Construction

China’s first 3D printed retractable bridge unveiled in Shanghai

A 3D printed retractable bridge has been unveiled in Shanghai, China, that is capable of unfurling in less than one minute. 

Reportedly the first of its kind to be built in China, the Bluetooth-controlled bridge spans nine meters long and is located in the city’s Wisdom Bay Innovation Park.

The successful manufacture of the bridge is seen as a step towards further advances in 3D printing technology for retractile architecture.

The 3D printed retractile bridge in Wisdom Bay, Shanghai. Photo via Yu Xi / Global Times.
The 3D printed retractable bridge in Wisdom Bay, Shanghai. Photo via Yu Xi / Global Times.

Wisdom Bay’s 3D printing credentials

Shanghai’s Wisdom Bay is built on the former site of a wool textile mill and is home to more than 300 global companies that engage in 3D printing, intelligent micro-manufacturing, virtual reality (VR), augmented reality (AR), and artificial intelligence (AI) robotics projects. The site is also supposedly home to the world’s only 3D printing museum. 

Wisdom Bay has played host to several innovative 3D printing projects in recent years. In 2019, a 26.3 meter-long and 3.6 meter-wide 3D printed concrete bridge was installed in the park. Hailed the world’s largest at the time, the bridge was 3D printed by Tsinghua University in 450 hours. 

At the beginning of this year, another project carried out by Tsinghua University saw the successful construction of a 3D printed concrete bookstore in the park. The bookstore was printed on-site in three weeks using “fiber concrete” to withstand compression and earthquake effects and has a floor space of 30 square meters.

Rendering of the 3D printed bookstore. Image via Wisdom Bay Innovation Park.
Rendering of the 3D printed bookstore. Image via Wisdom Bay Innovation Park.

The 3D printed retractable bridge

Weighing just 850 kilograms, the retractable bridge is nine meters long, 1.5 meters wide, and 1.1 meters high. The structure has been installed over a small pond in Wisdom Bay and is reportedly capable of holding up to 20 people at a time.

The bridge is made up of 36 3D printed triangle panels, each of which features a different design resembling ripples spreading outwards. Printed over three days, the panels are made from a composite carbonate polyester material that is claimed to be environmentally friendly. 

The bridge is divided into nine segments. The retractile element of the bridge is operated via Bluetooth, with the structure unfurling across the water in a spiral shape in less than one minute. The bridge is also equipped with a gravity-sensitive automatic warning system to prevent over-loading. 

The bridge is reportedly due to open to the public at the end of July.

The 3D printed retractile bridge in operation. Video via Global Times.

Bridging gaps with 3D printing

Thanks to its ability to yield improved material efficiencies, cost reductions, and time savings, additive manufacturing is being increasingly utilized for the construction of bridges, viaducts, and other civil engineering projects across the globe.

Elsewhere in Shanghai, a 15.25 meter-long pedestrian bridge has been 3D printed as part of a project carried out by Chinese construction firm Shanghai Mechanized Construction Group Co and 3D printing filament manufacturer Polymaker. The bridge was created as a demonstration of pollution-free construction and the use of “smart” technology.

Europe is also leading the way in leveraging 3D printing’s architectural potential. Last year, global nutritional science firm and materials producer DSM was involved in a project to 3D print a footbridge from recyclable source materials. Installed in the heart of Rotterdam’s Kralingse Bos park district, the bridge was the first to utilize fiber-reinforced thermoplastics. 

Meanwhile in Paris, a consortium including large-scale 3D printing firm XtreeE was awarded a design-build contract for a 40-meter pedestrian footbridge made from 3D printed structural concrete in preparation for the 2024 Olympic Games.

Most recently, construction firms BAM and Weber Beamix announced they had begun building the world’s longest 3D printed concrete pedestrian bridge in the Netherlands, which will stand at a length of 29.5 meters once complete.

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Featured image shows the 3D printed retractile bridge in Wisdom Bay, Shanghai. Photo via Yu Xi / Global Times.