Design Awards: 2001: Award

The Wellcome Wing, The Science Museum, London

The Welcome Wing, The Science Museum, London

Architect

MacCormac Jamieson Prichard

Structural Engineer

Ove Arup & Partners

Steelwork Contractor

William Hare Ltd

Main Contractor

Kier Build Ltd

Client

National Museum of Science & Industry

In 1995 the Trustees of the Science Museum decided to extend the museum to provide additional exhibition space and a 3D Imax cinema. A design competition was held, which was won by a team comprising: MacCormac Jamieson Prichard, Ove Arup & Partners, and Davis Langdon and Everest. The winning entry offered a building with spectacular internal spaces which occupied a little over half of the available site and left space for a further building on the Queens Gate frontage.

Funding has been provided by the Wellcome Trust and the Heritage Lottery Fund.

The competition concept was for a building supported by two rows of columns, 30m apart, about which were pivoted gerberettes – double cantilevered steel beams, which supported steel floor trusses at their inner ends, and were restrained by tie downs to the ground at their outer ends. The museum’s brief required a 5.5m clear height on the exhibition floors, and this system reduces the effective span of the main trusses from 30m to 25m with a corresponding reduction in depth.

The structure has a basement constructed in watertight reinforced concrete supported on bored piles founded in the london clay.

In the four corners of the building are reinforced concrete stair and lift cores which provide horizontal stability. Between the cores are the main building columns, 110 x 750 reinforced concrete, which carry the marjority of the building load. There are six pairs of columns, 30m apart, on an 8.5m grid in a east/west direction. They sit 5.5m inboard of the facades on the north and south sides of the building. These main columns span vertically from ground floor to roof level, and the roof slab acts as a beam carrying wind loads and stability loads back to the cores.

The gerberettes extend to the north and south faces of the building where they are held by a vertical “tiedown”. The tiedown connects each gerberette on a column down to ground floor level, where the tie force is transferred into reinforcement bars cast into the retaining wall and thence to the foundations. CHS sections are used for the ties, rather than rods, as they are in compression in the temporary condition during erection.

Gerberettes are positioned at the same levels on each column, at a constant dimension below each exhibition floor. The main exhibition trays are supported by 25m long trusses, which span directly between pairs of gerberettes. Gerberettes are pinned to the columns and to the ends of the main trusses, so that this basic framework is statically determinate.

The floors comprise 150mm dense concrete on Holorib decking acting compositely with cellform secondary beams at 2.54m centres. The cellform beams span 8.5m between the main trusses and at the front and rear edges of the floors they cantilever 3m beyond the trusses to enhance the impression of the floors floating in the space. The upper exhibition floors only connect to the rest of the building on their north and south edges. On their west side, they stop 3m short of the west wall. On their east sides they stop 6 to 10m short of the underside of the Imax structure, providing a diagonal slot from the ground floor 32m up to the roof which enables the visitor to see the floors and Imax within the overall internal space of the building.

The regular spacing of the gerberettes which support the exhibition trays is maintained for the Imax gerberettes. However the Imax cinema has a more complex arrangement of floors, with floor trusses required both a various levels and beween main column lines. In order to connect the trusses to the gerberettes, the inner ends of the Imax gerberettes on each grid line are connected together by steel column sections. Load is therefore shared between these gerberettes, and trusses can be supported at any level. This section of the structure is not statically determinate and the effect of the construction sequence on loadsharing between gerberettes had to be investigated.

The floors in the Imax comprise 130mm concrete on Holorib decking generally, except for the base of the auditorium area where it is increased to 200mm thick to provide acoustic separation. The floors are supported by steel beams, at approximately 2.5m centres, spanning between the main trusses.

The roof structure is similar to the exhibition floors, with a concrete slab on Holorib decking acting compositely with cellcore beams spanning between main trusses supported from the inner tips of the gerberettes. The roof is designed for normal loads on top and the same suspended exhibit loads as the floors.

The West Wall fills the 30m wide by 30m high space between the west cores. It is supported by a structural steel frame, which hangs from the tops of the two cores and obtains horizontal support at floor levels from the core walls. It is glazed internally with blue glass, blue light being a theme of the internal space.

The primary structure comprises tubular steel trusses at main floor levels, which span horizontally between, and transmit wind loads to, the cores. The trusses are supported vertically near their ends and at mid point by a system of vertical and diagonal hangers, which take the vertical load to the top of each core at the end connection of the roof level truss. All other trusses have connections to the cores which slide vertically to allow for temperature effects. Connections to the core are also able to slide in the north/south direction, in order to allow the trusses both to act as simply supported, and to avoid stresses generated by changes in temperature. One connection in each truss does not slide in the north/south direction to ensure positional fixity.

The design assumed a specific erection sequence, which was provided in detail to the contractor, who elected to follow it rather than justify an alternative. The side aisles were erected first, and needed temporary bracing in the north/south direction until the roof slab was case and provided the permanent support to the top of the main columns. At this point the north and south aisles formed stable independent structures, and the main trusses and secondary beams were erected from east to west by crawler cranes running on the ground floor slab, which was provided with additional temporary propping to the foundations.

Judges’ Comment

The multi-level space is organised and defined by a masterly combination of structure and light to create a series of wide span unobstructed floors. These provide a superb environment for the enjoyment of the exhibited material.

The Eden Project, Bodelva, Cornwall

The Eden Project, Bodelva, Cornwall

Architect

Nicholas Grimshaw & Partners Ltd

Structural Engineer

Anthony Hunt Associates Ltd

Steelwork Contractor

Biomes – Mero (UK) plc
Link Building – Pring & St Hill Ltd
Visitor Centre –
Snashall Steel Fabrications Co Ltd

Main Contractor

Sir Robert Mc Alpine Ltd /
Alfred Mc Alpine Construction Ltd
Joint Venture

Client

The Eden Project Ltd

The Eden Project, a showcase for global bio-diversity, is one of the most innovative and high profile Millennium Projects. Its network of “biomes”, a sequence of great transparent domes that encapsulate vast humid tropic and warm temperature regions, make it the largest plant enclosure in the world built in the lightest and most ecological way possible.

The Biomes

The design, inspired by the Buckminster Fuller geodesic principle, evolved as a collaborative series of adjustments to a working 3-Dimensional computer model passed digitally between the architects, engineers and contractors. The final structure, the perfect fulfilment of Fuller’s vision of the maximum enclosed volume within the minimal surface area, emerged as a sinuous sequence of eight inter-linked geodesic domes threading around 2.2 hectares of the site: a worked-out Cornish clay pit. These “Bucky balls” (named after Fuller) range in size from 18m to 65m radius in order to accommodate the varying heights of the plant life. Form follows function, a tangible expression of the client’s aim to draw global attention to human dependence upon plants.

The biomes are an exercise in efficiency, both of space and of material. Structurally, each dome is a space frame reliant on two layers. The first, an icosahedral geodesic skin, is made up of hexagonal modules that range in diameter from 5m to 11m. Each comprises six straight, compressive, galvanised steel tubes that are light, relatively small and easily transportable. This makes it possible for each hexagon to be pre-assembled on the ground before it is craned into position and simply bolted to its neighbour by a standard cast steel node.

The primary layer is joined to a secondary one by diagonal Circular Hollow Section members at the node points. Structural stability is guaranteed by the “shell action” of the intersecting domes, that is, meeting of inner and outer structural members to form pinned connections. These are anchored to reinforced concrete strip foundations at the perimeter.

The exact location of the biomes on site has been determined by Solar Modelling, a sophisticated technique that indicates where structures will benefit most from passive solar gain. The architects have capitalised upon this gain by cladding the biomes with ETFE (Ethylene Tetra Fluoro Ethylene) foil.

ETFE represents less than one percent of the dead weight of equivalent glass. It is also strong, anti-static and recyclable, contributing to the overall realisation of the Eden biomes as tangible examples of energy-awareness in action. Elsewhere on the site, energy-awareness is manifest in both the Biome Link building and the Visitors’ Centre.

Biome Link

The Biome Link primarily functions as the entry to the biome complex, and has thus been designed with the ease of visitor movement in mind. It is essentially two structures within one: a front-facing public facility and a two-storey service area to the rear.

The front-of-house element, incorporating a raised steel and timber walkway into the biomes, is of a sloping convex truss system. The trusses consist of curved top and bottom booms with pinned jointed internal strut and tie members. They are supported by raking columns at the front that have expressed pinned joints top and bottom and are stabilised by the building to the rear, a two-storey braced steel-framed structure. The main cellular beams are set out on a radial grid, which can accommodate variations in the span between columns. The secondary beams are at 2.75m centres.

The roof plane is “warped” at both ends, and its profile steel decking supports a green roof system that allows the Biome Link to seemingly melt into the “cool temperature zone” of its surrounding environment. Access is by way of a path that winds down through this zone from the Visitors’ Centre.

Visitors’ Centre

The Visitors’ Centre is primarily an educational facility, with multimedia exhibits serving to introduce the aims and objectives of the project. The structure itself is equally informative. Dramatically curving to complement the contours of the quarry, it consists of two single-storey buildings linked by a partially covered courtyard. While the smaller (service) building nestles into the quarry, the main building thrusts outwards, offering a panoramic view of the biomes.

The main building is steel framed, with the roof beams spanning up to 20m between columns. The beams are set out on a radial grid and slope down at approximately 5° towards the service building at the rear. The roof structure, a steel deck capped with aluminium, forms part of the shallow cone resulting in a radial beam spacing of approximately 5m at the rear of the building and 6m at the front. To the south of the main building, it forms an overhang that shelters a rammed earth elevation. The use of rammed earth walling as a construction technique is local to Cornwall. It is also very much in keeping with The Eden Project’s emphasis on recycling. The material used is the excess from excavation work carried out elsewhere on the site, geologically identified as containing the required range of particle sizes.

The building is stabilised at each end by columns that cantilever from pad foundations. The central section is loaded laterally by the fabric roof, in addition to the wind load. In this section, a truss system in the plane of the roof transfers the lateral loads to braced frames. The truss members are generally sized to limit the deflection of the horizontal truss where it cantilevers at each end.

Judges’ Comment

The size and scale of this complex and visionary engineering project is truly breathtaking. Its success has the hallmark of dedicated and committed teamwork.