Existing office and warehouse building on the national road, Metamorfosi, Attica, consists of two independent reinforced concrete buildings, separated by an expansion joint, with two basement levels, ground floor and two floors. Characteristic of the building are the relatively large spans (15.00 m.) in the interior, where post tensioned beams were used.
During the Athens earthquake in 1999, severe cracks appeared, as expected in buildings of this type, where large openings and relatively few columns, without shear walls and cores, undergoing severe deformations.
To remedy the problem, the strengthening was externally applied, by adding four antiseismic reinforced concrete cores, two in each building, without affecting the interior. The cores were built in a “U” shape to reinforce the buildings in both directions and, with modern means, were conveniently tied to the existing support structure and founded on the floor of the second basement.
The innovation of the solution lies in the completely external reinforcement of the building. The construction work was completed within two months with absolute efficiency and safety and gave him the antiseismic properties of a new, modern building.