Abstract | As part of a planned development for Billy Bishop Toronto City Airport, new land reclamation and related marine works are required to extend both ends of the main runway into Lake Ontario. Wave conditions at the eastern end of the runway are relatively mild, as the site is sheltered inside Toronto Harbour. However, an extension at the western end of the runway will be directly exposed to strong winds, energetic wave conditions, high water levels, and winter ice conditions. An engineered revetment is required to prevent erosion, preserve stability, and protect the exposed western reclamation from attack by waves and ice. The design challenge was compounded by the requirement to minimize the frequency and extent of wave run-up and overtopping during storms as much as possible in order to avoid frequent inundation of the runway. At the same time, the crest elevation of the perimeter revetment was limited by the elevation of the existing runway and various other requirements for safe operations at the airport. A large-scale 3D physical modelling study was undertaken which played a crucial role in developing, testing, and optimizing the design of the perimeter revetment and for costing the marine works. In order to accommodate the stringent design requirements, several innovative revetment design concepts (featuring lower crest elevations, milder slopes, thicker filter layers, and thicker armour layers than normally seen in conventional designs) were tested in a wide range of harsh wave, wind, and water level conditions. |
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