Follow this year's William Chalmers lecturer to the paradise of clay

​Professor Minna Karstunen was already clinging to clay as a child - and it finally led her to Chalmers. At this year's William Chalmers lecture, she talks about how the moveable Gothenburg clay can become a solid foundation for the future.
Minna Karstunen, Professor of Geotechnics at the Department of Architecture and Civil Engineering, is hired as an independent expert in the work with Västlänken and leads the Geotechnics research group at Chalmers.

She laughs a little as she tells about the first memory of her fascination with clay.
“Even as a kid I was very fond of the material, of shaping it. I ran away into a field and made bears out of mud. When I got home covered in dirt my mom got very angry and had to clean me with the garden hose…”
The clay was rinsed from the clothes, but her interest in the material has lived on. After studying geotechnics, and almost 20 years in the UK –  first as a doctoral student in Swansea, Wales and then as academic in Glasgow, Scotland – it was once again the clay that guided her steps. This time to Chalmers.
“For research on clay, Gothenburg is a paradise. Here you have good access to samples and a great lab, I can do things here that weren’t possible in the UK”, says Minna Karstunen.

Lecture on tunnels in quick clay and the Göta tunnel
Minna Karstunen is still in the process of putting her William Chalmers lecture together, but some of the content she can already reveal.
“I will talk about what quick clay and sensitive clay is – and give an example of how well we can do things if we use our best knowledge in soft soil modeling: Götatunneln, which is one of the latest deep excavations in Gothenburg”.
“The big challenge with deep excavations is that you can model how the work will progress before the start, but inevitably there will be changes during the actual construction work – there can always be remains of Dutch settlements showing up. A good thing with Sweden, however, is that at least there are not as many old bombs appearing as in Germany and the UK ...”

Expert for the construction of Västlänken
Minna Karstunen is also an independent geotechnical expert in the construction of the big infrastructure project Västlänken in Gothenburg.
“My role is to ensure that Västlänken is delivered in a technically sound way. It is no problem to build it if you have good predictions and plans for what to do if you encounter foreseen and unforeseen problems”.
Then, what is so special about the Gothenburg clay, this controversial soil that some claim is impossible to build through?
“First of all, there is a lot of clay. It is soft and, in some places, it is also a possible natural hazard. This isn’t a material to play with, and we do not yet fully understand why it behaves the way it does”.
“The Gothenburg clay is special – but not so special. In Mexico City there is a much softer clay and there they have been able to build a subway. Oslo, Helsinki and Saint Petersburg also have similar conditions as here. So Gothenburg is not so extreme”.

Minna Karstunen is very much looking forward to giving a William Chalmers lecture.
“It's an honour, and not something you say no to. What I'm talking about is important for all of us – everything we do needs to be rooted on the ground”.

On Tuesday November 5th Minna Karstunen talked more about her research in her roll as the William Chalmers lecturer of 2019.

Text: Erik Krång
Photo: Johan Bodell

Minna Karstunen…
... is a Professor at the Division of Geology and Geotechnics at the Department of Architecture and Civil Engineering and leads the research group Geotechnics. The focus of her research is the complex rate dependency of the stress-strain response of soft clays. She has previously worked as a Lecturer at the University of Glasgow and ultimately as a Professor at the University of Strathclyde.

Published: Thu 07 Nov 2019.