Think of a use for a tunnel. Transport, by road or rail, is an obvious one. Water conveyance is another, both bringing clean water to people who need it and carrying foul water and sewerage away. There is also hydropower to generate electricity. Then, add in mining and protecting communication and power cables, and that probably covers around 95% of the tunnelling projects featured over the years in this magazine.
Farming underground has not been seen as a prime use for underground space, and nor have data centres or libraries figured much in thinking of what to strategically place below ground. SCAUT, the Swiss Centre for Applied Underground Technologies, is urging and promoting all of these.
The new Managing Director of SCAUT, appointed earlier this year, is Veronika Petschen. You could call what follows her manifesto, or her life story, or both.
“I am a civil engineer” she says, “I have been working for many years in underground construction, but I got there more or less by accident. I actually started out on bridges and high-rise buildings but specialising in the renewing and reuse of structures; and I learned about tunnels in the refurbishment department of a tunnelling company.”
The company was Amberg Engineering. “A big advantage of that work for me was that refurbishment projects do not normally take as long as new constructions. Big base tunnels for example can stay in the study phase for ten years. But in refurbishment I could experience all the phases of a single project: I could be on the construction site and doing the site supervision on a project that I had also contributed to in the inspection and the study phases just a few years before. It meant I could see a project through from start to finish, and that I could work on a good number of different projects in not too many years.”
“I also became involved in a software project called ‘inspection cloud’ for the inspection of tunnels using artificial intelligence, so I got to know about different aspects of digitalisation, not only Building Information Modelling (BIM) but other solutions as well.
“You don’t use TBMs on refurbishing tunnels, so my knowledge of working with those is more theoretical than practical, but I have become very interested nowadays in aspects of sensors and data-sensing, and in artificial intelligence that might for example help to drive the TBM machines.” A digitisation expert obviously can be more than useful in guiding the course of the industry: “Digital techniques will obviously play an ever-bigger part in tunnelling in the future. I am sure that if digitalisation is well done it can help us to avoid three aspects of waste: waste of time, waste of materials, and waste of information.
“One of the great uncertainties in tunnelling is the geology. The science of geology itself is not going to be digitalised, but digitalisation can help us to visualise and analyse it. I guess that if we put into a single three-dimensional model all the information, all the data from the drilling, from the inclinometer, from the seismic predictions, and also the data that is captured in the construction site itself it will help us to understand more effectively the geological aspects and the difficulties that could occur. The more complicated the geology, the more important it is to have a good model.
“I became more and more involved in innovation and development projects that Amberg was carrying out, and that’s how I came to a project called Tunnel Digitalization Center of SCAUT. The Center has of now around seven companies in the consortium and I was Amberg’s representative in it. SCAUT is an association with 65 members.
“I have been responsible for the digital twin of a demonstration and research tunnel we have, the Hagerbach Test Gallery, in the Swiss Alps. It is a real environment demonstration centre: a real tunnel which also has all the digital working tools that model it which you can study at the same time.” As we shall see, Hagerbach houses other SCAUT projects and activities as well.
“The vision of SCAUT is to be a catalyst in the underground construction industry in order to enable innovation and share knowledge; but we want to be much more than just a body for the industry alone. Most importantly we want to speak to the outside world, to the people who live in our cities and countryside, and to the planners who plan how these places should be. We want to be a competence centre for the use of underground space.”
In other words, it is about ideas for using underground space as well as ideas for constructing it. “We want to find new concepts, new solutions that show how we can use the third dimension that is there right under our feet. Why is that so important? It is because the population of the world keeps growing. The tendency is still that more and more people continue to concentrate in urban areas where space is in very short supply; and on the other hand, if we are not in the urban environment we want to keep the green spaces green.”
There is a huge psychological aspect to this: From the days of dwelling in caves, the underground has had a threatening aspect to mankind, a place of darkness and demons, the approach to the underworld and a place of fear. It is not logical, as a species we should probably have outgrown it, but it is there engrained in the human psyche. “We need to ‘de-demonise’ the space that is underground”
she says. “We want to change this view, because nowadays there are so many purposes, for industry or for infrastructure, that can be sited underground. “People want to live with a view but to go shopping you don’t need a view: shopping malls don’t have windows, so why not put them underground? If you are parking your car you don’t need windows in the car-park. Science labs are closed spaces: even above ground they use artificial light, so why not put those underground?” Not many people love car parks or shopping malls but even spaces that one thinks of as warm and welcoming can go underground: “Libraries, for example; they don’t need to be upstairs either.” If you don’t believe her, read on.
“There are all these things that people can do underground. What we are trying to do is to tell people that there are more uses for underground space that just a rail tunnel or a road tunnel. It is very important for urban planners to understand that they should open the underground perspective.” And the reason is very fundamental: “It is because the space that is above ground is so precious, for living, for nature, and anything that can work well underground should be put there.”
It is clearly a passion. How did she get to this place? “I was born and grew up in a big city, Budapest. I never thought as a child that I would become an engineer; but we lived in the suburbs and my high school was in the middle of the city so I spent a lot of time on public transport. Budapest is a very beautiful city, so each morning I saw these beautiful places, with those backgrounds of gorgeous buildings, spoiled by bus stations, tram stations, cars … And I was already half-thinking ‘Couldn’t we do something that would make the street view a bit nicer? Couldn’t we cover those over?’
“Of course, the obvious answer is to build tunnels. Why build a rail line through the middle of this wonderful architecture when you can put them underneath the ground and keep the architecture as it is?”
A spell in France reinforced the message: “A second very important experience for me was after my first year of university in Budapest when I had the opportunity of studying for a semester in Clermont- Ferrand and as an intern in an urban architect’s office called Blanc et Céleste in Paris. There I learned a lot about how cities work. Paris had 14 metro lines already at that time and I thought how much better it would be if my hometown had the same. Actually, the first underground metro line in continental Europe was in Budapest. It was built in 1896, after London’s first line in 1863. So, Budapest does have metro lines, but not enough of them.
“And in Paris another underground space inspired me. I saw the François Mitterand Library. You walk in the open air, on what is actually a roof; you walk round a space in the middle where there are huge trees growing from ground level and you look down onto the trees, with part of the library beneath your feet. It creates a very beautiful open area where people can just walk around in a very crowded part of the city. I was really amazed at this solution; I thought ‘That is the future!’ Though I never realised then that it would be the future of what I was going to do in life.
“So now I am really happy to have this opportunity of working for SCAUT because it is a platform for innovation of that kind: it can have so much impact, and not only on the underground construction industry: It has macro-social benefits as well, positive effects on the whole of society.”
“At the same time, we must not forget that prototypes or projects have to have very practical triggers or purposes, because for projects to be sustainable they have also to bring a profit or support themselves.
“So SCAUT is a platform for industry and applied technologies. We don’t do basic research, we leave that to the universities, but we do have a practical industry-based trigger, and practical industry-based projects.
“SCAUT is obviously in communication with different industry partners, and we get in touch also with universities. For example, last month we organised a workshop on underground energy solutions, defining what would be the low-hanging fruit for questions like storage of heat, cold or electric energy or CO2. We match science with industry.
“We are headquartered in Switzerland but we are international; you cannot really make innovation without being open to everyone. We have members from Australia to South Korea.
“But we do have very specific projects of our own. We have projects on materials digital tracking and are launching one on 3D printing of tunnel elements.
“Another project is the plug-in cross-cut element. Every cross-connection between parallel tunnels in twin-tube projects needs to be lined with concrete and fitted with safety doors. This takes a long time because in tunnelling we don’t have millimeter-precise ways of working; in natural rock you are doing well to get accuracy down to a couple of centimetres, which means that every cross-cut is slightly different in size and their linings have to be custom made on site. That takes a lot of time.
“But we can take a laser scan of the cross-cut, so we have the exact measurement of each one. We can reproduce that in the factory, so in an adjustable mould we can cast the concrete element precisely to size, with the safety door and mechanism already fitted; and we can transport that prefabricated unit to the cross shaft on rail tracks and just plug it into place. That takes just a couple of hours, which is about ten times faster than the classical solution and is logistically a huge benefit for the down-tunnel construction site.
“We have also a project called Edge Computing Underground. That one addresses the digital explosion of recent years. Cities are generating huge amounts of data, and demand for data storage centres, and for places to put those centres, is rocketing. In Singapore, for example, five years from now demand is going to be 80 times greater than at present; in Zurich the figure is a 25-fold increase.
“It seems obvious simply for reasons of space that those centres should go underground but there are other advantages as well. The data must be kept and processed close to their source – a concept called ‘Edge Computing’. A lot of mini and micro data centres are needed to do this.
“Putting them underground gives physical security in age of cyber-attack. It gives proximity to the essential infrastructure that the data relates to, giving quick access and short latency times in an emergency; it gives stable temperature conditions for processing centres that produce a lot of heat, and a very sustainable solution of using groundwater for cooling them. So SCAUT has initiated a concept study and demonstration data centre called Edge Computing Underground.
“It is a joint venture with some of our industry partners Dätwyler IT Infra, Amberg Engineering, Siemens Switzerland and GEOEG. And we are currently operating an underground edge data centre, again in the Hagerbach underground test gallery that we mentioned earlier. It is acting both as a testbed for technical development and analysis and also as an ideal demonstration to present it to interested stakeholders.”
And farming? Surely that, at least, has to have sunlight and open air? Not so: efficient bulbs run on renewable energy can give affordable light; sensors can give precise data to control water, temperature and fertiliser needs; there need be no insect pests or airborne diseases so pesticides can be dispensed with – “and, if your tunnels or caverns are under the city, fresh vegetables, grown in optimum conditions, can be in the shops within hours or minutes of harvesting having used neither time nor energy in transport.”
SCAUT has its own demonstration farm, in another part of that same Hagerbach gallery. Salad crops were successfully grown hydroponically in the ambient temperature and 90% humidity of the gallery, and the first lettuces were harvested, and eaten, last year.
So SCAUT, and Veronika Petschen at its head, in promoting imaginative uses for tunnels may have opened a whole new reason for going underground.
