The building is located in an earthquake zone, the horizontal seismic forces being much greater than the wind forces. To cope with them, the structure is provided with diagonal bracings, left externally exposed as characteristic features of the elevational treatment. In front of each façade there are lattice panels comprising continuous columns and two sets of diagonal members. This lattice system stiffens the building against lateral deflection. Additional stiffening of the building is provided by rigid frames in the central core which can resist 25% of the seismic forces. The external lattice system consists of welded box-sections with plate thicknesses up to 100 mm. The diagonals are 410 x 410 mm in cross-section, being arranged at a distance of 350 mm from the facade. The columns, which are 960 x 510 mm in cross-section, are incorporated into the facade. Each corner column is actually a pair of columns, connected at right angles to one another.
Floor loads are supported in the interior by the core walls and at the periphery of the building by the external columns and by hangers. The latter are connected, at every sixth floor, to the intersection points of the diagonal elevation of the building. Floor edge beams positioned just behind the facade are connected to the columns and hangers by means of brackets. The floors span without intermediate columns between these edge beams and the walls of the core. Each floor comprises main and secondary beams and a 6.5 cm thick in-situ concrete slab on steel trough decking.
Curtain wall with mullions and transoms of aluminium sections are attached to the edges of the floor. Mullions are spaced at 1.57 m centres, while transoms are at 1.98 m. Infilling consists of double glazing.
Notes:
cope (with) v. зд. противодействовать
elevational treatment отделка фасада
seismic forces сейсмические силы/воздействия