Designed by Foster and Partners, this is a signature mixed-use tower and podium project with 100,000 m2 commercial, residential, retail and hospitality spaces in Istanbul. A-teknik coordinated between the international (Thornton Tomasetti) and the local team of engineers (Balkar) to provide structural peer review services for this reinforced concrete tower of 60 stories.
Designed to the state-of-the-art performance-based seismic criteria of tall buildings, the building is very slender with a 30m by 80m floor plan at the base, tapering to 60m on the long side at the top. The structure is composed of two concrete cores which are 1.4m thick at the base and special concrete moment frames with inclined perimeter columns.
Against the time-dependent vertical creep and shrinkage of concrete occurring in a relative fashion between the cores and the perimeter, a staged construction analysis was also performed to determine the shortening of building during construction.