'The Water Cube', --- an arup's project

FreddyMusic

http://www.arup.com/eastasia/project.cfm?pageid=1250


The Water Cube


'The Water Cube', National Aquatics Centre, BeijingStart Date: December 2003 | Completion Date: 2006
The National Aquatics Centre, known as 'The Water Cube', will be one of the most dramatic and exciting venues to feature sporting events for the Beijing Olympics in 2008.

The interior of the Centre also makes a strong impression



In July 2003, the consortium of Arup, architecture firm PTW, the CSCEC (China State Construction and Engineering Corporation) and the CSCEC Shenzhen Design Institute (CSCEC+DESIGN) won the international design competition for the National Aquatics Centre for the 2008 Beijing Olympics.

The competition, which was judged by a panel of international architects, engineers and pre-eminent Chinese academics, commenced with submissions from ten international consortia and also involved a public exhibition and vote.
The Water Cube looks set to be ready in October 2007. Both the concrete and the steel structure have been completed, and 500 m² of prototype cladding was installed in April, 2006. The next phase is to install all of the cladding and then follow on with de-propping the internal structure and completing the interior.

The building's structural design is based on the natural formation of soap bubbles



To arrive at the building's structural design, which is based on the natural formation of soap bubbles to give a random, organic appearance, we used research undertaken by Weaire and Phelan (professors of physics) into how soap bubbles might be arranged in an infinite array.
To bring the design to life, the individual bubbles are incorporated into a plastic film and tailored like a sewing pattern. An entire section is pieced together and then put into place within the structure. There are interior and exterior films, and the film is then inflated once it is in-situ. It will be continuously pumped thereafter.
The actual pumping has been sub-contracted, and once the installation is complete the operator will be responsible for both the operation and maintenance of the facade for ten years. This was a key component of the brief and in the choice of contractor.
The project is an opportunity for us to offer our expertise in sustainable services. The building will use solar energy to heat the pools and the interior area, and all backwash water is to be filtered and returned to the swimming pools.
The scheme and design for the project was developed in Australia. The project has now been handed over to a team in Beijing who are taking care of the construction.

[ 本帖最后由 FreddyMusic 于 2007-9-7 17:50 编辑 ]

FreddyMusic

The Giant GreenhouseThe Water Cube is designed to act as a greenhouse. This allows high levels of natural daylight into the building and, as swimming pools are predominantly heating driven, allows the scheme to harness the power of the sun to passively heat the building and pool water. It is estimated that this sustainable concept has the power to reduce the energy consumption of the leisure pool hall by 30 per cent.

Energy – It’s also a smart building The Water Cube's design harnesses solar energy and makes good use of natural light

Aquatics centres require a lot of heating, but by cladding the building in high tech ETFE cushions, it will be a very efficient green house. Twenty per cent of the solar energy falling on the building is trapped within the building and is used to heat the pools and the interior area.
By cladding the building in high tech ETFE cushions, the Centre will be well lit during the day, with appropriate levels of internal daylight, visual connection and visual comfort. Up to 55 per cent savings on lighting energy use can be achieved in the Leisure Pool Hall, with smaller savings expected in other areas.
To reduce the energy consumption of the Centre, the design has incorporated many energy recovery systems, like heat recovery from warm exhaust air for warming up the cold outside air (fresh air supply).
This smart building was designed to have the ability to create a comfortable environment where you want and when you want it.

FreddyMusic

3D isometric view of the structural model


The StructureA New Beginning in Design ThinkingThe National Aquatics Centre in Beijing marks a new beginning in design thinking. This new thinking has been spurned on by one question: “How does structure fill space?”
A close up of the Water Cube's innovative steel structure



The structure of the Water Cube is based on the most effective sub-division of three-dimensional space - the fundamental arrangement of organic cells and the natural formation of soap bubbles. It will be clad in ETFE foil cushions which have excellent insulation properties and will create a greenhouse effect.
Arup based the structural design on Weaire and Phelan’s (Irish Professors of Physics at Trinity College) proposed solution to the problem of “What shape would soap bubbles in a continuous array of soap bubbles be?” This problem was both initially posed and tentatively answered by Lord Kelvin at the end of the 18th century but it was 100 years before the Irish Professors proposed a better one.
How the Structure Developed – Key ConsiderationsThe structure

• The wall cavity is 3.6m deep and the cavity forming the roof is 7.2m deep
• The structure is made of approximately 6500 tonnes of steel
• There are 22,000 steel members and 12,000 nodes
• The steel beams would stretch for 90kms
• The structure of the building is so strong that it can be stood up on its end and retains its shape
• The overall size will be 177x177x31m

An ambitious project, one of the first problems was designing a 22 000 beam structure for 190 loading conditions, where every single beam needed to be as small as possible to minimise steel tonnage. The need to minimize steel tonnage is because in long span roof structures, self-weight is critical.
The roof spends a lot of its strength simply holding itself up.
Another challenge was the need to fulfill all of the seismic design requirements of Beijing. The key question is whether to design the roof with compact sections to behave plastically under seismic loads, or whether to use stiffened slender sections to behave elastically under the loads.
To determine which system to use, a world first analysis in inelastic cross-section buckling was undertaken using key techniques developed by Arup. The final tender solution adopted compact sections, which allowed plastic ductility to be taken advantage of under level three seismic loading

FreddyMusic

Arup technology is making the Water Cube a reality

The Technology Creating the geometry and centreline model

Rapid prototypingRapid Prototyping was used to physically model the complex structure both to convey the idea to the judges of the design competition and to better understand it ourselves. Arup used two separate types: sintered nylon powder and solidified epoxy resin.
For the epoxy models: * a large vat of epoxy (about 500mm cubed) sets under UV light

• a metal grating is placed near the top of the epoxy and a UV laser traces a pattern on the plattern
• everywhere the laser focuses, the epoxy solidifies, the laser solidifies pieces that are around 0.1mm cubed, the plattern drops 0.1mm and the laser ''writes'' the next 0.1mm thick layer

Our model is bigger than the machine and was made in four parts, which were then glued together. They are:

• 24 000 elements and about 12 000 nodes
• each element has six faces and each node has 36 faces
• each face comprises two triangles so we have more than one million surfaces to define

New technologyStructure Optimisation Program: Arup developed a structure optimisation program, which carried out the structural analysis, optimisation and design.
The iterative procedure would determine the minimum size of each member that satisfied all design constraints, resulting in the minimum structural self weight.
During the optimisation phase, 22 000 steel members under 190 different load cases were tested. Its job was to test for possible scenarios, challenging it to make the steel structure strong, but as light as possible. The benefit of an automated program is that it allows for the process to be repeated allowing many design options to be considered quickly and accurately.
CAD package – conversion program: To guarantee that all the elements within the structural analysis model were imported correctly to the 3D CAD model, Arup created a conversion program run from within our CAD package. The program modeled the entire structure in 25 minutes rather than months. From that fully coordinated 3D CAD model, we were able to extract all of our elevations, sections and details to produce our final documentation drawings.
Three dimensional wire frame models were then made and saved to 3D AutoCAD electronic models. This allowed the client and potential contractors to see every object within the building with its relevant information.

FreddyMusic

Analysis of smoke movement in the Aquatics Centre

Protecting 'The Water Cube'Fire Engineering’s Crucial RoleWithout Arup’s fire engineers, the Water Cube’s structure as we know it could not have been used as the National Aquatics Centre for the 2008 Beijing Olympics.
After the innovative design was voted the winner of an international competition judged by the people of China, the challenge for Arup Fire and the design team was to demonstrate that the design provided for an acceptable level of safety.
As the Water Cube did not follow the prescriptive rules of the Chinese Building Code, this involved complex analysis, the use of research data, detailed reporting, and presentations to the Chinese authorities.
The fire engineering design received formal approval in early 2004. It is the first Olympic site in Beijing to receive approval for the fire engineering, and has set a precedent and direction for future Olympic projects in the area.
The Innovative Facade - ETFEETFE, the innovative material being used as the 'skin' of the Water Cube, is an amazing material with excellent insulation properties, however it is combustible.
As the Chinese Building Code does not allow for the use of combustible materials for façades, Arup Fire needed to address concerns about its performance in fire, the potential fire scenarios, and the consequences for safety. This allowed the development of appropriate criteria for material selection to provide an acceptable level of safety.
The greatest attribute of ETFE in fire is that is shrinks away from a fire, thus effectively ‘self-venting’ and letting smoke out of the building.
Keeping People SafeIt is estimated that 20,000 people, including spectators, athletes, officials and support crews will use the Water Cube at any one time during the Olympics. To cater for these numbers, the Chinese Building Code would have required 200 metres of exit doors, the equivalent of two sides of the building. Not only would this have significantly impacted on the architectural look of the Water Cube, it would have been a security issue.
Knowing that people prefer to enter and exit from the same place, the fire design encompasses open circulation routes rather than enclosed circulation routes, and incorporates appropriate fire safety systems like sprinklers and smoke exhaust. This makes the building safer for longer and allows the more open and familiar circulation routes to be used for egress.
The egress and circulation routes were specifically designed to maximise net lettable area, provide pleasant and efficient open circulation routes, and minimise external doors adversely affecting the external architecture.
The fire engineering has delivered the best of both worlds. The Water Cube retains its architectural integrity and is a magnificent venue for users, all within an environment that leads in fire safety performance.

hero1_1985

Unbelievable