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Heathrow Terminal 5: terminals T5A and T5B
Abstract
This paper describes the design and construction of the two terminal buildings in phase 1 of the £4-3 billion Terminal 5 development at London's Heathrow airport A total of 40 000t of steel was used to create 280 000 m2 of space in the dramatic main terminal building, T5A, induding forming a clear span roof of 156 m by 396 m to enclose it In addition to high visibility for passengers, the design provides maximum flexibility for future modifications. In the first of two satellite buildings, T5B, 600 000 m 2 of post-tensioned flat slabs were cast using minimal amounts of formwork and site labour Building these vast structures at the world's busiest international airport also meant all construction operations had to be undertaken within a highly restricted space and with no cranes allowed above roof level.
Engineering and architecture are close disciplines with much overlap. Co-operation between design team partners to combine their experience leads to successful building structures. The paper discusses the key issues in the design of shells, giving methods of categorisation to aid communication within the design team. There has been a recent move towards freeform shells and the paper shows the necessity of working these up from clear rational parameters rather than relying on a computer-generated image alone. It shows the key material parameters that need to be addressed in grid shell design and shows how results from model tests and smaller-scale precedents can inform choice of material and size of structural elements. A review of recent shell structures includes references to timber gridshells (Downland, Savill) comparing their form-finding, modelling and construction techniques with the Pods, Scunthorpe (construction start September 2009)
This paper describes the design and construction of the vast piled basement structures for the three terminal buildings at London Heathrow's £43 billion Terminal 5 project together with 1 million m2 of associated aircraft pavements. The basements are up to 2.0 m deep and involved the excavation and reuse of 6-5 million m3 of gravel and clay. The aircraft pavement involved a number of innovations including development of a new high-strength concrete, which delivered a thinner construction and resulted in programme and environmental benefits.
This paper covers the evolution of the structural form and build sequence; the innovative node design; the analysis of tolerances and fit-up; the fabrication and castings; the temporary works and strand jacking; the behaviour during prestressing and load transfer and demonstrates how good design, construction and teamwork can bring additional value to our clients.
This paper describes the design and construction of the vast piled basement structures for the three terminal buildings at London Heathrow's £43 billion Terminal 5 project together with 1 million m2 of associated aircraft pavements. The basements are up to 2.0 m deep and involved the excavation and reuse of 6-5 million m3 of gravel and clay. The aircraft pavement involved a number of innovations including development of a new high-strength concrete, which delivered a thinner construction and resulted in programme and environmental benefits.
The abutment structures provide the support for the main span of the dramatic 176 m free-spanning roof of Heathrow's Terminal 5 ( T5) main terminal building. The abutments contain many complex engineered components, which are replicated 22 times throughout the roof structure. The roof modules were essentially made up of the central portion of the span containing the majority of the roof cladding supported by a 107 m bow-string arch structure, which was in turn supported by the end abutments which form the subject of this paper. The programme for the construction of T5 was time-critical and relied heavily upon constructing the roof in a series of modules to an extremely ambitious cycle time. The construction of the abutments was key to achieving these rapid cycle times. In order to ensure that the cycle times could be achieved, BAA embarked upon what was termed the abutment first run study ( AFRS) essentially to determine, ahead of the construction on site and offline from the critical path, that these crucially important cycle times could be achieved. The current paper describes the rationale behind the study and the preparations made for the construction of the AFRS at Severfield Rowen's facility in North Yorkshire. The paper focuses on how practical refinement of complex installations can contribute to savings of both time and cost and how attention to detail during the design and manufacturing phases ensured that the components successfully fitted together. The effectiveness of the AFRS helped to guarantee that when the roof module was suspended from the strand jacks some 30 m in the air, the support points on the abutment structure were correctly aligned.