The new headquarters of China Central Television (CCTV) is a 234m tall building with a highly unusual shape, described as a 'three-dimensional cranked loop'. The building is formed by two leaning towers, bent 90° at the top and bottom to form a continuous tube.

As part of the original design team, Arup was commissioned by the architect, OMA, to provide structural, MEP, geotechnical and fire engineering design, as well as security consulting services.

Arup’s diverse role in the project involved co-ordinating design and engineering teams across the firm from London, Beijing, Hong Kong and Shenzhen.

The gravity-defying structure of the building has redefined the traditional form of skyscrapers.

The building’s primary support is achieved through the irregular grid on its surface, a visible expression of the forces travelling through the tube structure; the smaller the diagonal pattern, the stronger the load and the greater the support.

Close-up of Beijing China Central TV Headquarters diagrid support. Credit: Zhou Ruogu Architecture Photography
This diagrid support is visible in the building’s façade, where the pattern reflects the distribution of gravitational forces throughout the building structure

Making the impossible possible

The gravity-defying structure of the building has redefined the traditional form of skyscrapers and posed unparallel structural challenges for Arup’s design engineers, especially the linking of the two leaning towers.
 
With expansion and contraction of the structure caused by Beijing’s extreme hot and cold weather, it was of paramount importance that the new headquarters’ design and engineering should take into consideration the way the building would behave before it was linked together. Arup specified that the joining of both towers had to be done very early in the morning, when both towers would be at a uniform temperature before the sun started to rise and with movements caused by the environment at a minimum.
 
Prior to the joining of the towers, Arup specified five days of monitoring the global and relative movements so the correct dimensions of the linking elements could be correctly predicted. Final adjustments were made to the length of the linking elements before installation, as it was vital that the towers were fixed together within a few minutes. The final join was done at 8am on a cold winter’s day, when the steel was at its most uniform temperature.
 

 

Two leaning towers at Beijing China Central TV New Headquarters
The building is formed by two leaning towers, which are bent 90° at the top and bottom to meet, forming a continuous tube
Exterior view of the Beijing China Central TV New Headquarters shape
The highly unusual shape of the tower redefines the physical form of the skyscraper and posed some significant structural challenges during design
Multiple broadcasting screens inside Beijing China Central TV New Headquarters
The building combines administration functions with news, broadcasting, studios and programme production