Computational techniques are used in the design and construction of modern stadiums has increased significantly. It is not true to say that modern stadiums cannot be designed or constructed without the use of such computation techniques, but it is true to say that modern stadiums would not be completed within the project timescales without the use of computerised techniques. However, a computer is only a tool to be used by competent designers and engineers to enhance the process of design and construction. This blogs looks at some of the significant computational techniques currently available for use in the design and construction of stadiums.
One of the most powerful computational techniques to make an impact on the design of stadiums is parametric design. Instead of representing a design as a series of fixed quantities, parametric design represents the design as series of relationships. These relationships can relate to non-geometrical characteristics, such as cost or time, but a good stadium-specific example also involves the geometry of a seating bowl formed from precast concrete terrace units.
The going and rising are primary dimensions defined by the architect, and are related to the requirements for sightlines. There are many more dimensions to fully define the geometry of the precast unit. Some of these dimensions will only be finalised when the supplier of the terrace units is appointed. The precast units can be visualised as either a:
series of unique objects with individual dimensions – a stadium seating bowl could contain many thousands of such objects. families of components, where the dimensions are represented by parameters – the values of the parameters are dependent on the location of the precast unit.
Therefore, all the terrace units can be represented with relatively few parametric components. The use of parametric components is an important technique, but it starts to deliver real benefits when aligned with associative design. Associative or constraint modelling occurs when the relationships and interactions between several components are specifically defined. In the example of a stadium seating bowl, each precast terrace unit can be represented as a parametric component, however the sightlines of the bowl can only be calculated when all the parametric terrace units are linked together. In fact it is the requirement for the sightline that will ultimately define the values of the unique dimensions for each precast terrace unit.
The use of parametric components with associate modelling is extremely powerful in allowing multiple scenarios to be tested rapidly. In practical terms there are usually several conflicting requirements by different stakeholders over the same components. For example, the parabolic curve that defines the optimum bowl geometry is conflicted with minimising the number of unique precast units, which in turn has a cost impact.
Using parametric and associative modelling techniques it is possible to test the effect of standardising units while meeting requirements for sightlines. The picture below shows a parametric workflow detailing how sightlines in section are linked to objects in a building information modelling (BIM) model. This exercise and the use of parametric design assisted the design team in creating an efficient seating bowl that brings everyone in the stadium as close to the action as possible.
The large size of stadiums means that even subtle changes in the geometry of the profile can have significant impact on the overall size of the stadium, which in turn can affect the area of roof, floor slabs and external cladding. On large stadiums, an increase in the radius of the stadium by 1 m can add roughly 1000 m2 to the roof area. In stadium design the geometry of all components flows from the geometry of the bowl. A lot of progress has been made in the parametric design of seating bowls, and most specialist sports architects will now use some form of parametric bowl design software. Future challenges will lie in extending parametric design beyond the bowl, into the frame and beyond.
Internal environmental simulations
Major international sporting events such as the FIFA World Cup or Olympic Games are held across all continents and in a wide range of climates. It is necessary for venues hosting sporting events at the highest level to ensure the appropriate environment for spectators and competitors. In order to ensure, and in some cases justify, the decision to host such sporting events requires considerable technical simulation relating to the internal environment of the stadium. Bowl cooling is gaining popularity as a method of ensuring that a country’s natural climate is not a barrier to sport. The following are the key drivers for bowl-cooling design:
- supply air-temperature variation based on time of day/year.
- control of delivery for venue flexibility and energy saving.
- effective ventilation strategy for comfort, energy, and delivery.
- plant space limits are determined by the stadium envelope, sightlines and the need to maximise seats while minimising volume of stadium.
- minimise capital expenditure and operational expenditure.
Recent experience has shown that the most efficient method of providing spectator comfort in hot humid climates is to provide a ‘cool zone’ or microclimate within the spectator zone, rather than to cool the entire volume of the stadium. This is done by providing cooled air directly to the spectators through vents within the seating bowl attached to a cool air supply through ducts or plenums behind the seating bowl.