Pub. 5 2015 Issue 2

15 MINING FOCUS expectations about what the stadium has to provide. Any building on such a large scale needs a frame that is built of steel or reinforced concrete. In addition to the playing field, sta - diums also need conference rooms, locker rooms, galleries, gyms, press services for television and radio, tiers, roofs, staircases, tracks, and so on. All of the stadium’s potential purposes need to be thought out carefully so the building can function efficiently in multiple different ways. • Three-dimensional symmetrical and asymmetrical design aspects, both vertical and horizontal. Walkways, supporting pillars, and even the choice of seat color can introduce subtle imbalances and breaks that enhance the overall symmetry of the building. Creative architects often incorporate asymmetrical elements as a way of demonstrating their artistry and skill. Great buildings always have design elements that keep them from being too predict- able even though the overall effect is a harmonious one. • Placement of design elements is considered to be part of the syntax of a building. The style of a stadium is determined by how the elements are CONSTRUCTION continued on page 16 combined, as well as by its structural expressionism and its use of green, sustainable architectural solutions. Curved surfaces, frames, lattices, pillars, proportions, roofs, and the use of light and shade, refraction, and diffraction, and passive ventila- tion can all be used to good effect. • The heart of the stadium is obvi- ously the center where performers, employees, and audiences will all focus most of their attention. It is important that the stadium be an im- pressive, creative, and living space even though the basic concept of an open-air building with concentric seats around an oval or round cen- tral arena dates back to the Romans. The introduction of technology in the form of camera sensors that have to adjust rapidly when an athlete runs from sunlight to strong shadow has made it necessary to include techni- cal innovations such as retractable roofs or transparent, tent-like covers that provide shade and absorb heat and radiation. • Each stadium has a setting, and there should be a harmonious re- lationship between the building and the city surrounding it. Any major building can act like a catalyst for urban renewal, and stadiums that have become urban icons certainly qualify. Some of the construction ma- terials used to build stadiums and other buildings throughout the world are remarkable: • In Athens, the Olympic Sporting Complex was refurbished for the 2004 Summer Olympics by the controversial Spanish architect and engineer Santiago Calatrava. As part of his work, he used poly- carbonate panels to create a roof for the Spiridon Louis Stadium that would provide shade for 95 percent of the seating area and absorb 45 percent of the heat and radiation from the sun. Why polycarbonate? It is half the weight of glass, but it is also 200 times stronger. Two bent leaves, each of which has a steel arch to support it, are joined at the ends and are designed to cover 253,000 square feet even though they still leave some of the playing field uncovered. • Beijing’s stadium for the 2008 Olym - pics was designed by Herzog & de Meuron to be as ecologically friendly as possible. It has a collection sys- tem for water, a translucent roof that can be opened, and a passive ventilation system. The grid-like for- mation is a cohesive system where the stairs, wall, and roof all work in such a way as to combine both struc- ture and façade. Wind, weather, and sunlight can all be regulated within the façade by a cushion system that also provides ventilation throughout the building. The cushions are made by ETFE (ethylene-tetrafluoroethyl - ene), which is a polymer based on fluorocarbons. This material was de - veloped in the 1970s by DuPont and was originally intended as an insula- tion material that could be used for aeronautics. It weighs one percent the weight of glass, costs as much as 70 percent less to install, and can carry 400 times its own weight. The material can be inflated into pillows or spun into thin, structured sheets that are also extremely durable. • Montreal’s Stadium for the 1976 Olympics was the first modern building to implement an ancient solution: an actual retractable roof, very much in the spirit of Rome’s Colosseum. The first attempt was ultimately a failure. A giant orange and silver Kevlar fabric awning that was 60,696 square feet was held up by 26 steel cables, but it wasn’t completed until ten years after the rest of the stadium was completed, and even when it was ready it didn’t work the way it was designed to work. It had problems with mechani- cal failure that involved a 556-foot tower next to the stadium, had rips and tears, and was also expensive: nstruction