The Beijing Olympic Stadium (Bird’s nest) is a perfect exemplar of an architectural marvel built into a firm lattice structure comprised of steel and concrete. This is a marvel of architecture that coalesces the façade and the structure to precipitate it into an aesthetic uber-green structure. The stadium consists of intricate systems of steel condensed into a conceptually simple creating a spatial effect laced with beauty. This is because apart from the steel beams serving their core purpose as structural, they double as aesthetic in their purpose. This holistically brings out the stadium as a gigantic sculpture. This case study will focus on all facets of architecture and the that spans from structural design, energy efficiency and environmental friendliness.
The breathtaking landmark building was designed by two Swiss architects De Meuron and Herzog. The two architects are winners of the coveted Pritzker Prize. The cotemporary architect does not work alone, therefore they sourced for assistance to supplement their final design. They worked in collaboration with two firms: Arup sport and China Architecture Desing and Result Group. A stylistic consultant known as Al Weiwei of Chinese origin was incorporated into the designing of the stadium. Theme of the stadium is Heaven and Earth. The heaven part of the symbolism is represented by the stadium’s circular shape. The roof assumes the symbolic role of the celestial vault to the expanse of the universe in this case. Additionally, the overall shape of the roof was drawn from the yin and yang philosophy of the Chinese; it symbolised harmony and balance. This roof constitutes of 5 circles that map to the fundamentals of Chinese philosophy that has five elements. It also doubles us as the known 5 rings that form the Olympic rings symbol (Flickr, 2010).
The stadium is the world largest lattice steel structure measuring 330 m in length, 220 in breath and 69.2 m in height. The stadium’s gross floor area is 250,000m2. /It is imperative to note that the unwrapped steel used in the construction of the elliptic structure measures 26Km in length. Furthermore, the total weight of the steel used weights 42,000 T. The structure has a total volume of 3million cubic meters and a capacity of 91,000 albeit this was curtailed to 80,000 in the wake of the Summer 2008 Olympics. The construction took place between December 2003 and opened in June 2008pomn costs amounted to the tune of £ 300 million (Pilloton, 2007).
Overview of the lattice steel structure’s architecture
The architectural team gave precedence to designing a structure that avails a splendid view, serene atmosphere that struck a delicate equilibrium with the exceptional elegance and design of the building. They also ensured that they were in tandem with the requirements of the International Olympics Committee (IOC). As well as the International Amatuer Athletics Federation(IAAF). These are the imperceptible complexities that come into play in architectural designs: conforming to rules set by other regulatory bodies that are out of your jurisdiction. The importance in the planning can be exemplified by how importance the architectural design could affect the seating capacity. If the height of the very first row was altered by a mere 100mm, the overall seating capacity would increase since it would become significantly larger. The fiscal implications of such a minor alteration would translate to several pounds to the tune of millions shops (Beijing Municipal Commission of Urban Planning, 2002).
The utility of a parametric software as a tool fore design was of paramount importance and instrumental in the architectural success. It facilitated the drawing of the sight lines, design of the stadium’s bowl geometry, execution of seismic studies, the external envelop design drawing as well as the provision of airflow channels that ensure the grass in the stadium remains green. The architects and engineers employed computational fluid dynamics (CDF) in the design of the stadium. This was instrumental in determining the efficacy of the ventilation system by simulating a games-time environment.A typical game environment consists of spectators and weather elements like wind ant varying speeds, rainfall and sunshine. From this, it was possible to calculate the speed of airflow was well as the temperature variations on every angle of the stadium structure. As a result it was possible to optimise the ventilation system to appropriate levels of operation shops (Beijing Municipal Commission of Urban Planning, 2002).
The rudimentary structure that is seen on the surface is indisputable simple. However, the fine details of its actual geometry are intricate and complex in unimaginable proportions. This translated to a myriad of calculations that were so complex that it require the utility of a software to solve them. IT is imperative to appreciate the fact that in order to construct the twisted structure of the outer steel section of the stadium, a computer software was used to develop, design and build it. This ensured that each and every column and beam had a surgical precision fitting to the other. This was necessary given the complexity involved in the convoluted and twisted design of the steel used to give a perfect fit. The randomness that may be presumed is grossly erroneous swine the “nest” section of the structure holistically employs all the relevant geometrical rules(Beijing Municipal Commission of Urban Planning, 2002).
The nexus of the construcion of such an imposing structure was not to digress from environmental friendliness hence the employment of natural ventilation. It also incorporates massive window shades in its design to auto-control and harmonise the stadium microclimate with that of the environs. In the air conditioning as well as the heating system is holistically computerised to realise the highest efficacy of power utilisation. To augment energy efficiency, geothermal sources of water have been incorporated for the purposes of heating during winter as well as for heating water. In the same breath of environmental friendliness, the water used for construction was tapped from collected rain water. Some sections of the stadium fully run on solar power to bolster the eco-friendly effect of the stadium. The fire extinguishing systems that were installed categorically excluded feron gas as an extinguishing agent. This was to make the fire extinguishing equipment installed environmentally friendly. This averted a scenario of overstretching Beijing’s water supply for the purposes of the construction of the stadium (The Beijing Guide, 2004).
Structure and Design
The design colloquially referred to as the bird’s nest was actually accrued from the assiduous study and observation of Chinese ceramics. It is comprised of grid like formation that boasts of dual functionality of façade and structure. This is by the way it seamlessly coalesces the roof, the staircase and the walls into a single system that is unequivocally cohesive. The undulating wave like design on the edges hence the rows appear as if they are staggering. This design ensures the spectators regardless of their location in their stadium; they are at an even fixed distance from the center of the field. This design is expeditious to the intensity of a competition since it simulates a stage like presence of audience in the mind of the athletes who picture themselves as actors(Pilloton, 2007).
The focal point in the design still remains to be spectator stands. The design therefore borrowed heavily from Roman and Greek classical architecture. Therefore both the west and East sections of the structure are higher that the southern and northern section of spectator stands. The desired effect that is achieved in this case it to bestow spectators on all stands favorable sightlines. The bowl structure of the stadium is partitioned into eight segments that are autonomous. To arrive at this design, the architects employed steel beams that formed a lattice structure with the nexus of obscuring the supports for the stadium’s retractable roof. It is imperative to bear in mind that due to safety reasons, the retractable roof was omitted from the final design. The stadium being devoid of a retractable roof predisposed it to offering better resistance to seismic activity since it became lighter in weight. This called for the alteration of the stadium’s upper section in a bid to protect the fans from harsh weather elements (Pilloton, 2007).
The roof is characteristically comprised of a double membrane: one transparent the other is translucent. ETFE and PTFE were used respectively. The architects employed the use of ethylene tetraflouroethylene (ETFE) as the transparent cover. ‘This roof is predominantly supported of the ground by 18 supports of steel columns. The technique use entails the use of suspension cables akin to the suspension bridge mode of construction. This makes the longest section of the roof from end to end to measure 665m. This plastic is tough akin to Teflon in physical strength resistance and flexibility. Its light weight since it is 1% equivalent to the weight of glass of a similar volume made it an appropriate choice (Pilloton, 2007). Furthermore, It has superior light transmission properties to glass. Due to this, it allows maximum of 50% of solar radiation into the stadium which makes artificial light unnecessary during the day. The ETFE roof offers excellent insulation properties. The insulation property was a plus since it ameliorated the energy costs by 30%.This omission and alterations made accentuated the bird’s nest look of the stadium. A cost benefit analysis reveals that the omission of the roof had positive pecuniary implications since it cut the construction budget by about £ 241 million. It is worthwhile to note that the framework at the top is firm enough to support solar panels on the roof of the stadium (Beijing Municipal Commission of Urban Planning, 2002).
The second roof membrane known as polytetrafluoroethylene (PTFE) was installed on the lower section of the roof. This acoustic ceiling formed by PTFE comes into contact with the inner ring of the stadium as the point of attachment. As a whole the sliding roof is categorically considered to be an integral constituent of the steel lattice structure forming the stadium (Beijing Municipal Commission of Urban Planning, 2002).
The stadium is comprised of two independent structures: a steel frame on the outer section and a inner section of concrete designed like a bowl. These two distinct structures are a uniform distance of 50ft apart. The reason for its final design can be reiterated to be an attempt to obscure the retractable roof. Another reason is to provide strength to the building since the stadium is situated in a highly seismic region. As a result an ostensibly random steel network was developed as a reinforcement. This additional steel comprised of cantilevered trussed steel columns totaling to twenty four in number. These trussed columns were incorporated into the design in order to encase the concrete bowl. Each of these stteel columns weighs 1,000tons and the replication of this design makes each half of the structure identical to the other. This is despite the illusionary random appearance in the pattern of the steel lattice (Desingbuild-Network, 2010).
The lattice work which is the predominant part of the stadium characteristically beams and columns in criss-cross design. The pattern moves both inwards and outwards of the building to create strength. It is worthwhile to note the inclination of the façade was at 13° at the external surface in relation to the vertical (Desingbuild-Network, 2010).
In an analogous fashion to the bird’s nest, the filling of the spaces inside the structure are filled with EFTE cushions that are inflated. This is the same manner in which real birds furnishes cushioning filler material to the space in between the network of interwoven and twisted twigs. The cushion feature is one of the most interesting features of the structure. The roof section of the structure has ETFE cushions installed. Their mounting will be done outside section of the steel structure. This effectively makes the roof of the stadium weatherproof . It serves as a rain water collection mechanism given its sloping feature and filters UV radiation that penetrates into the stadium (Desingbuild-Network, 2010).
On the façade section of the steel lattice structure , another set of ETFE cusho\ions are installed. This time round, the mounting is done on the inner side of the lattice netweork of steel. The installation of the inflated ETFE cushion is strategically done only in necessary sections of the structure. The reason for this is to provide protection of the structure from strong winds. Some sections of the façade remain uncovered with ETFE cushions to facilitate free and natural flow of air . This ventilation system saves on money and energy considering that certain sections of the stadium serve as restrooms, restaurants and even shops ( Beijing Municipal Commission of Urban Planning, 2002).
In order to lower the costs of the constructional the stadiums structural elements are an integral part of it. The ramifications of this technique are that it eliminates the use of towers as well as cable nets. To minimise expenses on the construction, the bowl concrete was made from pre formed concrete. These slabs were separately cast and ferried to the site where they were seamlessly assembled to form a continuous concrete bowl. This also makes the process of construction less cumbersome. From an architectural perspective, it is easier to visualise and design a set of pre-formed concretes which would later assembled be assembled (Pilloton, 2007).
The vast expanse of the football field measuring 8,000m2 was utilised to provided ample space for the underground system of pipes. It is worthwhile to note that the football turf is the first mobile turf in stadium construction. This provides ample room for the installation of other stadium components and equipment beneath it. This network of pipes served as part of the geothermal heat pump (GHP) system. This is where the geothermal energy used for heating parts of the stadium and its pool is harnessed. This system serves as an important heat source for heating the stadium during winter. The mechanism of heating is through absorption of the heat channeled through the pipes by the ground. The heat is distributed by a ramified network of pipes to heat different sections of the stadium. The GHP system also works in reverse during summer. During this time, the coldness of the football ground which is stored in the soil on which the grass grows is disseminated to regulate the high summer temperatures (Beijing Municipal Commission of Urban Planning, 2002).
It is very clear that it involves more than architecture to construct a complex structure in the contemporary field of construction. The architect is bound to liaise with other contributors who may include designers, stylistic consultants and engineers and even fine artists in order to incorporate all the elements expected to be represented in a building. Technology has stamped its authority in the development of lattice steel structures and its complexity is intriguing. It is imperative for every architectural design to consider eco-friendliness of the structure. The environmental impact of such structures can be devastating to the environment. The microclimate created by mega structures such as the lattice steel structure in question. The spectators are able to enjoy natural sunlight and wind whilst inside the stadium just as they would outside. The safety precautions including safety from seismic events, fire outbreaks and other catastrophes is an important facet that must never be neglected by an architect. A building can only be described as efficient if structural and aesthetic functional not dormant or infringe into each other in a detrimental way. The ability to merge the two as in the case of this lattice structure is exemplary. It is important to remember that efficiency can be augmented if there is proper utility of space and modalities of energy saving are in place.
Adhering to the tenets of architecture, employing technology coupled with ingenuity guarantees to produce n almost flawless structure as this one. It is important to reiterate that the choice of material determines the quality and durability of a building. The “bird’s nest” is a perfect exemplar of an insidiously designed a structure that whose choice of material was meticulously done. The Beijing Olympic Stadium embodies all the positive attributes that an architect should consider when designing a structure.