The demolition and construction of the multi-level basement was a key challenge for this project. The basement construction was located directly adjacent to Edinburgh One. This required the use of a contiguous piled wall located, constructed at the interface, to provide lateral support to the excavation of the basement and the installation of the North Core Foundations.
The excavation of the basement was achieved with king post walls on three boundaries. The King Post walls were propped at mid height by flying shores spanning the width of the basement to enable the construction of the foundations, ground slab and the first suspended slab. The temporary flying shores were removed once the suspended slab linked the North and South Cores.
The perimeter concrete walls and ground slab of the basement are constructed with a waterproofing additive, Pudlo, to limit the time required for external tanking allowing the contractor to cast the single sided walls against the temporary king post wall.
Site access was constrained on all sides and construction requires careful coordination and consideration for access and the adjacent land owners and users.