Norwegian Geotechnical Institute (NGI) Digital Archive
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A simple continuum approach to predict the drained pull-out response of piles for offshore wind turbines
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Evolution of the Exmouth-Barrow carbonate margin through the Miocene: Insights from 3D seismic data and field investigations (North West Shelf, Australia)
Get PDFCarbonate margins are records of the palaeoclimatology, palaeoceanography and palaeogeography of continental shelves, and their study can help identify both regional and global palaeoenvironmental changes. This study documents the evolution of the Exmouth-Barrow margin, which records one of the largest ramp to rimmed platform transition documented yet, throughout the Miocene. The research is based on the integration of onshore outcrops, offshore wells and 3D seismic data. The margin evolution can be divided in four main phases, including: (1) progradation of carbonate clinoforms, forming a depositional ramp, during the early Miocene; (2) sabkha development and extensive dolomitization, concomitant with the Miocene Climatic Optimum; (3) formation of a carbonate barrier-lagoon system associated with slope channels during the middle Miocene; and (4) onset of a dominantly siliciclastic sedimentation from the end of middle Miocene onward. Overall, this study illustrates how outcrops and offshore seismic data can be integrated to reconstruct the regional stratigraphic and palaeoenvironmental evolution of a continental margin, with outcrops providing precise but local information, while 3D seismic data allow the basin-scale reconstruction of the palaeolandscape.Evolution of the Exmouth-Barrow carbonate margin through the Miocene: Insights from 3D seismic data and field investigations (North West Shelf, Australia)publishedVersio
Distribution of PAHs, PCBs, and PCDD/Fs in products from full-scale relevant pyrolysis of diverse contaminated organic waste
Get PDFBiomass pyrolysis is the anoxic thermal conversion of biomass into a carbon rich, porous solid, often called biochar. This could be a better waste management alternative for contaminated organic wastes than incineration, due to the useful properties of biochar and potential for carbon sequestration. There are, however, concerns about the potential formation/destruction of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs). Six organic wastes, including digested sewage sludges, wood wastes, and food waste reject, were pyrolyzed (500–800°C) in a full-scale relevant unit (1–5 kg biochar hr−1). Removal efficiencies for PCBs and PCDD/Fs were > 99% in the produced biochars. Biochar PAH-content (2.7–118 mgkg−1) was not significantly correlated to feedstock or temperature. PAHs (2563–8285 mgkg−1), PCBs (22–113 µgkg−1), and PCDD/Fs (1.8–50 ngTEQ kg−1) accumulated in the pyrolysis condensate, making this a hazardous waste best handled as a fuel for high temperature combustion. Emission concentrations for PAHs (0.22–421 µgNm−3) and PCDD/Fs (≤2.7 pgTEQ Nm−3) were mainly associated with particles and were below the European Union’s waste incineration thresholds. Emission factors ranged from 0.0002 to 78 mg tonne−1 biochar for PAHs and 0.002–0.45 µgTEQ tonne−1 biochar for PCDD/Fs. PCDD/F-formation was negligible during high temperature (≥500 °C) biomass pyrolysis (69–90% net loss)Distribution of PAHs, PCBs, and PCDD/Fs in products from full-scale relevant pyrolysis of diverse contaminated organic wastepublishedVersio
Effect-Directed Analysis Based on Transthyretin Binding Activity of Per- and Polyfluoroalkyl Substances in a Contaminated Sediment Extract
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Impact of hyper-elasticity on cyclic sand modelling: A numerical study based on SANISAND-MS
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Snowmelt contribution to Arctic first-year ice ridge mass balance and rapid consolidation during summer melt
Get PDFSea ice ridges are one of the most under-sampled and poorly understood components of the Arctic sea ice system. Yet, ridges play a crucial role in the sea ice mass balance and have been identified as ecological hotspots for ice-associated flora and fauna in the Arctic. To better understand the mass balance of sea ice ridges, we drilled and sampled two different first-year ice (FYI) ridges in June–July 2020 during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC). Ice cores were cut into 5 cm sections, melted, then analyzed for salinity and oxygen (d18O) isotope composition. Combined with isotope data of snow samples,we used a mixing model to quantify the contribution of snow to the consolidated sea ice ridge mass. Our results demonstrate that snow meltwater is important for summer consolidation and overall ice mass balance of FYI ridges during the melt season, representing 6%–11% of total ridged ice mass or an ice thickness equivalent of 0.37–0.53 m.These findings demonstrate that snowmelt contributes to consolidation of FYI ridges and is a mechanism resulting in a relative increase of sea ice volume in summer. This mechanism can also affect the mechanical strength and survivability of ridges, but also contribute to reduction of the habitable space and light levels within FYI ridges. We proposed a combination of two pathways for the transport of snow meltwater and incorporation into ridge keels: percolation downward through the ridge and/or lateral transport from the under-ice meltwater layer. Whether only one pathway or a combination of both pathways is most likely remains unclear based on our observations, warranting further research on ridge morphologypublishedVersio
Life cycle analysis (LCA) and costs for energy storage in piles
Get PDFThis report is a part of the research project Sustainable energy from soils (BEAR). The BEAR project is a collaboration project between the industry, municipality and research institutions in mid Norway, funded by the regional research fund of Trøndelag (grant number 32116). The BEAR project involves designing and testing an energy concept that utilize the soil as a stable source of thermal energy for buildings, meanwhile also working as an integrated part of the building foundation, so called “energy piles”. The hypothesis is that integrating heat exchangers within the building foundations will enable and reduce the investment cost for the establishment of ground source heating systems in buildings that are situated on soils. The BEAR consortium consists of Malvik Municipality (project owner), NGI (project lead), Winns AS, Fundamentering AS, Noranergy AS and NTNU. BEAR comprises of four working packages, where this report summarizes the results and findings of work package 3 (WP3 - Evaluation)
Different mechanisms of Arctic first-year sea-ice ridge consolidation observed during the MOSAiC expedition
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Use of numerical modelling when designing a full-scale field test of landfill top covers
Get PDFLandfill closures typically include cover systems with a low-permeable barrier to limit the flow of water to and from the waste to minimize contamination of the surrounding environment. Commonly the lowpermeable barrier in the top cover consists of compacted clays and/or geomembranes. An ongoing fullscale pilot test in southern Norway examines the performance of landfill low-permeable barriers, sometimes called sealing layers, constructed of two different recycled clayey soils compared to a traditionally used dry crust clay. Four test cells have been constructed with a top cover consisting of a coarse protection layer overlying a sealing layer. A lysimeter lies at the base to collect and measure the water which percolates through the entire top cover. By modelling the seepage through a simplification of the pilot test top cover, this paper investigates how 2D numerical hydrogeological modelling may be used to inform the design and/or construction of top cover pilot tests in temperate climates. It assesses the effect of sealing layer inclination, thickness and saturated hydraulic conductivity, as well as how detailed, as-built cross-section models compare to simple column models. Saturated hydraulic conductivity was found to be the most important feature when varied within a realistic range. Further, it asserts that 2D modelling may provide an efficient way to assess the consequences of deviations from designed geometry. Simple column models were found to be as suitable for this as more detailed crosssection models.Use of numerical modelling when designing a full-scale field test of landfill top coverspublishedVersio