~UnkNown~

Tuesday, February 23, 2010

Design&Construction of Beijing National Stadium a.k.a Bird's Nest

Located at the southern part of the Olympic Green in Beijing, the National Stadium is the main stadium of the 29th Olympiad in 2008. Occupying an area of 21 hectares, it has a floor space of 258,000 square meters. Its seating capacity amounts to 91,000, including 11,000 temporary seats. It is the world's largest steel structure which cost $423 million. The design, which originated from the study of Chinese ceramics, implemented steel beams in order to hide supports for the retractable roof; giving the stadium the appearance of a "Bird's nest".Ground was broken in December 2003 and the stadium officially opened in June 2008.

The stadium consists of two independent structures, standing 50 feet apart: a red concrete seating bowl and the outer steel frame around it.In an attempt to hide steel supports for the retractable roof, required in the bidding process, the team developed the "seemingly random additional steel" to blend the supports into the rest of the stadium. Twenty-four trussed columns encase the inner bowl, each one weighing 1,000tons. Despite random appearance, each half of the stadium is nearly identical. The upper section of the roof was altered to protect fans from weather. Due to the stadium's outward appearance, it was nicknamed "The Bird's Nest".

To minimize the formwork construction on the bowl, the design team have favoured the use of precast concrete. A terrace of L-shaped precast units spanning areas between the supporting reinforced concrete in situ beams will make up the section of the middle and upper tiers. The stadium will be supported by 24 main columns of 1,000t each, which is far more than the weight of those in a conventional stadium and spaced in what appears to be a random pattern (construction has required 42,000t of steel).

The roof is covered with a double-layer membrane structure, with a transparent ETFE (ethylene tetrafluoroethylene) membrane fixed on the upper part of the roofing structure and a translucent PTFE (polytetrafluoroethylene) membrane fixed on its lower part. A PTFE acoustic ceiling is also attached to the side walls of the inner ring. The membrane covering of the Bird's Nest is curved and double-layered, providing decorative, soundproof, wind-proof, rain-proof, and even UVA protection to its already impressive body.

The spaces in the structure of the stadium are to be filled with inflated ETFE cushions. On the façade, the inflated cushions are mounted on the inside of the structure where necessary, to provide wind protection.

CONSTRUCTION OF HYDROPOLIS UNDERWATER HOTEL

Hydropolis Underwater Hotel, Dubai, United Arab Emirates

Official name: The Crescent Hydropolis Resort

Built : 2009-2013

Cost : $500,000,000

Designed by : Joachim Hauser

Type : Hotel

Maximum depth: 66 feet

Dubai, Hydropolis is the world's first luxury underwater hotel. It will include three elements: the land station, where guests will be welcomed, the connecting tunnel, which will transport people by train to the main area of the hotel, and the 220 suites within the submarine leisure complex. It is one of the largest contemporary construction projects in the world, covering an area of 260 hectares and it’s located at about 20-30 meters below the surface.

Dubai Underwater Hotel is well looked after in many emergency situations with the help of modern technology and innovative equipment. There are a series of watertight doors which allow management of the hotel to completely seal off the entire sections of the hotel complex, in case there is a sudden rupture. The complex is supposed to have its own system of missile which will safeguard itself in any probable case of terrorist attack

The project is divided into three sections. The "land station" is the complex where visitors are first greeted. It is a large building with a roof that dips and rolls like the crest of a wave. From there, people enter a tunnel to begin their journey to the hotel, itself. The tunnel is 1,700 feet long and carries a train beneath both the land and the sea. The destination, of course, is the hotel itself. Mimicking natural forms, it is shaped like a collection of bubbles and curves designed to provide maximum resistance against the pressures of the sea water as well as the occasional typhoon that may stray into this area. It has already been compared to both a jellyfish and a sea turtle. The hotel features a pair of observation domes which allow an expansive view of the water and the creatures that live in it. They are large enough to emerge above the waves, and one has a retractable roof allowing people to be surrounded by the ocean while looking directly into the sky.

From the surface, the hotel has the appearance of a futuristic artificial circular atoll with a low barrier barely rising above the waves. On the inside of that perimeter are the main structures with curving shell-like surfaces at home in the sea.

To enter this surreal space, visitors will begin at the land station. This 120m woven, semicircular cylinder will arch over a multi-storey building

In many areas, it is not easy to see Dubai's sky without at least one crane in your view; some say 16% of the world's large construction cranes reside in Dubai. Construction in Dubai and the UAE in general is being done at a much faster process than in any Western country. This is partly because laborers from the Indian subcontinent accept lower wages than those from other countries.