In determining the ideal location to build structures like skyscrapers, wind farms or bridges, expensive boreholes are usually drilled in order to define the structure and solidity of the subsurface. Master’s student Teus van Dam researched a different method that requires fewer boreholes. This earned Teus the title of Best Graduate 2022 at the Faculty of Civil Engineering and Geosciences.

Less CO2 emissions

The research of Teus has the potential to help make the world a better place. “About percent of all CO2 emissions on earth comes from cement production. Having a clearer picture of the subsurface could possibly avoid the production of unnecessary concrete foundations and this would indirectly positively affect the climate. Limiting the number of holes to be drilled also avoids CO2 emissions. Every little bit helps in the end.” 

Accurate subsurface and soil surveys indirectly contribute to reducing CO2 emissions from cement production.

Teus van Dam

Best Graduate 2022 of the faculty of Civil Engineering and Geosciences

Advanced technology for subsurface and soil research

Using mathematical methods co-developed by TU Delft, Fugro, a geodata specialist, developed an advanced technology for subsurface and soil surveys: Ambient Noise Seismology  which has been used since 2016. Teus van Dam says that “This technology can be used by project developers to do things like decide where to put the foundation piles to ensure a the safest and most sustainable construction possible. Fugro saw the potential of further developing this technology with TU Delft, and I got the opportunity to do this research. I had read about SWANSTM before and thought it would be wonderful to bring this technology a step further in a way that meant it could be applied straightaway. It was also a great ending to my two year master’s in Applied Geophysics which involved 20 other master’s students and myself at TU Delft, ETH Zurich and the RWTH Aachen University.” 

How does SWANSTM work?

Before Teus talks about his research, in which he was supervised by Assistant Professor Kees Weemstra, he explains how SWANSTM works. “The technology measures the speed of seismic S-waves  in the ground. By measuring the speed at which the seismic waves spread and ‘recalculating’ them to depth, using a mathematical formula, you collect information about the ground. You can then decide where it is safe to build.”

It can be done more smartly

He continues. “Research into the ideal site for construction is expensive and takes time because of the boreholes that are needed. My research was to see if there was a way to reduce the number of boreholes.” 

High resolution

Teus used this new code in an existing algorithm. He adjusted the code so that the properties of the ground could be determined in an efficient manner: high quality and speed to process the information. 

A hard pill to swallow

He makes it all sound really easy, but Teus unexpectedly had to learn a completely new programming language to be able to actually use the code. “I worked with Python during my bachelor’s and with Matlab during my master’s. But halfway through my thesis I discovered that I had to write parts of the code in Fortran. That was a hard pill to swallow. Luckily it was not that bad and I quickly learned how to use Fortran. The biggest calculation that I did ran for three solid weeks on my computer. It was a very tense time! I didn’t know if it would do what I expected and if not, what the problem would be. You only need to make one typo while inputting hundreds of numbers and it wouldn’t work. Luckily, three weeks later the right result rolled out. And yes, I then had a little beer with my fellow students.”

A ten

The Board of Examiners praises the speed in which Teus was able to comprehend, implement and expand the current theory on ground vibrations so quickly. He earned an exceptional 10 and the Best Graduate of his Faculty title. “When I heard that, it seemed so unreal and it took a while before it finally sank in. Of course I’m really happy with it.”

Supervising new masters

For now, Teus has plenty of challenges in the next chapter of his career within his job at Fugro. He started working as a Borehole Geophysical Logging (BGL) Engineer on a research vessel owned by Fugro Netherlands Marine in October. “I am doing geophysical research on the best location for a wind farm on the west coast of Ireland. Apart from that Fugro also asked me to supervise new master students in two follow-up research pieces that build on my master thesis. I’m looking forward to it. The research looks at how you can take account of the topography, such as valleys, hills and dams, in the calculation methodology. 

“It would be nice if, in the future, we could identify weaknesses in a coastline more quickly through subsurface and soil surveys”

Teus van Dam

Best Graduate 2022 of the faculty of Civil Engineering and Geosciences

Going abroad

“If I want to continue working in this niche in geophysics, I will probably have to work abroad a lot,” says Teus. “Much research is being done in countries like Canada, Australia and the United States. By coincidence my girlfriend is Canadian. I met her two years ago at TU Delft and she will graduate in geosciences this year too. That makes it even more attractive to go and work there.”