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The snow galleries along the Iron Ore railway line in northern Sweden have faced problems in recent years due to increasingly large snow loads, and several galleries have been damaged. These incidents motivated an evaluation of the maximum load supported by the galleries before collapse, which is presented in this study. In 2021, a monitoring system was installed in one of the main frames of two snow galleries built in the 1950s to follow up with temperature and displacements, including a trigger that sends out a warning message when a critical load is reached. A literature review on snow loads was performed, followed by calculations on snow distribution on the galleries based on the Eurocodes and National Swedish Standards. Finite element 2D and 3D models were created using AxisVM to accurately assess the efforts in the structural elements. Analysis and discussion are complemented by observations from site visits. It was concluded that the critical loads supported by the galleries are lower than the requirements of today's standards, but since secondary construction elements were damaged before the main frames reached their full capacity, no major collapse has yet taken place. The cobweb effect (load re-distribution between the neighboring elements in a 3D structure) influenced the behavior of the galleries in the 3D analysis and the capacity of the main frames proved to be significantly increased compared to the 2D assessment. [ABSTRACT FROM AUTHOR]

A new bridge was built in Kalix, northern Sweden, to replace an existing prestressed concrete box‐girder bridge that had been in service for over 60 years. The old bridge had a total length of 283.6 m divided into five spans: 43.9 m, 47.0 m, 94.0 m, 47.0 m, and 43.9 m. It was constructed using the balanced cantilever method with segments having lengths of around 3.0 m. The need for replacement arose from recommendations extracted from an assessment of the old bridge's state and capacity. In addition to the construction of the new bridge, its replacement necessitated the creation and evaluation of demolition procedure for the existing bridge. This procedure had to be carefully designed to avoid damaging the new bridge and stability‐related issues but also to prevent debris from falling into the Kalix River, which is part of a Natura 2000 protected area. This paper discusses various issues considered while developing the demolition strategy, including the use of bed‐rock anchored tendons, intermediate support fixing at specific locations, and proper evaluation of position of the demolition equipment supported by the bridge, among others. The problem of disposing of the demolished material is also discussed. [ABSTRACT FROM AUTHOR]

The Iron Ore Line is a railway in northern Sweden and Norway, crucial for iron ore transportation. Snow galleries safeguard this route, ensuring uninterrupted traffic for efficient operations. A snow gallery is a protective structure that shields roads and railways from heavy snowfall and avalanches. Reported damages to these structures caused by excessive snow loads have prompted an investigation to prevent further issues. This paper presents an analysis of the evolution of snow load calculations over time, though a comparison of Swedish design standards. The design snow loads required by current standards have increased up to 60% from the initial regulations, depending on the location of the structure. Besides, climate change is predicted to further increase snow loads due to more frequent winter precipitation, higher snow density, and extreme snowfall events. This analysis is part of a broader research project involving numerical simulations, live monitoring, and a digital twin monitoring system of some snow galleries in the Iron Ore Line. [ABSTRACT FROM AUTHOR]

Traditional visual inspections of existing infrastructure have limitations such as safety risks, limited accuracy for subsurface defects, and subjective assessments. Modern inspection techniques like terrestrial laser scanning, closerange photogrammetry (CRP), and infrared scanning offer faster and more accurate data collection, allowing for more informative and precise descriptions of objects, while minimizing traffic disturbances often associated with visual inspections. In this paper, CPR, a non‐destructive survey technique for reconstructing 3D shapes from 2D images, is used for the inspection of five bridges in Northern Sweden. The surveys were performed under different weather conditions, using different data acquisition equipment and personnel with different levels of experience. The acquired images were used to create 3D models of the bridges and to evaluate the evolution of damages over time. Results showed that although better models were created when using equipment with higher specifications, cheap gear such as GoPro or cellphones can also be used for the cases in which a lower level of detail is required. Furthermore, initial experience of the personnel does not seem to have high influence on the results. [ABSTRACT FROM AUTHOR]