National Centre for the Performing Arts (China)

National Centre for the Performing Arts

The exterior of the NCPA is a steel structural shell. It has a semi-ellipsoidal shape. The length of the long axis in the east-west direction of the plane projection is 212.20 m (696.2 ft), the length of the short axis in the north-south direction is 143.64 m (471.3 ft), and the height of the building is 46.285 m (151.85 ft), which is slightly lower than the Great Hall of the People by 3.32 meters. The deepest part of the foundation reaches 32.5 m (107 ft). It is as tall as ten floors. The large theatre shell is made up of more than 18,000 pieces of titanium metal plates, covering an area of more than 30,000 m² (320,000 sq ft). Of the more than 18,000 pieces of titanium metal plates, only four are the same shape. The titanium metal plate is specially oxidized, and its surface metallic lustre is very textured and has a consistent colour for 15 years. The middle part is an involute glass curtain wall, which is made up of more than 1,200 pieces of ultra-white glass. The ellipsoidal shell surrounds the artificial lake, with a surface area of 34,300 square meters, all channels and entrances located below the water surface. Pedestrians need to enter the performance hall from an 80-meter underwater passage.[5]

The National Centre for the Performing Arts and the Great Hall of the People

NCPA located on the south side of Chang'an Street, in the heart of Beijing. According to the requirements of Beijing's overall planning, the height of the NCPA cannot exceed the height of the Great Hall of the People(46 meters), but the functional requirements of the NCPA exceed this, requiring underground development. The NCPA extends ten stories underground, making 60% of the building area underground. It is the most in-depth underground project of public buildings in Beijing. The deepest place is 32.5 meters, which is directly below the stage of the Opera hall. The 17 meters underground of the NCPA is the ancient river channel of the Yongding River in Beijing. The underground of the NCPA contains abundant groundwater. The buoyancy generated by this groundwater can support a giant aircraft carrier weighing 1 million tons. Such tremendous buoyancy is enough to hold up the entire theater. The traditional solution is to pump groundwater out continuously, but the result of pumping groundwater is that a 5-km-wide "groundwater funnel" will be formed underground near the theatre area, causing settlement of surrounding grounds, and even ground buildings may appear crack. To solve this problem, engineers and technicians have conducted a detailed investigation and used concrete to pour an underground wall from the highest water level of the groundwater to the 60-meter underground clay layer. This vast "bucket" formed by subterranean concrete walls can enclose the foundation of the NCPA. The water pump draws the water out of the "bucket" so that no matter how the water pumped in the foundation, the groundwater outside the "bucket" will not be affected, and the surrounding buildings will be safe.

The 6,750-ton steel beam frame made the largest dome. The structure of the NCPA is composed of a single curved steel beam. More than 18,000 pieces of titanium metal plate and more than 1,200 pieces of ultra-white transparent glass form a massive shell of 2,000 square meters. The world's largest dome is not supported by a pillar. The outer layer of the dome coated with nano materials, and when the rain falls on the glass surface, it will not leave water stains. At the same time, nanotechnology also dramatically reduces the adhesion of dust.[6]

To test the noise generated by raindrops falling on the domes with ten football fields, the scientists conducted repeated experiments. Experiments have shown that if effective noise prevention is not carried out, the sound in the entire dome will be like a drum when the rain falls. The anti-noise problem between theater to theater and theater to outside is solved by the use of a technique called "sound gate".[6]

NCPA is surrounded by an artificial lake, although the winter temperatures in Beijing sometimes fall below zero degrees Celsius and the lake does not freeze in the winter. It is achieved by the use of a closed circulation system, the constant temperature groundwater injected into the lake surface, so the water temperature of the artificial lake can be controlled above zero degrees in winter.[6][5]

The north gate of the NCPA, which serves as the main entrance

The location, immediately to the west of Tiananmen Square and the Great Hall of the People, and near the Forbidden City, combined with the theatre's futuristic design, created considerable controversy.[7] Paul Andreu countered that although there is indeed value in ancient traditional Chinese architecture, Beijing must also include modern architecture, as the capital of the country and an international city of great importance. His design, with large open space, water, trees, was specially designed to complement the red walls of ancient buildings and the Great Hall of the People, in order to melt into the surroundings as opposed to standing out against them.