An Eye to the Sky - Inclined grid shell dome of 90 m in Astana, Kazakhstan

A 6500 m² glazed grid shell dome covers the Nazarbayev Centre in Astana, Kazakhstan. Located near the Presidential Palace, this futuristic building, designed by Foster Partners in London, is one of a whole series of prominent architectural buildings in Astana.
The 20° inclined glass roof spans across various levels of the reinforced concrete structure and slopes down to the north. The dome has a span of over 90 m and a rise of about 11 m. A sufficient in-plane stiffness of the rectangular grid of the dome is achieved by the rigidly connected rectangular hollow sections, which are framed by a strong circumferential edge beam. Connections of the grid and edge beam are bolted mainly as a means to cope with the ambitious time schedule that required fast erection during the strong Kazakh winter. By means of a statically determined support, the roof grid and edge beam of the glazed dome remain largely independent of the concrete structure's long-term and deformation behavior. A major issue for the roof structure was the verification of global buckling of the dome. In order to minimize tolerances, all connection surfaces of bolt joints were CNC milled. This article summarizes the design philosophy of the dome steel grid and the relationship between glazed dome and main concrete structure.