J. Appleton, J. Almeida, T. Abecassis, Portugal
The two twin towers have five underground floors and 25 upper floors. The structure of the elevated floors is a composite steel girder/concrete floor system. The resistance to the loads due to horizontal winds and to seismic actions is performed by two concrete shear wall cores that surround the lifts and stairs. At 11 m above ground level a prestressed grid supports the loads of the elevated floors and spans only between the shear wall cores. The foundations of the central core are prestressed concrete slabs of variable thickness from 1,30 m to 2,50 m. The design particularly focussed on the construction process and on the wind and earthquake response.
