| 2. |
- Petrich, Christian, et al.
(författare)
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Time-dependent spatial distribution of thermal stresses in the ice cover of a small reservoir
- 2015
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Ingår i: Cold Regions Science and Technology. - : Elsevier BV. - 0165-232X .- 1872-7441. ; 120, s. 35-44
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Tidskriftsartikel (refereegranskat)abstract
- Static ice loads (ice actions) are a key design parameter for dams in cold climates. However, their theoretical description is still elusive, introducing uncertainty in design and hindering development of remediation measures. We present and analyze measurements of stresses due to thermal loads in a small reservoir in northern Norway. Several weeks of observations, including both cold and warm spells, were well-described by a simple equation that accounts for thermal expansion and temperature-dependent creep. One model parameter was found to depend systematically on the location of measurements within the reservoir. Biaxial stress measurements showed that the stress field was not homogeneous. Results suggest that the stress field in reservoirs should be predictable from first principles with numerical methods and point toward a promising, simple parameterization.
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| 3. |
- Sand, Björnar, et al.
(författare)
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Three years of measurements of first year ridges in the Barents Sea and fram strait
- 2015
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Ingår i: Proceedings of the 23nd International Conference on Port and Ocean Engineering under Arctic Conditions.
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Konferensbidrag (refereegranskat)abstract
- During three expeditions in March 2011, March 2012 and April/May 2013 with the Norwegian coastguard vessel "KV Svalbard", two pressure ridges around Svalbard, one ridge in Fram Strait and three ridges in Olga strait have been studied with respect to ridge geometry and physical and mechanical properties. With a discrete measurement, which is of most interest here, information can be obtained on the overall size and shape of an individual ridge at one particular location, both above and below the waterline. This approach provides detailed quantitative information on both the sail and keel size and shape, of a specific ridge, as well as its porosity. It does not supply any information on ridge spacing. The results of individual profile measurements are discussed. Measurements of vertical profiles along the spine and transects perpendicular to the spine are presented for these ridges. The sail height, sail width, keel depth and keel width, consolidated layer thickness, rubble block sizes and porosities are examined for each ridge. The results presented in this paper contribute to more data in terms of geometry and morphology of the first-year ridge off Svalbard, in Fram Strait and Barents Sea. Compression and tensile strength properties are important input data for constitutive modelling. Still strength properties of ridged ice are not yet sufficiently investigated. Uniaxial compressive tests were performed with horizontal and vertical loading directions and the results from the testing of level ice and consolidated layer are summarized with consideration of total porosity.
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