Design Oosterweel Link with preservation of a historically protected building Samga Silo A-PPT Presentation

PPT Presentation

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The presentation describes the design and construction of the Oosterweel Link tunnel near the historically protected Samga Silo A in Antwerp Harbour. Built in 1895, the 100-by-25-by-32.5-metre masonry building has a shallow foundation and was partly rebuilt after the Second World War. Its age, construction and expansion joints make it vulnerable to ground movement.<br /><br />The project team assessed the silo through a 3D scan, foundation checks, masonry testing and a pile-driving test to evaluate vibration and settlement. They also examined the complex local ground conditions, which include clay, loam, peat and several sand layers.<br /><br />Plaxis modelling was used to compare tunnel-construction options and reduce settlement, including changes to construction phasing, strut arrangements, diaphragm walls, trench support and excavation methods. A structural model developed with KU Leuven was used to estimate crack widths under imposed deformation and identify weak points, particularly below expansion joints.<br /><br />The predicted settlement from all site activities was greatest at the silo’s southeast corner, nearest the tunnel, and was approximately 70 mm. Although substantial settlement and cracking were anticipated, the estimates were based on conservative assumptions. Potential responses included design changes, compensation grouting, and repairs or reinforcement if damage occurred; preventive measures such as compensation grouting were considered expensive.<br /><br />At the time of the presentation, local quay-wall demolition and filling works had been completed, the tunnel diaphragm wall was installed, and excavation had begun. Monitoring showed small but variable settlements, possibly influenced by tides.<br /><br />The project’s key priorities are to limit settlement through design and construction practices, monitor settlement, cracking and vibration, and maintain close follow-up throughout the works, with repairs if necessary.

Keywords

Oosterweel Link

tunnel construction

Antwerp Harbour

Samga Silo A

settlement monitoring

vibration assessment

Plaxis modelling

ground conditions

diaphragm wall

compensation grouting