New Seismic Isolated Airport Hangar, Istanbul

October 2008

Earthquake Engineering NZ members Beca International Consultants Ltd (Beca) and Robinson Seismic Ltd have provided design and seismic bearings for the seismic isolation of the roof of the new aircraft hangar recently opened at Sabiha Gökçen Airport in Istanbul.

The seismic isolation solution to provide earthquake mitigation for a major airport hangar is a world first.

Robinson Seismic Ltd were approached by their Turkish agent Em-Ke Construction Ltd (Istanbul) to provide a solution for the seismic isolation of the roof of this new hangar, and in turn brought in Beca for their specialist structural engineering and seismic isolation expertise. Beca's Dr David Whittaker joined Em-Ke's Mehmet Özcanli at the opening ceremony.

Typically, structures are isolated at their base (hence base isolation). However, due to the size and complexity of the structure under the hangar floor, that approach did not offer the best solution. Robinson Seismic Ltd and Beca proposed the use of lead rubber bearings installed between the walls and roof of the hangar (seen below in this photo of the hangar under construction are the central bearings). The seismic isolation roof design solution saved US$250,000 in costs as well as providing high earthquake resistance.

The roof is 110 metres x 140 metres and weighs 2,000 tonnes. In total, thirty bearings were used, ten Lead Rubber Bearings for the reinforced concrete central points and twenty (ten each side) Rubber Bearings for the steel outer columns.

Design displacement of the bearings is 300mm. The joints of the spans are also movable in a horizontal direction.

Design of the isolation system for the hangar roof also had to take into account thermal expansion of approximately 50mm and overall wind uplift of up to 1,500 tonnes.  

This MRO (Maintenance Repair and Overhaul) hangar is also the only one in the world to have two basement levels, which contain the servicing workshops.

The following photos show views from the inside of the hangar showing the bearings on top of the columns and from the outside showing the size of the building.

LRBs (Lead Rubber Bearings) installed on central concrete walls.

Airbus A300 in one half of the hangar.

View from the runway side.

For further information:

Alan Wilson, CEO, Robinson Seismic Ltd
A.Wilson@rslnz.com
www.rslnz.com

David Whittaker, Design Engineer, Beca
David.Whittaker@beca.com
www.beca.com