3D-printed steel bridge loaded with sensors opens for pedestrians in Amsterdam

The bridge was installed over the Oudezijds Achterburgwal canal in Amsterdam’s Red Light District and was unveiled today (July 15) by a robot.

The project has been in development since 2015 by Dutch start-up MX3D and uses torch-wielding robot welders for its construction. Researchers from Imperial College London (ICL) will now measure, monitor and analyse the performance of the 12-metre-long structure as it handles pedestrian traffic.

The data collected will enable them to measure the bridge’s ‘health’ in real time, monitor how it changes over its lifespan and understand how the public interacts with 3D-printed infrastructure.

The data from the sensors will be put into a ‘digital twin’ of the bridge – a computerised version which will imitate the physical bridge with growing accuracy in real time as sensor data come in.

The performance and behaviour of the physical bridge will be tested against the twin, which will help answer questions about the long-term behaviour of 3D-printed steel, as well as its use in real-world settings and in future novel construction projects.

Before installation, the structure was tested extensively including applying destructive forces on printed elements and using non-destructive real-world testing on the footbridge.

The Steel Structures group at ICL also undertook cross-section testing and computer modelling using the digital twin.

Imperial co-contributor professor Leroy Gardner said: “A 3D-printed metal structure large and strong enough to handle pedestrian traffic has never been constructed before. We have tested and simulated the structure and its components throughout the printing process and upon its completion and it’s fantastic to see it finally open to the public.”

Dr Craig Buchanan, also on the Imperial team, said: “Research into this new technology for the construction industry has huge potential for the future, in terms of aesthetics and highly optimised and efficient design, with reduced material usage. It has been fascinating and we are delighted that the structure is now ready to be used.

“For over four years we have been working from the micrometre scale, studying the printed microstructure up to the metre scale, with load testing on the completed bridge. This challenging work has been carried out in our testing laboratories at Imperial and during the construction process on site in Amsterdam and Enschede, the Netherlands, on the actual printed bridge.”

Professor Gardner added: “3D printing presents tremendous opportunities to the construction industry, enabling far greater freedom in terms of material properties and shapes. This freedom also brings a range of challenges and will require structural engineers to think in new ways.”

The Imperial researchers are part of a wider team of structural engineers, mathematicians, computer scientists and statisticians working on The Alan Turing Institute-Lloyd’s Register Foundation programme in data-centric engineering. The programme is led by Professor Mark Girolami at The Alan Turing Institute.

Professor Girolami said: “3D printing is poised to become a major technology in engineering and we need to develop appropriate approaches for testing and monitoring to realise its full potential. When we couple 3D printing with digital twin technology, we can then accelerate the infrastructure design process, ensuring that we design optimal and efficient structures with respect to environmental impact, architectural freedom and manufacturing costs.”

The data captured from the bridge will be made available to other researchers worldwide who want to work with the Turing researchers in analysing the data.

Steel isn’t the only manufacturing material that is being made compatible with 3D printing technology. Another Dutch firm unveiled 3D-printed concrete homes in April that are designed to be as energy efficient as possible.