Geoff Werran, project director, and Fergus McCormick, structural engineering leader, of Buro Happold describe the concrete works at the new Aviva (Lansdowne Road) Stadium in Dublin.
The Aviva Stadium (previously Lansdowne Road) has a long and proud sporting history. The oldest international rugby ground in the world, it had seen many developments since its beginnings, but it was recognized for some time that it no longer provided the requirements of an international sporting arena. Lansdowne Road Stadium Development Company, a joint venture between the IRFU and the FAI, was established to redevelop the stadium into a world class sporting facility.
The chosen design for the redevelopment is the work of multi-national engineering consultants Buro Happold and international architects, HOK Sports, working with Scott Tallon Walker.
The new Aviva Stadium is the first truly site responsive stadium of its kind in the world. Its form, mass, materials and aspect are defined by the site and its surrounds. The proposed stadium consists of a continuous curvilinear shaped stand enclosing all four sides of the ground. The south, east and west stands all have four tiers of seating with the majority of the spectators in the desirable side locations of the pitch. On the north side there is only one tier, as the stadium comes down dramatically in height to minimize the impact of the building on the adjoining neighbourhoods.
The design is a state-of-the-art modern stadium, which will have an all seated capacity of 50,000. All seating will covered by the roof.
Site works on the stadium are substantially complete and work on the roof structure and glazing has recently commenced. Buro Happold delivered a full structural engineering service to the project including full reinforcement detailing and scheduling, and the rest of this article describes the uses of concrete within the project.
The form of the stadium quickly evolved to the curved one whose shape is already seen on site. This form placed floor areas and concourse widths in accordance with functional performance. In detailed design, working using parametric software, the buildings sections and plan were optimized. An additional key feature in developing the sleek design with a moderate overall height for economy was slim floor-to-floor dimensions.
It was clear to us as designers that the fluid geometries and shallow storeys were best suited to being mostly constructed with a concrete frame.
The suspended floors are generally in-situ flat slabs spanning generally up to around 8m to 10m, but with variable cantilevers at the building edges of up to 4m. Pre-stressed concrete floor solutions are always considered, and as a practice, we have extensive experience of their design and construction, but complexities of stadium mean they are difficult to deliver easily and economically in Europe.
Columns are in situ and range in shape from circular, square, rectangular to the feature blade columns at the edge of the building, whose geometry and elevation, illustrate and help display the dramatic form of the building.
The seating tiers are generally formed of conventional precast concrete units, but for large areas of the lower tier, an insitu solution was developed with a slimmer overall depth to enable better space usage below the tier whilst maintaining ground floor construction above the high water table.
Precast seating tier units at lower tier, premium tier and box level are supported by concrete rakers. As with the lower tier, detailed considerations resulted in Buro Happold delivering both precast and in situ concrete solutions. After the appointment of the main contractor, John Sisk, collaborative workshops between the design and construction team explored and evaluated the solutions in the light of specialist sub-contractor preference. The design solution remained with the exception of some premium rakers which were revised from in-situ to precast to help trim time from the programme.
In addition to the major frame of the stadium, the project has included a double storey concrete basement for plant and attenuation constructed below the water table.
Specification of the finishes by Buro Happold followed a detailed study of the function and visibility of every wall, column, floor and beam surface. At tender, all surfaces were defined as being formed or unformed, visible or non-visible, requiring patterned formwork or not. The finish type for unformed surfaces was defined according to whether a further architectural finish would be used and the requirement for the form type: steel, ply or GRP was specified. Outline requirements for the board patterning were set-out and drawn.
Post-contract, the design team and construction team worked closely to ensure the project requirements were understood by each party before the contractor proposed form layouts for all of the works. These were reviewed by the design team, in a proactive and positive practical relationship with the contractor. These processes have helped deliver finished concrete patterning arrangements of excellent control and quality.
For balanced reasonable economic design, stadia inherently involve extensive unfinished surfaces. The project team on the Aviva Stadium have embraced the philosophy of delivering maximum appearance and quality to the exposed concrete face of the building, using all the subtleties and tools available along with the talents and experience of the personnel involved.
Significant site works engineered by Buro Happold have included the demolition of the former stadium West stand over the DART and the creation of a new rail corridor integrated within the overall development next to the stadium. This was constructed over a series of highly programmed Bank Holiday rail possessions, with a precast solution designed by Buro Happold to enable rapid installation.
At the North of the site, Buro Happold proposed a realignment, new structure and site sequence methodology for the Swan Culvert. This was agreed with Dublin Council as a required and necessary improvement. The new sewer portions are formed of pre-cast segments.
The application of knowledge and experience of Buro Happold’s stadia expertise helped create the design for this complex project. A key part of this has been exploiting the potential and full variety of techniques of concrete design, detailing and construction. Since award, the construction is on programme. This is a tribute to many things: the skills of the design team; the energies and talents of the construction team, which embraced the philosophies of the solution and aspirations of the client for a world-class building; and an understanding client and project management team who have linked the various elements together – with great teamwork between all three.