Zhangjiajie glass bridge: innovation meets architecture

The Zhangjiajie footpath provides impressive proof of how strong glass really is. A case study by Kuraray, demonstrates the interplay of technology and nature in innovative architecture with laminated toughened glass.

Glass is a central design element in architecture – transparent, versatile and high-performance in load-bearing. Be it as large façade glazing or filigree details in interiors. Glass fuses aesthetics with functionality. How much load glass can bear is shown by the glass bridge spanning the Grand Canyon of Zhangjiajie in China. The bridge not only makes for spectacular vistas but also withstands extreme wind loads, high visitor footfall and other physical stresses.

Measuring 385 metres in length, 6 metres in width and being suspended 300 metres over the ground, the Zhangjiajie glass bridge is one of the most spectacular buildings of its kind.

The bridge was designed to carry up to 800 people at a time. The backbone of the structure are large-format glass elements made of laminated toughened glass with SentryGlas® Ionoplast interlayers – developed by Kuraray.

Both the glass elements and bridge structure were subjected to extensive testing to fulfil the extraordinary requirements made on safety and longevity. The glass panels, for example, withstood wind speeds of up to 200 km/h in the wind tunnel of the Hunan University. In load tests involving 20 tons the deflection of the panes was as low as 2.16 centimetres – an impressive value considering the span.

In addition, tests for aeroelasticity, flutter, gravitational rigidity, vibration behaviour and passenger load were performed. On the basis of these studies targeted technologies for vibration and impact dampening were deployed. An important contribution to this is made by the high stiffness of the SentryGlas® interlayers.

The bridge design comes care of Professor Haim Dotan, who paid particular attention to most discreet integration into the landscape possible. “Out of respect for the grace of nature the bridge was to appear as invisible as possible,” says the architect. The slender suspension structure with only 60 cm wide stays foregoes massive columns. Even the bridge piers optically blend with the environment – they were concealed with plants to harmoniously blend with the green rock walls.