Roofing & structural technology for stadiums.
Stadiums are usually of three configurations, oval, open, and horseshoe respectively. Even rectangular-shaped stadiums exist but they aren't that common as the others. Here we shall look deeper into the structural systems of a stadium's roof.
A stadium's roof is a critical part of the design and structure, it has a major effect on the construction cost, time, and the spectator's interest. For the recognition and unique design of the architect's plan, roof structure holds a vital element in the project. Throughout the history of stadiums, structural forms and roofing patterns have been involved, designers and engineers still work on creating the epic and new.
In this blog, we shall discuss some of the most prevalent roof structures of a stadium.
1. Post and beam structure
It is one of the most simple structural systems and it consists of two elements, columns, and beams. Compared to other structural systems. Post and beam are cheaper and easier to construct. Here columns are arranged as grid patterns and larger beams called girders to connect the columns.
Using of post and beam structure limits the pattern to a specific geometric system and obstructs the view of the spectators at some plots.
2. Goal post structure
This structural system is very much similar to the post and beam structure except for the reason that it has columns only at the perimeter. This also means that each section of the roof is supported by a larger single girder, here the girders are much longer and deeper. Stadiums with goal and post structure are limited to rectangular geometry and require regular inspection for safety reasons.
3. Concrete shell structure
With the advancement in engineering, the strength of concrete has been increased incredibly and is used to create concrete shells that are thin structures that curve in one or two directions. The strength of these shell structures is dependent on their geometric shape and thickness of the material. The principle of strength through curvature is to be applied to thin sheets of reinforced concrete here and has been efficiently used to build stadium roofs. Construction costs and time was taken are usually higher for this structure and pre-cast concrete is preferred for this type of structural system.
4. Cantilever Structure
This is the type of structural system in which roof structures are supported at the exterior end and hang freely over the stands. Unobstructed view counts for the major benefit of using Cantilever structure for a stadium's roofing and also they are not restricted to rectangular geometry. Due to the dramatic look, it is capable of showcasing, architects often encompass them as a highlight in their design. Costing and wind direction are two notable disadvantages of using cantilever structures for roofing.
5. Air-supported roofs
In air-supported roofs, the structural integrity of the roof structure comes from the internal pressurized air permitting these roofs to span great distances, as long as a constant air supply is provided. Throughout history, many stadiums have used air-supported roofs. Even though they have low capital costs, they are susceptible to damage and have a short design life span.
6. Cable-net structure
Cable net structures consist of two parts: the structural three-dimensional steel net made of steel cables and the fabric covering. Advanced mathematical analysis and form-finding techniques are often used to determine the optimal positioning of the steel cables so that the structure is in complete tension.
7. Membrane structure
The roof covering of the membrane structure provides both structure and enclosure. This system provides the opportunity to design a beautiful form with large uncluttered spans thus creating exceptional lighting characteristics often not achievable with conventional materials and systems. Major benefits count for the application of any geometry into the design and provide a more airy and open pattern.
8. Compression- Tension ring
This structure is feasible only for a circular or elliptical system. Here, the roofing system consists of a compression ring around the exterior and a tension ring on the inside, creating a doughnut shape. These two rings are connected by the radial members that carry the roof covering. Roofs using this structural system can span large depths with ease. Modern-day stadiums have modified this structure to create great designs by adding extra fabrics to it.
9. Combining systems
As the designers become more inventive and demands start increasing to create an epic structural design, architects often tend to combine all these systems to produce the magnificent.
The above mentioned are the prominent design structures in use for the stadium's roofing. As decades pass by, industry expands and inventions rise up which paves way for the evolution of the next structure.