The Onassis House of Letters and Arts, Greece: A Design Overview

The Onassis House of Letters and Arts is a reinforced concrete (R/C) structure having a unique shape and dynamic behaviour. The main feature of the building is an egg-shaped shell structure, hosting a large auditorium, with slender columns along its perimeter. In order for the structural design to meet the high performance seismic specifications that were set, seismic isolation was deemed necessary. Friction pendulum (FPS) type isolators were selected and placed under the ground floor slab, for reasons of reduced cost and construction effectiveness. Dynamic response spectrum analyses as well as non-linear time history analyses using selected earthquake records were performed on a three-dimensional (3D) model of the structure shedding light on the seismic behaviour of the building. However, applying seismic isolation results in problems regarding the significant concentrated compressive forces from the isolators and in construction difficulties such as the potential replacement of isolators and the design of construction joints that ensure the free movement of the building despite the existence of ramps, elevators and staircases that pass through the level of seismic isolation. In addition, special care was needed for the design of the ground floor slab and the egg-shaped shell structure housing the auditorium.