Single-span roof: flexible solution and unifying element
Travelling through the main terminal building, you get an intuitive feel for where you are within the terminal. Stretching 156m in a single span, the roof that provides this unifying element is a product of working in a collocated, integrated team, one of the many successful elements with which Arup was involved at T5.
To create a flexible space, the three-storey superstructure of the main Terminal 5 building, T5A, is entirely separate from the roof and the façades. The integrated project team adopted a ‘design for manufacture and assembly’ approach to the T5A roof design in order to reduce construction time, risks, and cost and worked with steel manufacturers and sub-contractors as part of a team. As a result, the T5A roof and façade were completed on budget, three months ahead of schedule.
An advanced computer model of how the roof would behave in windy conditions enabled the team to save 800 tonnes of steel in designing the structure. Steel connections were then designed to be manufactured to a normal level of tolerance and adjusted after they were in place. Finally, the roof was assembled on the ground and then jacked into place, since the airport’s radar system prevented the use of tall cranes.
The design team made use of the single model environment created for Terminal 5 to analyse in 3D how the roof would perform. Investing in careful planning helped to reduce risks and cut costs.