by Jerry Elengical, Samta NadeemSep 23, 2021
Since the turn of the century, the advent of new construction and material technologies such as digital fabrication and 3D printing have eroded the former limits of structural articulation in favour of new paradigms. Among them, 3D printing, in particular, has been adopted in numerous projects that are at the forefront of driving innovation in contemporary architecture - most notably, in the assembly of prototypes for Martian and lunar habitats. Aside from explorations of its applications in extraterrestrial construction, back on Earth, the method has been extensively utilised in the assembly of modular homes, pavilions, furniture, and even installations. However, of late, there is one particular domain of construction where the method has gained notable visibility - that of bridge building. Several such endeavours have taken form in the recent years, most notably in China, which currently hosts both the world’s longest 3D-printed bridge as well as another retractable bridge - both in Shanghai. As the technique begins to spell a new dawn for bridge construction, STIR presents a journey through the evolution of 3D printed bridge structures: from their earliest realisation to the more recent cutting-edge iterations that have cropped up worldwide.
1. ACCIONA 3D-Printed Footbridge by ACCIONA and IAAC (Institute for Advanced Architecture of Catalonia) - Madrid, Spain
Spanish conglomerate ACCIONA were pioneers in the realm of 3D printing bridge structures, having installed the first such structure - a 12m footbridge in Castilla-La Mancha park in Madrid, Spain back in 2016. Consisting of eight 3D-printed micro-concrete modules, that were each nearly two-metre long and 1.5-metre wide, the bridge design features 1.3-metre high railings with organic perforations which add to its structural form. Developed in conjunction with the Institute for Advanced Architecture of Catalonia (IAAC), and the Polytechnic University of Catalonia (UPC), the structure imitates porous surfaces found in its natural context and weighs a total of 30 tonnes. Mariano Martín Cañueto, Head of ACCIONA Industrial’s Structural Engineering Division at the time, and the creator as well as site director for the project, comments on the obstacles faced in bringing the endeavour to live in an official release, stating: “The biggest challenge was dealing with complex geometric shapes that can’t be boiled down to simpler models. We used the calculation of volumetric finite elements (dividing complex three-dimensional shapes into much smaller fragments that can be mathematically analysed) with the ANSYS computer software.” He adds, “The other big challenge was large-scale 3D printing with a new material that had to be characterised.” In resolving these issues while daring to venture into brand new territory, ACCIONA’s bridge is an impressive feat of its own accord - setting the standard for a whirlwind of innovation that would occur in succeeding years.
2. Striatus by Zaha Hadid Architects Computation and Design Group, Block Research Group at ETH Zurich, and incremental3D - Venice, Italy
The product of a collaboration between the Block Research Group at ETH Zurich, Zaha Hadid Architects Computation and Design Group, and incremental3D - made possible by Switzerland)-based Holcim, Striatus is an unreinforced footbridge built from 3D printed concrete blocks assembled in a bifurcating, organic form without the use of any mortar. Exhibited at Venice’s Giardini della Marinaressa gardens during the Venice Architecture Biennale 2021, the bridge is a trailblazer among its kind, blending the modern intricacy of computational design with tried and tested building methods. Striatus’ superstructure weighs 24.5 tonnes, reaching a maximum height of 3.5m, with its longest span extending to 15.10m. Named for the characteristics of its structural logic and fabrication methodology, Striatus possesses a bifurcated deck geometry consisting of striated layers of concrete, 3D printed into a funicular structure that behaves as a set of leaning voussoir arches. This configuration conceptually resembles traditional Roman arched bridges that were built in stone - albeit with a structure that can be installed, dismantled, repurposed and reassembled repeatedly. Head of CODE, Zaha Hadid Architects’ Computation and Design research group, Shajay Bhooshan, states in an official release, “Striatus stands on the shoulders of giants: it revives ancestral techniques of the past, taking the structural logic of the 1600s into the future with digital computation, engineering and robotic manufacturing technologies.” He continues, “Its tactile quality, aesthetics and strength, reflect our principal partner Patrik Schumacher’s vision that beauty is a promise of performance.”
3. MX3D Bridge by MX3D, Joris Laarman Lab, Arup - Amsterdam, Netherlands
Designed by Joris Laarman Lab with structural engineering by Arup, the world’s first 3D printed steel bridge by MX3D - a global leader in robotic metal 3D-printing - was installed in one of Amsterdam’s oldest districts and inaugurated by Queen Máxima of the Netherlands in July 2021. Possessing fluid, undulating geometries and ribbed surfaces resembling something straight out of a science fiction film, MX3D’s ambitious vision was brought to life with the aid of numerous industry-leading companies such as ABB, Air Liquide, ArcelorMittal, Autodesk, AMS Institute, and Lenovo - all made possible with the support of the Lloyd's Register Foundation. With origins as far back as 2015, the final structure spans 12 metres and is printed from nearly 6,000 kg of stainless steel. Joris Laarman of Joris Laarman Lab and Co-Founder of MX3D, reflects on the project in a press statement, sharing, “Right from the first little 3D printed steel blobs that showed we were able to control the process, this felt like the discovery of a new continent of possibilities.” A cutting-edge research project in its own right, the bridge design was realised through methods such as digital twinning, generative design, and IoT (Internet of Things) systems - which analyse data regarding the structure’s performance in the built environment to review the safety of metal 3D-printed structures.
4. Nijmegen Bridge Project by Studio Michiel van der Kley, Witteveen + Bos, Rijkswaterstaat, BAM, Saint Gobain Weber Beamix - Nijmegen, The Netherlands
As the latest addition to this list, the ongoing Nijmegen Bridge Project in The Netherlands is a joint venture between Studio Michiel van der Kley, the Technical University of Eindhoven, and Rijkswaterstaat - the country’s Directorate-General for Public Works and Water Management. Fabricated in striated concrete modules with arched geometries - by the joint lab of UK-based BAM and Saint Gobain Weber Beamix, the bridge, once completed, will be the longest 3D printed cycle bridge in the world. Developed with the aid of parametric design software, the bridge’s structure was modelled by Summum Engineering, based in Rotterdam. A core concern of the design process was to ascertain whether methods such as 3D printing and digital fabrication would allow for greater freedom in design. To this end, the designers sought to explore geometries that went beyond the limits of traditional formwork-based construction techniques, with a gently curving deck held up by vaulted supports. In conversation with STIR, lead designer Michiel van der Kley comments on the project: “Our government is interested in new ways of dealing with the demand for constructing bridges, tunnels and the lot, and they think that automation and digitalisation of the building environment will be the answer. I, on the other hand, would like to try and determine the boundaries of 3D printing with concrete, and hence, these two worlds meet in this project.”
With the encouraging signs of progress on offer in the projects listed above, the future of 3D printing applications in infrastructure development appears relatively bright. In light of the several benefits of applying 3D printing technologies in large-scale construction - such as enhanced efficiency, less material wastage, structural simplification, and potentially lower carbon footprints, the method may yet see the widespread adoption that advocates have been vociferously championing, and furthermore, the changes brought about through the technique’s large-scale implementation could potentially revolutionise the way in which built environments across the globe are planned and developed.