Graduate Member, Coco van Egeraat, has been a structural engineer for three years, since graduating from Imperial College in September 2013. Here she discusses what inspired her to become an engineer, and her work on the Woodchip Barn - a student project to design and build a structure that exploits the natural strength of Beech trees’ Y shaped fork junctions. The project has been shortlisted in The Structural Awards 2016 ‘Sustainability’ category.
Both my parents are architects, and when I was a child they would take me to visit interesting buildings, which inspired me from a young age. After high school I took the Trans-Siberian and Trans-Mongolian Express from Moscow to Beijing, where I visited amazing buildings like the CCTV Headquarters. After completing my Bachelor’s degree in Theoretical Physics, I decided to do an MSc in Structural Engineering.
I am lucky to have already been involved in a great variety of projects. Since starting at Arup, I have already seen through two smaller projects at Hooke Park, a woodland owned and managed by the Architectural Association (AA), where sustainable and experimental construction is promoted using locally sourced timber from the surrounding forest. In addition I have worked on the ‘Garden Bridge’ project in London, as well as a humanitarian project to assess the structural safety of clothing factories in Bangladesh.
The Woodchip Barn Project saw the Arup team (Francis Archer, Naotaka Minami and myself) work together with a group of five AA students (Mohaimeen Islam, Zachary Mollica, Sahil Shah, Swetha Vegesana, Yung-Chen Yang) and their tutors (Toby Burgess, Charley Brentnall, Martin Self and Emmanuel Vercruysse).
The idea for the project came from the students’ reading: an article studying the anatomy of tree forks got them interested in using the trees’ natural bifurcations, which provide a structural connection ‘for free’ (instead of bolted and screwed straight elements you find in normal buildings). The natural connection is also completely continuous, making the connection very stiff – which we call a ‘moment connection’.
From the start the students pushed for a really ambitious design that would take advantage of these connections, using 3D scanning to obtain the geometries of all the possible tree forks and create a realistic computer model. An optimisation programme generated possible arrangements of tree sections to form the arching truss, so that we could try out different arrangements and find the most suitable. No two connections would be the same, so it was a challenge to have all connection points meet with minimal tolerance. An innovative solution was the use of a 6-axis robot arm to accurately prepare bespoke connection details.
In a world where sustainability is becoming more and more important, it is an interesting concept to design buildings that take advantage of naturally occurring elements, using the accuracy of 3D scanning techniques. However, using standardised, rectangular elements will continue to have its obvious advantages.
The Woodchip Barn project has enabled us to explore innovative design, 3D scanning techniques, digital optimisation, and robotics, demonstrating the huge potential of timber design and promoting sustainable construction. We’re proud to see it completed and shortlisted for a Structural Award.
Why is timber a sustainable material?
Timber is a sustainable structural material because we can achieve a much lighter building compared to a typical steel or concrete structure, allowing for smaller foundations. Timber can also be considered to have negative CO2 emission over its life, as trees take up CO2 from the atmosphere and emit oxygen.
Finally timber grows naturally, as opposed to steel and concrete, so to manufacture timber elements uses less fossil fuel and emits fewer greenhouse gasses.
Discover more about The Structural Awards