Zhangjiajie Glass bridge, China
The glass bridge over the Grand Canyon of Zhangjiajie, China, shows sympathy for nature and incredible fortitude in the face of demanding winds, foot traffic and operating conditions.
At 300 m (984 ft) above the canyon floor, the 385 m (1,263 ft) long and six meters (19.7 ft) wide bridge over the Grand Canyon of Zhangjiajie is the world's tallest and longest pedestrian glass bridge.
The thin horizontal bridge, which incorporates a transparent glass floor and side suspension cables, has been designed to accommodate up to 800 visitors, so the glazing solution deployed by the architects and engineers had to be incredibly robust. For such a demanding application, there was only one real option – the use of laminated glass panels incorporating SentryGlas® ionoplast interlayers from Trosifol.
Offering outstanding immersion within the surrounding canyon and mountains − which were the inspiration for some of the breath-taking scenes in the movie Avatar − as well as an unparalleled view of the canyon floor for walk-on visitors, the bridge also features the world’s highest bungee jump and will serve as a stage for dances, fashion shows and cultural events.
According to the architect, Professor Haim Dotan, founder of Haim Dotan Ltd. Architects and Urban Designers: “Out of respect for the beauty of nature, the bridge had to disappear… this was my challenge in the design process. We therefore put our heart, vision and love of nature into creating a bridge, which had the least impact on the surrounding natural beauty.”
“We immediately conceived the glass floor,” he continues, “in order to make the bridge transparent. A structural girder design, suspended from cables, was devised to eliminate the need for bulky three or four meter (9.8 to 13.1 ft) bridge beams and to create a slim profile with a girder beam depth of just 60 cm (23.6 in) for a 400-meter (1,312 ft) span length – a record in Chinese engineering and bridge technology. In order to further integrate the bridge into the surrounding nature, the four suspension towers are covered with trees and plants, assimilating them into the green canyon cliffs beyond.”
The project, which was developed by the Zhangjiajie Grand Canyon Tourism Management Co. Ltd. in collaboration with the architects and structural engineering firm BRDI − China Railway Major Bridge Reconnaissance & Design Institute Co. Ltd., incorporates glazed elements comprising large 3 x 4 m laminated glass panels. At 50 mm (1.97 in) thick, the panels are made of three layers of 16 mm (0.63 in) low iron glass, with two layers of SentryGlas® interlayer sandwiched between them.