Shanghai Tower Case Study

The entire structure of the Shanghai Tower is then encased inside a circular inner curtain wall that rises by 2073 feet. (ref 12) A second ‘skin’ of smooth twisting glass that acts as a direct barrier of the building from smog and extreme weather conditions. (ref 12)

The unique facade design was produced as a joint design by Gensler, the architecture firm that won the international competition to build the Shanghai Tower, and Thornton Tomasetti, an aiding structural engineering company.

Three main design concepts of the outer curtain wall were identified by the Gensler Design Team in order to reduce wind loads under typhoon conditions : tapering shape, rounded corners and an asymmetrical facade. (ref 10)

Fully aware that a ‘twisted building

Usually buildings have only one curtain wall surrounding its core and it is therefore attached to a stable structure. The outer skin of the Shanghai Tower, on the other hand, is 2 to 33 feet away from the core. (ref 20) Also, the conventional way of supporting the weight of this extra layer would be to fill up the the space with steel supports. However, this solution defeats the design team’s objective to have airy sky gardens, not to mention the poor aesthetics when the bulky steel support web is seen. To add to the challenge, a slim-line steel structure is adopted in order to satisfy aesthetic demands, which can easily collapse under its own weight: one floor of the curtain wall weighs 115 tons. (ref

(ref 12) Tower Curtain wall support system (ref 11)

The resolution to this was an innovative use of the scaffold and is named the Flying Saucer: The 100-tonne mobile scaffold first climbs to the top of the section and slides down the core by taking advantage of gravity at a button’s command. The workers can then put in steel ring beams floor by floor and suspending the structure as the moving platform slides down. (ref 12)

A simulation of the Flying Saucer climbing up to the top of a section (ref 12)

Glass types chosen for the two major curtain wall systems are the most technologically advanced glass available. Trial have been undergone for 3 years to maximise protection, minimise reflection, block out glare from the sun whilst allowing light into the sky gardens and stand up to Shanghai’s unique weather and climate. (ref 12) Glass for the exterior curtain wall is 26mm laminated glass assembly and that of the interior curtain wall is 30mm insulated glass assembly, both with low e-coating and around 10mm low-iron glass on either side. (ref