartographic techniques.
EN
The paper concerns GMT application for studies of the geophysical and geomorphological settings of the Weddell Sea. Its western part is occupied by the back-arc basin developed during geologic evolution of the Antarctic. The mapping presents geophysical settings reflecting tectonic formation of the region, glaciomarine sediment distribution and the bathymetry. The GlobSed grid highlighted the abnormally large thickness of sedimentary strata resulted from the long lasting sedimentation and great subsidence ratio. The sediment thickness indicated significant influx (>13,000m) in the southern segment. Values of 6,000–7,000 m along the peninsula indicate stability of the sediments influx. The northern end of the Filchner Trough shows increased sediment supply. The topography shows variability -7,160–4,763 m. The ridges in the northern segment and gravity anomalies (>75 mGal) show parallel lines stretching NW-SE (10°–45°W, 60°–67°S) which points at the effects of regional topography. The basin is dominated by the slightly negative gravity >-30 mGal. The geoid model shows a SW-NE trend with the lowest values <18 m in the south, the highest values >20m in the NE and along the Coats Land. The ripples in the north follow the geometry of the submarine ridges and channels proving correlation with topography and gravitational equipotential surface.
EN
Integrated geophysical mapping benefits from visualizing multi-source datasets including gravity and satellite altimetry data using 2D and 3D techniques. Applying scripting cartographic approach by R language and GMT supported by traditional mapping in QGIS is presented in this paper with a case study of Iranian geomorphology and a special focus on Zagros Fold-and-Thrust Belt, a unique landform of the country affected by complex geodynamic structure. Several modules of GMT and ’tmap’ and ’raster’ packages of R language were shown to illustrate the efficiency of the console-based mapping by scripts. Data sources included high-resolution raster grids of GEBCO/SRTM, EGM-2008, SRTM DEM and vector geologic layers of USGS. The cartographic objective was to visualize thematic maps of Iran: topography, geology, satellite-derived gravity anomalies, geoid undulations and geomorphology. Various cartographic techniques were applied to plot the geophysical and topographic field gradients and categorical variations in geological structures and relief along the Zagros Fold-and-Thrust Belt. The structures of Elburz, Zagros, Kopet Dag and Makran slopes, Dasht-e Kavir, Dasht-e Lut and Great Salt Desert were visualized using 3D-and 2D techniques. The geomorphometric properties (slope, aspect, hillshade, elevations) were modelled by R. The study presented a series of 11 new maps made using a combination of scripting techniques and GIS for comparative geological-geophysical analysis. Listings of R and GMT scripting are provided for repeatability.
EN
The paper presents the application of ArcGIS for environmental modelling of the landscapes in northern Iceland (17.00°W–23.00°W, 64.30°N–67.00°N). The aim was to explore the vegetation distribution by NDVI and ISOCLUST classification of the land cover types. Data include the Landsat TM image. Freely available satellite remote sensing data from the Landsat mission have been processed by GIS to deliver information on land cover types from image classification and NDVI vegetation index. Landsat products provide geospatial data on regional scale with moderate temporal (weekly) and spatial (30–10 m) resolution, making them useful for environmental monitoring and landscape studies. The tools include the ArcGIS software used for raster processing. Data processing was performed in the three steps: 1) comparative analysis of the visualized sixteen band combinations to assess the distinguishability of vegetation and other land cover types in colour composites; 2) computed NDVI standardized vegetation index; 3) unsupervised classification of the Landsat TM by the ISOCLUST algorithm. Large glaciers Hofsjökull and Langjökull were detected on various colour composites, and the visibility of the water/land borders is assessed (Blöndulón lake), agricultural areas near the Varmahlíð, vegetated areas around the Akrahreppur municipality. Computing the NDVI and using ISOCLUST by ArcGIS software enabled to distinguish various land cover types and map landscapes in the study area. The computed NDVI shown the presence and condition of vegetation, that is, a relative biomass in the area of northern Iceland. The NDVI was used based on the contrast of the two channels from a multispectral Landsat TM raster data.
EN
The study area is focused on the Kuril–Kamchatka Trench, North Pacific Ocean. This region is geologically complex, notable for the lithosphere activity, tectonic plates subduction and active volcanism. The submarine geomorphology is complicated through terraces, slopes, seamounts and erosional processes. Understanding geomorphic features of such a region requires precise modelling and effective visualization of the high-resolution data sets. Therefore, current research presents a Generic Mapping Tools (GMT) based algorithm proposing a solution for effective data processing and precise mapping: iterative module-based scripting for the automated digitizing and modelling. Methodology consists of the following steps: topographic mapping of the raster grids, marine gravity and geoid; semi-automatic digitizing of the orthogonal cross-section profiles; modelling geomorphic trends of the gradient slopes; computing raster surfaces from the xyz data sets by modules nearneighbor and XYZ2grd. Several types of the cartographic projections were used: oblique Mercator, Mercator cylindrical, conic equal-area Albers, conic equidistant. The cross-section geomorphic profiles in a perpendicular direction across the two selected segments of the trench were automatically digitized. Developed algorithm of the semi-automated digitizing of the profiles enabled to visualize gradients of the slope steepness of the trench. The data were then modelled to show gradient variations in its two segments. The results of the comparative geomorphic analysis of northern and southern transects revealed variations in different parts of the trench. Presented research provided more quantitative insights into the structure and settings of the submarine landforms of the hadal trench that still remains a question for the marine geology. The research demonstrated the effectiveness of the GMT: a variety of modules, approaches and tools that can be used to produce high-quality mapping and graphics. The GMT listings are provided for repeatability.
EN
The study focuses on the Makran Trench in the Arabian Sea basin, in the north Indian Ocean. The area is tectonically active, with a system of ridges and fracture zones morphologically separating the Arabian Sea. The study examined the relationships between the topographic structure of the Makran Trench and the regional settings of the Arabian Sea: geomorphology, sediment thickness, geophysical fields, geology and tectonic lineaments. The methodology is based on the GMT scripting toolset. The spatial analysis includes high-resolution datasets GEBCO, EGM2008, GlobSed and data on tectonics, geology, geophysics, sediment thickness and topographic terrain model visualized by GMT. The paper also defined a way in which the proprietary ESRI data format can be transformed into the freely available GMT geospatial data of the geoid EGM2008 model. The geomorphological modeling included the automatic digitization of 300-km width cross-section profiles of the trench demonstrating its submarine relief. The analysis showed a correlation between the geological and tectonic structures, asymmetric geomorphology and geophysical anomaly fields. Gravity data indicate a crustal structure with anomalies generated by the bending of the lithosphere into the Makran subduction zone and density variations in the mantle reflected on the gravity maps. The gravity correlates with lineaments of the geomorphic structures. Bathymetric analysis revealed the most frequent depth (448 samples) at −3,250 to −3,500 m, followed by intervals: −3,000 to −3,250 m, −2,750 to −3,000 m. The declining continental slope correlates with gradually decreasing depths as equally distributed bins: 124 samples (−2,500 to −2,750 m), 96 (−2,250 to −2,500 m), 86 (−2,000 to −2,250 m). The trench is an asymmetric form with a high steepness on the continental slope of Pakistan and low steepness with a flat valley on the oceanward side. The multi-source data integration is important for seafloor mapping and the geomorphological analysis of oceanic trenches hidden to direct observations. The machine learning methods of GMT and cartographic modeling provide possibilities for the effective visualization of the trench. The comparison of the geomorphology with gravity anomalies, tectonic lineation, geological structures and topographical variations provides more detail to studies of the seafloor in the Arabian Sea.
EN
The author presents a geospatial analysis of the Peru-Chile Trench located in the South Pacific Ocean by the Generic Mapping Tool (GMT) scripting toolset used to process and model data sets. The study goal is to perform geomorphological modelling by the comparison of two segments of the trench located in northern (Peruvian) and southern (Chilean) parts. The aim of the study is to perform automatic digitizing profiles using GMT and several scripting modules. Orthogonal cross-section profiles transecting the trench in a perpendicular direction were automatically digitized, and the profiles visualized and compared. The profiles show variations in the geomorphology of the trench in the northern and southern segments. To visualize geological and geophysical settings, a set of the thematic maps was visualized by GMT modules: free-air gravity anomaly, geoid, geology and bathymetry. The results of the descriptive statistical analysis of the bathymetry in both segments show that the most frequent depths for the Peruvian segment of the Peru-Chile Trench range from -4,000 to -4,200 (827 recorded samples) versus the range of -4,500 to -4,700 m for the Peruvian segment (1,410 samples). The Peruvian segment of the trench is deeper and its geomorphology steeper with abrupt slopes compared to the Chilean segment. A comparison of the data distribution for both segments gives the following results. The Peruvian segment has the majority of data (23%) reaching 1,410 (-4,500 m to -4,700 m). This peak shows a steep pattern in data distribution, while other data in the neighbouring diapason are significantly lower: 559 (-4,700 m to -5,000 m) and 807 (-4,200 m to -4,400 m). The Chilean segment has more unified data distribution for depths of -6,000 m to -7,000 m. This paper presents GMT workflow for the cartographic automatic modelling and mapping deep-sea trench geomorphology.
EN
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.
EN
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.
EN
Evaluating soil strength by geophysical methods using P-waves was undertaken in this study to assess the effects of changed binder ratios on stabilization and compression characteristics. The materials included dredged sediments collected in the seabed of Timrå region, north Sweden. The Portland cement (Basement CEM II/A-V, SS EN 197-1) and ground granulated blast furnace slag (GGBFS) were used as stabilizers. The experiments were performed on behalf of the Svenska Cellulosa Aktiebolaget (SCA) Biorefinery Östrand AB pulp mill. Quantity of binder included 150, 120 and 100 kg. The properties of soil were evaluated after 28, 42, 43, 70, 71 and 85 days of curing using applied geophysical methods of measuring the travel time of primary wave propagation. The P-waves were determined to evaluate the strength of stabilized soils. The results demonstrated variation of P-waves velocity depending on stabilizing agent and curing time in various ratios: Low water/High binder (LW/HB), High water/Low binder (HW/LB) and percentage of agents (CEM II/A-V/GGBFS) as 30%/70%, 50%/50% and 70%/30%. The compression characteristics of soils were assessed using uniaxial compressive strength (UCS). The P-wave velocities were higher for samples stabilized with LW/HB compared to those with HW/LB. The primary wave propagation increased over curing time for all stabilized mixes along with the increased UCS, which proves a tight correlation with the increased strength of soil solidified by the agents. Increased water ratio gives a lower strength by maintained amount of binder and vice versa.
EN
In this paper, the climate and environmental datasets were processed by the scripts of Generic Mapping Tools (GMT) and R to evaluate changes in climate parameters, vegetation patters and land cover types in Burkina Faso. Located in the southern Sahel zone, Burkina Faso experiences one of the most extreme climatic hazards in sub-saharan Africa varying from the extreme floods in Volta River Basin, to desertification and recurrent droughts.. The data include the TerraClimate dataset and satellite images Landsat 8-9 Operational Land Imager (OLI) and Thermal Infrared (TIRS) C2 L1. The dynamics of target climate characteristics of Burkina Faso was visualised for 2013-2022 using remote sensing data. To evaluate the environmental dynamics the TerraClimate data were used for visualizing key climate parameter: extreme temperatures, precipitation, soil moisture, downward surface shortwave radiation, vapour pressure deficit and anomaly. The Palmer Drought Severity Index (PDSI) was modelled over the study area to estimate soil water balance related to the soil moisture conditions as a prerequisites for vegetation growth. The land cover types were mapped using the k-means clustering by R. Two vegetation indices were computed to evaluate the changes in vegetation patterns over recent decade. These included the Normalized Difference Vegetation Index (NDVI) and the Soil-Adjusted Vegetation Index (SAVI) The scripts used for cartographic workflow are presented and discussed. This study contributes to the environmental mapping of Burkina Faso with aim to highlight the links between the climate processes and vegetation dynamics in West Africa.
14
Content available remote Using TeX Markup Language for 3D and 2D Geological Plotting
63%
EN
The paper presents technical application of TeX high-level, descriptive markup language for processing geological dataset from soil laboratory. Geotechnical measurements included equivalent soil cohesion, absolute and absolute deformation index, soil compressibility coefficient by time of immersion depth, exposure time to compressive strength to samples and physical and mechanical properties (humidity, density). Dataset was received from laboratory based experimental tests of the physical and mechanical properties of soils. Data were converted to csv table and processed by LaTeX. Methodology is based on LaTeX packages: {tikz}, {tikz-3dplot}, {tikzpicture}, {pgfplot}, {filecontetns}, {spy} for 3D plotting showing correlation in variables and descriptive statistical analysis based on the data array processing. Results demonstrated LaTeX scripts and graphics: 2D and 3D scatterplots, ternaries, bar charts, boxplots, zooming techniques detailing fragment of the plot, flowchart. Research novelty consists in technical approach of TeX language application for geo- logical data processing and graphical visualization. Engineering graphics by TeX was demonstrated with screenshots of the codes used for plotting.
EN
Current paper presents the results of the experimental analysis on permafrost uppermost soil samples with various physical properties (moisture, porosity) tested with varied external pressure and time. The aim of this work is to test properties of the soil samples intended for the construction of buildings, railways and objects of civil infrastructure by modeled external pressure, data visualization and analysis. Variations in the soil samples were studied by analysis of the equivalent soil cohesion (Ceq) in frozen soil samples. Methods include integrated application of the laboratory experiments, methods of the statistical data analysis and 3D plotting performed by the selected LaTeX packages. Laboratory experiments were performed using KrioLab equipment ‘Sharikovy Stamp PSH-1’. The 15 series of experiments have been tested. Models of the soil strength are graphically presented and statistically analyzed showing the results of the experiment.
EN
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 Geotechnical 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 properties, 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.
PL
Niniejszy artykuł przedstawia eksperymentalne badania dotyczące wymywania metali ciężkich, toksycznych chemikaliów i trwałych zanieczyszczeń organicznych (TZO): WWA, PCB i HCB z pobranej gleby na obszarze przybrzeżnym Västernorrland w północnej Szwecji. Gleba była stabilizowana cementem/żużlem. Próbki poddano zmodyfikowanym próbom wypłukiwania powierzchniowego i wstrząsom z zastosowaniem standardów technicznych Szwedzkiego Instytutu Geotechnicznego (SGI). Eksperymenty przeprowadzono przy użyciu różnych mieszanek środków wiążących (30/70, 50/50, 70/30) i ilości środka wiążącego (120 i 150 kg/m3) w celu przeanalizowania ich wpływu na ługowanie. Opisano właściwości gleby, narzędzia i przebieg pracy. Spoiwa obejmowały cement portlandzki i mielony granulowany żużel wielkopiecowy (GGBFS). Próbki zostały przetestowane w celu określenia min/max zawartości zanieczyszczeń (μg/l) dla metali ciężkich (As, Ba, Pb, Cd, Co, Cu, Cr, Hg, Mn, Mo, Ni, S, V, Zn) i wskaźnika frakcji węglowodorowej w nadmiarze wody. Wymywanie metali ciężkich i TZO oceniano w osadach po dodaniu lepiszcza. Porównania dokonano dla dwóch mieszanek (cement/żużel w 30/70% i spoiwo o wysokiej/niskiej zawartości z niskim/wysokim stosunkiem wody). Wyniki wykazały, że 70% żużel zmniejsza wymywanie metali ciężkich i TZO. Stężenia równowagowe DOC i metali ciężkich przy L/S 10 (μg/l) mierzono podczas eksperymentów z wytrząsaniem w celu porównania ich poziomów w wodzie gruntowej stosowanej jako odciek. Zawartość wyługowaną oszacowano na poziomie L/S 10 w eksperymencie upscalingu (zwiększenia skali) przy użyciu 4 próbek WWA, PCB i różnych frakcji węglowodorów: C10–C40, C10–C12, C12–C16 i C35–C40. Próba wstrząsowa wykazała zmniejszenie wymywania metali ciężkich i substancji TZO z gleby poddanej stabilizacji większą ilością żużla dodawanego jako spoiwo. Najlepszą wydajność wykazała mieszanka spoiwowa zawierająca 30% cementu i 70% GGBFS.
EN
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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tom Vol. 15, no. 4
236--248
EN
The seabed in the ports needs to be regularly cleaned from the marine sediments for safe navigation. Sediments contaminated by tributyltin (TBT) are environmentally harmful and require treatment before recycling. Treatment methods include leaching, stabilisation and solidification to remove toxic chemicals from the sediments and improve their strength for reuse in the construction works. This study evaluated the effects of adding three different binder components (cement, cement kiln dust (CKD) and slag) to treat sediment samples collected in the port of Gothenburg. The goal of this study is to assess the leaching of TBT from the dredged marine sediments contaminated by TBT. The various methods employed for the treatment of sediments include the application of varied ratios of binders. The project has been performed by the Swedish Geotechnical Institute (SGI) on behalf of the Cementa (HeidelbergCement Group) and Cowi Consulting Group, within the framework of the Arendal project. An experiment has been designed to evaluate the effects of adding CKD while reducing cement and slag for sediment treatment. Methods that have been adopted include laboratory processing of samples for leaching using different binder combinations, followed by statistical data processing and graphical plotting. The results of the experiment on leaching of TBT for all samples are tested with a varied ratio of cement, slag, CKD and water. Specimens with added binders 'cement/CKD' have demonstrated higher leaching compared to the ratio 'cement/slag/CKD' and 'cement/slag'. The 'CKD/slag' ratio has presented the best results followed by the ‘cement/slag/CKD’, and can be used as an effective method of s/s treatment of the sediments. The results have shown that the replacement of cement and slag by CKD is effective at TBT leaching for the treatment of toxic marine sediments contaminated by TBT.
EN
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 H WL B (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/cm 3 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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