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Ship ahoy! It does not always have to be the metro, Vienna has much more to offer. This time we drop anchor at the “Stadtstraße”. The 3.2 km long street is to be built in “Donaustadt” and will connect “Seestadt Aspern” with the highway “Südosttangente”. What is unique about it is that almost half of it is tunnelled underneath, so due to the high groundwater level, a lot of the construction work must take place underwater.

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Engineer and digitalisation expert Sebastian Gerhard from ZÜBLIN Spezialtiefbau and Philipp Eder, who is responsible for the project on behalf of the eguana team, are telling us why anchors are essential for this and how exactly we are supporting the project with SCALES.

Half of the “Stadtsraße” that is to be built runs at a low level and has two tunnel constructions: the “Emmichgasse” tunnel and the “Hausfeldstraße” tunnel. “It is one of the major projects in Vienna,” explains Gerhard. “This means that many trades are busy at the construction site at the same time, and despite the large extension of the construction sites, space – as it is so often the case – is limited.”

The two tunnels are therefore being built using the so-called cut-and-cover construction method: In this civil engineering method, bored pile walls are first constructed. The cover of the tunnel is concreted onto these walls. Then the excavation takes place under the existing cover. This means that the surface of the ground can be driven over again quickly, which is very desirable in the narrow, urban area. “One of the biggest challenges in constructing the tunnels is the high groundwater level. This means that the tunnel structure must be tight and secured against buoyancy. Now here is our part of the game. We build a back-anchored sealing sole. For this, micropiles are first produced that serve as anchors,” says Gerhard.

How does an anchor actually work?

Philipp Eder, an architecture student, knows how to explain complex construction topics simply – and in the case of a grouted anchor, how could that work better than with a regular anchor?

“By prestressing the anchor, the structure is secured against the forces of the ground. In our case, this is the ship that we want to secure with the anchor and the anchor chain – i.e., the tension member.”

The anchor keeps the ship from drifting away (or the construction element from sliding away). This requires traction – but not too much, because otherwise (as can be seen in the second illustration) the ship will be pulled under water (and the construction will collapse).

But if the anchor chain is too long, everything may seem fine at first glance (see figure 3), but with the next current the ship will drift away – and the insufficiently stabilised element will slip away at the first jolt.

Anyone can do “simple”

“The micropiles are then connected to a DSV or underwater concrete slab,” says Gerhard. This is how the soil for the tunnel is created. “The special aspect for us in this process is that we are working under further challenging conditions. The route is crossed twice by the underground and S-Bahn lines. In order to maintain railway operations, two steel auxiliary bridges were installed in advance, under which drilling is only possible at a limited height. This made it necessary to shorten the masts and our equipment had to be specially adapted for this unique operation. Due to the high groundwater, drilling from a work platform supported on rails and from floating pontoons is also necessary.

Water, anchor, what is missing to make the picture complete? Scuba divers, of course!

They were used, for example, to check the overgrowth from the anchor fill, to check the DSV and SOB wall and to install the head plates at the underwater concrete slab.

The vision was poor, said Gerhard, but the water surface looked very inviting at some points when viewed from above – just like in the Caribbean.

Gerhard emphasises: “We worked under enormous time pressure in the track bed of “Wiener Linien” during the track blockage in the summer holidays. Despite the lack of buffer time, we managed to be on schedule!

And there is another complication, because the micropiles must be installed very precisely in the subsoil, Gerhard explains. “This means that the Gewi bar cannot simply be “dropped”, as it is usually the case, but must be lifted into place by using an assembly bar. Since we are post-grouting the anchors, post-grouting hoses must be tied to the anchors in advance. These must not be damaged in order to allow for blasting with water and subsequent post-grouting with cement suspension.”

Maintaining an overview with SCALES

Around 6,000 anchors are needed in total for the project – and six production and injection protocols are created for each pile. It is not easy to keep track of everything.

The focus of eguana is the data management of injections. Since every anchor is related to an injection, it was obvious to also digitalise and visualise the technology and the related data flows. For this purpose, we developed a special input mask for the drillers together with “ZÜBLIN Spezialtiefbau” for the “Stadtstraße” project.

They only need to enter the corresponding data for the nine parameters. Nine parameters, that does not sound like a small number, nor is it – but it is much easier than entering them manually and evaluating them afterwards. Our logging in eguana SCALES then combines all logs fully automatically into one overall log. In this manner, we not only visualise the grouting pressure with which the anchor secures the construction, but also the type of anchor, the drilling depth, the material used and so on.

Through logging, “we are able to obtain the most precise and traceable information about the production of each pile. The digital data obtained originates directly from the device and its operator and can then be evaluated in a very uncomplicated way,” says Gerhard. Every performance is thus precisely documented and traceable, and the potential for errors is minimised.

All easy, one might think. But there were still a few minor teething problems: “At the beginning, there was a problem where the logs were not automatically linked to each other, even though the numbering was obviously entered correctly,” says Gerhard. “After several hours of troubleshooting, it turned out that the letter O (Oscar) looked confusingly similar to the number 0 (zero) and the entry was indeed wrong.”

Dreams of the future

“Hardly anyone else does data management the way we do it,” Philipp Eder is aware. So, the fact that most workers have not yet come into contact with such a form of recording is hardly surprising. “There are logs for the clamping process, but not much else. It would be cool if we could do automatic recording here as well. Then we could really cover the topic in its entirety, from drilling to injection

to the clamping process.” According to Philipp, the only thing that is missing in most cases is the corresponding data logger.

Gerhard foresees the future of anchors in 3D models of the actual installation, including all relevant additional information. In the future, he believes, more machine data will be recorded in general, such as drilling depth recording. This will mean less input from the drilling foreman. An automatic 3D as-built model of the fabricated anchors, which can be further used in the builder’s BIM model, would be another step towards digitalisation.

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About Sebastian Gerhard

Born and raised in the south of Munich, the Züblin engineer came to Vienna back in 2010 to study civil engineering. According to Sebastian Gerhard, his father, also a civil engineer, is not entirely innocent of his fascination with construction sites, which has not failed to captivate him since his earliest childhood.

But he also remains busy apart from the “Stadtstraße”: Swimming, cycling, tinkering with his moped and crafting with 3D printing – plus, the native Bavarian bakes not only pretzels, but also good Italian pizza!

Tunnel construction work is literally a backbreaking job. Especially when it comes to installing stress control elements (weighing 80 kilograms each) overhead. When Manuel Entfellner saw how the workers in the tunnel struggle with this, he decided to do something about it. We spoke with the Implenia site manager about his innovative stress control elements, the lack of error culture and what it takes to move tunnel construction into the 21st century.

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“I am in the tunnel every day whenever I am on a construction site and I’ve seen what a tough job it is for the employees. Installing compression elements overhead is hard work,” says Manuel Entfellner, who works as a site manager in tunnel construction. In the case of difficult geological and geotechnical conditions with a lot of mountain movement, stress control elements are used, which act like a buffer. They “absorb expansions from the rock so that the shotcrete does not crack.” A single element made of regular steel weighs around 80 kilograms. Sweat and back pain are inevitable, the risk of injury is high. Nevertheless, they are indispensable in difficult geological and geotechnical conditions.

Handy, lighter and more stable

There had to be another way. “If I have to lift an element weighing 80 kilos every day, that’s not ergonomically advantageous.” The weight therefore had to be reduced. In a small on-site lab, he began exploring alternative materials and eventually developed block-shaped polystyrene elements to replace the steel behemoths that are common practice. Due to the combination of the new material and the simple shape, the elements are significantly more stable than before, and at only a quarter of the original weight.

Laboratory testing

Installation of the new stess control elements

“Why didn’t I think of that?”

Not everyone was convinced of the success of the project. “There were many critical voices, including within the company,” remembers Entfellner. “Nobody believed that such a light could withstand such heavy loads. An element has to carry 4,000 kilonewton (i.e. over 400 tons). It’s almost impossible to imagine. One thinks that concrete and steel can withstand it, but a ‘plastic’ element?”

At the construction services company Implenia, two people supported his research right from the start: Austria Managing Director Rudolf Knopf and Helmut Wannenmacher, Senior Engineer (and author of our blog post on “Artificial intelligence in tunnel engineering”).

The doubters have now become silent, because the product has proven itself and is already being used. “It makes work easier for the employees, it is a technical achievement and – what I particularly like – it is simply a very simple invention. Everyone grabs their heads and thinks, why didn’t I think of that?”

It is easily explained why no one has thought of this before: “Tunnel construction is a very conservative industry. People often view new ideas very critically. This is not comparable with injections or data management – tunnel construction has been at about the same level for the last thirty years. It may have improved in terms of machine technology, but little has happened in terms of support elements,” says Entfellner.

More openness

According to Entfellner, it takes mainly two things to take tunnel construction forward into the 21st century: new tender- and contract models and a culture in which failures are openly discussed.

“The tendering and contract model that we have in Austria makes it difficult to introduce innovations,” Entfellner wishes for more openness to new models. The problem: The phrasing of the tender for a planned construction is usually phrased extremely specifically. “Even if it might make technical sense, it is very difficult to agree on deviations from that contract. Executing construction companies should be involved as early as possible in order to be able to consider alternative proposals.”

No two tunnels and no two fault zones are exactly the same, and one-size-fits-all solutions are rarely effective. “Each tunnel is unique because the geological conditions are different. More openness is needed in the specialist committees. If you fail at any system – which often happens in tunnel construction in fault zones – then it is kept quiet and hardly ever published. Learning from mistakes doesn’t work that way, everyone starts over and repeats the same mistakes that have already been made on other construction sites or in other parts of the world.” Everyone likes to talk about success, Entfellner knows – but what we should talk about is failures.

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About Manuel Entfellner:

“Rock is my thing,” says Manuel Entfellner about himself. From an early age, the enthusiastic climber, mountaineer and amateur geologist knew that professionally, things would go in the direction of construction. After graduating from the HTL Bautechnik Salzburg, he initially did a bachelor’s degree in “civil engineering and industrial engineering” and then specialized in tunnel construction in the master’s degree.

Winter water is coming. In our industry, this is usually not a reason to be happy, but when it comes to diaphragm walls, water (in combination with bentonite) is absolutely necessary. To ensure that there is always enough fluid inside the diaphragm wall to stabilize it, it needs a guard who sounds the alarm when the wildlings are approaching the level drops below a critical level: eguana CROW.

Like Jon Snow, Lord Commander of the Night’s Watch and Warden of the North, CROW is always on top of things. The innovative, electronic diaphragm wall monitor has been in use on the construction site since april 2021. It is easily attached above the diaphragm wall and automatically measures the water level. We talked to foreman Walter Ortner from PORR AG and eguana software engineer Joachim Ofner about the necessity, function and the first flight attempts of our CROW.

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Hello Walter, hello Joachim! Thank you for taking the time to answer a few questions about CROW. What is a diaphragm wall and why do you need someone or something to guard it?

Joachim: By definition, a diaphragm wall is “a protective wall that is manufactured in sections in a floor slot”. During manufacture, the space between is filled with a support fluid to ensure soil excavation and thus prevent a collapse.

Walter: It’s normal for some of the support fluid to seep into the ground. Before it falls below a critical level at which the support capacity is no longer given, the fluid needs to be “refilled”. It is therefore important to continuously monitor the level of support fluid in diaphragm walls.

To illustrate the importance a bit, diaphragm walls are also used to support neighboring buildings when one building is erected very close to another. If the supporting liquid in the slot sinks too far during the construction and the support is no longer given so that the slot collapses, this can have a very negative effect on the statics of the neighboring building. In this case, the situation is probably so critical from an insurance point of view that the construction manager will personally stay overnight on the construction site until the problem is solved. But in such a case, one would certainly like to have an electronic diaphragm wall monitor that sends alarms before critical levels have been reached …

How have the water levels been checked so far? What is the alternative to CROW?

Joachim: Until now, diaphragm wall guards have been actual people who drive to the construction site to check the level of the support fluid there. Or very complex and error-prone constructions that have to be positioned over the slot using a crane. Of course it’s all about the time when nobody else would be there, for example at night and on weekends. This is expensive and checkups cannot happen every 10 minutes. Our CROW on the other hand loves to that (and also all weekend long).

And what exactly is CROW doing?

Joachim: Basically, it measures a distance of up to four meters from objects with an accuracy of about 1 centimeter. The sensor emits light that hits an object and then measures the time it takes for the light reflected back to the sensor. By attaching it over a diaphragm wall, the current level of the supporting liquid can be measured – almost like Superman’s laser eyes. But I don’t know if Superman ever used them to measure distances…

CROW is a sensor of our data logger MERLIN. That is, MERLIN can measure distances through CROW. He then sends these to eguana SCALES. The data is logged and, like all other data, is available on the platform at all times. By constantly logging the level, it is possible to estimate when the support liquid needs to be refilled. In addition, alarms can be sent to the people responsible, who can then react faster and better.

What gave the impetus for its development?

Joachim: Our partners from PORR initiated the topic with us. It’s expensive for a contractor to keep having someone on site over the weekend just to check the level. Stefan Fuchs [note: the PORR project manager spoke to us a while ago about TempJet, a system for determining the diameter and cement content of jet grout columns] and Walter Ortner were the driving forces without which our CROW would probably not have learned to fly.

Did you know from the beginning how the end product should work?

Joachim: During the early stages we considered installing a camera at the diaphragm wall to be able to check on the level from a distance. However, this is more expensive than measuring a distance directly: you would also have to attach something like a yardstick to the diaphragm wall for the observer to know the water level. And it would also bring other problems with it: Surveillance cameras on the construction site would have to be approved. Would we have to make people seen on the footage unrecognizable for data protection reasons?

Where and since when is Crow successfully in use?

Joachim: After a rework in autumn last year, the new version has been used on a construction site in Vienna since February 2022.

First, Crow was set up in addition to normal operation as a test. In the meantime, however, trust in the device has increased. Now Crow is in constant use and is already making itself really useful.

As a customer, can I choose the color?

Joachim: That would be possible in principle. But there hasn’t been an inquiry about it yet, presumably because after a while it’s speckled in the uniform concrete slack gray of a construction site anyway.

How robust is CROW? I’m thinking of MERLIN, which easily survives getting run over by a car.

Joachim: It’s still in the prototype stage, which means it’s currently in a 3D-printed plastic housing. The functionality is already there, but we want to make it even more robust in the future, and the lens still has to be better protected against dirt and scratches. That is why we are going to protect it with an aluminum housing, just like MERLIN.

CROW can be used in many ways

Pablo uses it to keep an eye on the water level in his pool.

CROW is a sensor of the data logger MERLIN

MERLIN (the gray box) measures distances through CROW (the green box) and sends them to eguana SCALES.

Paper bottlenecks can be avoided …

… coffee bean stocks can be monitored …

… and toilet emergencies can be prevented.

You mentioned a rework last fall. Did everything go according to plan during development? I remember that Florian was about to throw the little guy out the window several times with an unnerved “Fly, little CROW!”.

Joachim: It really wasn’t easy and we wanted to give up more than once. The last hardware version worked wonderfully in the laboratory, but as soon as we tested it on the construction site, the measurements were partially unusable, without a reason that we could identify.

So we tried to simulate the environmental conditions of a construction site. Flo had the sensor measure the water level in his rain barrel in his garden at home. But what worked day and night, in sun and rain, suddenly no longer worked on the construction site. That’s how a NASA engineer must feel, trying to debug a rover on Mars only with data that is sent to Earth and an identical rover in the laboratory, where Martian conditions are simulated…

Sounds like that almost put an end to Project CROW?

Joachim: That’s right. Quite unnerved, we started one last attempt last autumn and tested some sensors of a similar kind for their suitability as diaphragm wall monitors. One of those sensors did what we wanted it to do! But construction sites are tough and we’re excited to see what challenges the little CROW will have to face in the future.

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We have had good experiences with kitchen comparisons in the past, so today we again approach a topic of foundation engineering from the edible side: namely a research project called AVANT, which deals with the use of artificial intelligence in grouting processes.

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If you look at the use of construction site data, as is currently the case on many special foundation engineering projects, you can compare it to the production of a mug cake. Solid basic principle, good result – but nothing special and unfortunately extremely error-prone.

Because if the cup size is not correct, everything gets mixed up – similar to construction sites that are not sufficiently digitized, where the data format of the drilling rig is not compatible with that of the pump and ultimately a manually maintained Excel file is used. It is a mediocre solution that is difficult to transfer to other construction sites.

Things are completely different when using eguana SCALES. To convert it to our dessert version: Scales is like using kitchen scales for preparing our mug cake. Instead of manual or semi-manual reports, with SCALES the device data is transferred directly, standardized and digitally – i.e. the ingredients are practically weighed to the gram – and automatically evaluated, analyzed and graphically processed.

And what more could one want than a perfectly weighed and precisely prepared bakery product?

But what use is the most perfect recipe if you don’t know if your guests will like it? Or to put it another way: What is the point of preparing the data afterwards, if the respective process has already been completed at the time of the analysis?

AI improves injection processes

I want to know if my guests are allergic to nuts or do not like raisins BEFORE I stir the ingredient into the batter. And this is exactly where our AVANT research project comes in. We spoke to project engineer and researcher Christoph Klaproth about it.

“The AVANT project wants to improve the processes in the grouting area,” says the STUVA expert. “The construction sector is getting more and more digital. In other words: We have tons of data and this data is simply not being used in the way it could be used. That’s why we launched the AVANT project, to evaluate this data even more than it is today, and also to evaluate the whole thing automatically in order to ultimately improve the grouting process.”

In the course of the project, data that is produced during grouting is to be automatically evaluated during operation. The aim is to train an artificial intelligence in such a way that it can make forecasts after individual grouting rounds and make suggestions regarding grouting planning and further tunneling. (To stick with our cake metaphor, the AI remembers if there were too many raisins in the batter the last time you tried the recipe, and automatically adjusts the amount for the next time)

The name AVANT stands for ‚Adaptive Planung von Injektionsmaßnahmen im Tunnelbau mittels Künstlicher Intelligenz‘ [eng.: ‘Adaptive planning of groutinh measures in tunnel construction using artificial intelligence’]. It is an association of Austrian and German research institutions and companies with the aim of promoting the digitization of the industry

Exciting home stretch

The project started in 2020 and is scheduled for three years. So far, a massive database has already been viewed, sorted and evaluated in order to be able to continue working with it. One could say that the dry preliminary work is complete.

“Things are going to be exciting. We have already made initial attempts with AI algorithms. Of course, we also encountered a few problems resulting from the fact that the data recording is still not very coordinated.

Data is recorded, but of course it is not yet standardized how it should be recorded. This affects the naming of the data, the assignments and the like. It is not yet established in everyday construction site work that the data is recorded and named in a standardized way so that it can be assigned afterwards so that conclusions can then be drawn. It starts with the nomenclature, in other words: the designation of the data sets is not consistent, some data is missing and the individual processes were carried out differently without us having any information about why that happened – were there delays in the construction process, were there any difficulties setting up and dismantling the grouting?” Klaproth lists problem areas.

As a result, this very different data had to be sorted and put together like pieces of a jigsaw puzzle. The extent of the work required is greater than previously assumed.

The project participants

The construction data that is fed to the AI is provided by STRABAG and Züblin Spezialtiefbau, which as a construction company has access to large amounts of data. AVANT uses two types of data: On the one hand, the MWD data (measurement while drilling). “These provide information about what the borehole ultimately looks like,” explains Klaproth. From MDW data you can “get insight as to whether there are chasms in the mountains and the like.” The Montanuniversität Leoben, as another research partner on the Austrian side of the consortium, is mainly responsible for the analysis of these drilling data.

On the other hand is “the pure grouting data that represents the grouting processes. So the pressure that is applied and the flow rate that is introduced into the rock.

The German project partners are Geoteam Dortmund, which provides support for questions relating to the geology of the mountains, and STUVA, which is primarily responsible for artificial intelligence.

As a link, eguana takes care of the data preparation and acts as an interface to the construction site.

Possible goal of the project could be either a program that can be downloaded by the site manager or a box that can be connected to the machines.

Time to stop

While we have to keep an eye on our cake during the baking process and regularly check that nothing is burning anyway, the AI in AVANT should learn from build data to determine when it is a sensible time to stop the injection. “She learns when certain characteristics occur,” says Klaproth. Together with the client experts on site are currently deciding on the basis of various termination criteria whether grouting was successful or not. “To be on the safe side, people usually inject more than they may need,” he says. “We want to automatically transfer these termination criteria so that we can then automatically recognize them at an earlier stage.”

Just like our AI we know when it is time to call it quits. We would now like to declare that the termination criterion for today on the subject of AI has been met.

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A big thank you goes to our guest author Christoph Klaproth, who not only contributet a lot of technical understanding, but also a lot of patience for questions 😉

A user interface that clearly displays a construction site in all its facets? Fast documentation, comprehensible reports and clean formatting? Sounds like eguana SCALES – but it’s not. The software of recordIT is the visual counterpart to our data management tool and enables a construction site to be displayed in visual form. The range is now to be expanded to include a tool that can be used to record and display buildings in three dimensions.

We spoke to founder Stefan Grubinger about his virtual baby, the hurdles of a start-up and innovation-resistant civil engineers.

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Since 2018 the state of Salzburg has had around 5,000 supporting structures near state roads surveyed. The project duration is five to eight years, the survey is carried out by external engineering offices – a long duration and many different project participants working with different systems and structures, and consequently also a lot of potential for discrepancies and errors. What sounds difficult is made easy by the software of record IT. The documentation is based on precisely defined templates and all buildings are recorded in a standardized way.

The survey from the state of Salzburg is just one of many applications for the digital tool. For the new construction project “S7 Fürstenfelder Schnellstraße” the app enables ongoing documentation of the construction progress as well as the recording and management of defects. The photos taken are recorded both on a digital plan and in the Geographical information system assigned to the recording location and are therefore easy to find.

Everything in view, right from the start

The idea for the tool arose – as it is so often the case – out of necessity. When writing and formatting reports, the shoe often pinched. “In the course of construction sites and the reports to be created, I was looking for a solution that would enable me to create user-adapted reports directly on the tablet. Since I hadn’t really found anything that appealed, the idea of developing something myself or having it developed soon came up.”

The founding team also includes civil engineer Matthias Rebhan from Graz University of Technology (LINK to blog post); web developer Simon Jiménez; and Roman Marte, university professor and head of the Institute for Soil Mechanics, Foundation Engineering and Computational Geotechnics at Graz University of Technology. The team has now grown to ten employees. “Computers should do what computers are good at, and people should do what people are good at,” Grubinger summarizes the idea behind it. “Furthermore, when writing reports, the frustration factor should be pushed into the background and the content should be given more time and attention.”

Photos, maps and information can be easily created on site and individually adapted to the respective situation. This can be entire texts or individual keywords, or predefined queries. The maps allow screenshots to be taken directly from the software, and different layers such as conduits, roads or rails can also be imported. Reports on this can also be adapted to the relevant requirements and automatically generated and evaluated. These evaluations and investigations are currently still being carried out by human users, but work is already being done on artificial intelligence to automate these activities.

The name recordIT is ambiguous in an unambiguois way and appropriate in every respect – photos, sketches, map sections, etc. can simply be taken on a tablet or mobile phone and the information can then be called up in the form required.

recordIT, founded in 2017, is now used in various areas, from security checks of buildings to the documentation of construction progress on underground routes. For example when inspecting torrents, where grievances such as fallen trees, mudflows, etc., are recorded, located and automatically processed. By locating these data in properties and linking to land register data, notifications to property owners are automatically generated and sent, and reports for communities and statistics are generated.

The software is therefore not only suitable for everyone who carries out documentation services on and around construction, but also for users in non-industry areas.

Inspect 3D – a three dimensional construction site

The survey can be conducted during the entire service life of the structure, starting with the inventory through the actual construction phase to the control and testing during the operational phase. According to Grubinger, a lot is currently being invested in this area in particular.

For this reason, the company is now taking things even further: In cooperation with the company Robotic Eyes, Grubinger’s team developed the inspection tool “Inspect 3D” – and this enables the user to display a building in all its development phases in three-dimensional form. A digital twin in 3D that displays photos, images of defects and other anchored information in augmented reality, as if you were actually there.

The tool is “precisely tailored to the requirements of tests and inspections” and allows “a 3D view of the structures in addition to the creation of reports. That way, photos and information are linked directly to the building and can be called up there again later – it is almost impossible to mix up photos and information.”

Don’t give up

However, getting started as a start-up wasn’t always easy, Grubinger recalls. “Especially in the initial phase, where a few euros would go a long way, it is very difficult to get financing. It’s a vicious circle.” In order to receive funding, you have to be able to show a product – but in order to be able to develop a product, you need financial resources.

And although the desire for better digital tools is growing louder and is also increasingly being demanded by employers, “many civil engineers are still unaware of this”, says Grubinger. Nevertheless, the demands for it are getting louder and the industry, triggered by the requirements of BIM, is slowly being shaken up and inhibitions about new technologies are increasingly being broken down.

recordIT’s innovative software is not immediately accepted everywhere. “A civil engineer once told an employee that he had no need for the software as he had the most efficient way of working anyway: He said that instead of documenting it himself, he calls his secretary and then explains everything to her and she writes it down. I actually had to grab my head in amazement.” In principle, however, not only the need but also the desire for the software is great, says Grubinger. By using the app to create reports, lists and checklists in no time at all, not only civil engineers but also all people who have to carry out regular checks and inspections of buildings of all kinds can work more effectively.

“What we have learned is that you have to continuously work on your idea and that there are always situations that set you back. But many a night shift has been useful and under such pressure one or the other very good idea is born that not only helps in this situation. Regularly rethinking the current situation and, if necessary, realigning individual points or even the company can help to make many things easier and also provide great added value for the customer!”

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About Stefan Grubinger

Documentation without frustration – it must be possible! Thanks to his many years of experience in the construction industry (he was born in Salzburg and worked for years as a construction engineer while studying industrial engineering at the Technical University of Graz before he set up his own business with recordIT in 2017), Stefan Grubinger knew exactly where the shoe pinched. That is why, together with a few colleagues, he set about solving the problem and simplifying the documentation of construction processes. Although the master builder now spends a lot of time in the office, he prefers to be on the construction site himself.

Micropiles and giant excavators, Matthias J. Rebhan’s work includes everything from small devices to large machines. University research is conducted in dusty libraries, the scientists in their ivory towers are paler than Count Dracula from all the indoor work? Not at the Institute for Soil Mechanics, Foundation Engineering and Computational Geotechnics (IBG for short) at Graz University of Technology. The civil engineer and laboratory manager Rebhan talked to us about exciting projects, cool machines and the future of civil engineering.

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The employees at the IBG deal with “a wide range of geotechnical and structural issues related to geotechnics, foundation engineering and numerical geotechnics,” says Rebhan. Founded in 1964 by Christian Veder, the father of diaphragm wall technology, the institute was expanded in 1997 to include numerical geotechnics and now has 25 employees. “We work and do research on just about anything – which, among other things, is due to the possibilities of the university, but is certainly largely due to the interest of our institute director, Roman Marte.”

There is, for example, a dynamic test cylinder for micropiles under tension…

… or a new concept for recording the prestressing force in strand anchors:

Diverse portfolio

Giant trucks and micropiles can also be seen on Rebhan’s LinkedIn profile.

“Projects are currently running on anchor technology and the reliability of geotechnical structures, the monitoring of structures, the determination of subsoil parameters and the derivation and mapping of subsoil models, but also projects that go into the area of numerical simulation of construction and investigation methods.” In cooperation with the Institute for Manufacturing Technology they are currently developing a test device for micropiles for the introduction of tensile loads into the subsoil – this can be used in rockfall protection nets, for bank protection or the foundation of noise protection walls. “This project is currently a very instructive (albeit sometimes strenuous) activity, because on the one hand the ideas of civil engineers and mechanical engineers differ widely and on the other hand because we have found really new and innovative solutions here that will certainly accompany and challenge us for some time to come.”

There are also micropile and anchor tests, laboratory tests to determine subsoil parameters and expert opinions in the event of damage or problems.

Beyond institute boundaries

One project investigates the possibility of impulse testing of micropiles. Everyone involved in the project agreed that there must be a way to simulate such a load – but how? “We had the idea of applying the impulse via prestressed springs – but the energy density here is far too low.” The current solution consists of a prestressed hydraulic cylinder.

The solution (in the form of a prestressed hydraulic cylinder ) ultimately came from the Institute for Manufacturing Engineering – for Rebhan clear proof that the implementation of such projects at a university is of great added value because one can draw on expert knowledge from a wide variety of departments.

Because “every test – whether in the laboratory or in the field – usually requires an adapted test device or special equipment. The exciting point here is finding the right device for the task.” In the institute’s ‘vehicle fleet’ you quickly reach your limits, which is why you have to look for solutions elsewhere – and that is exactly one of the points that makes his work so attractive, says Rebhan. Creativity and a look beyond ones own institute’s boundaries is often required – what you are looking for can often be found in other disciplines, departments or institutions “like in one of the last projects with the fire brigade. This is also the reason why the work in the laboratory and experimental technology is so exciting and why the work at the university is so fulfilling that I wouldn’t trade it for anything else.”

This year, in order to complete two anchor technology projects a few last series of tests with new testing facilities still need to be done. In addition, field tests are pending “where we want to examine a special probe for measuring the soil pressure, for example, want to look at the properties of a thermally improved concrete for diaphragm walls, or where we want to test the load limits for ductile piles or micropiles made of wood.”

Expect the unexpected

Things rarely work out as expected. “Fortunately, nothing has gone monumentally wrong so far. Of course, some trials didn’t go as expected, but so far we’ve always managed to get the results we wanted – even if they weren’t what we expected. 😉”

For example it can sometimes happen that a micropile has to be subjected to computer tomography – much to the delight of the radiology assistants, Rebhan recalls: “It was their first patient who didn’t move during the imaging and wasn’t in pain.”

Another time, employees of the ASFiNAG route service expressed concern. They believed that the builders could destroy structures with their laser devices – a legitimate concern.

Outdated university research, conducted in dusty libraries? “A former professor at Graz University of Technology once said that “a good theory is very practical” – and I think that is exactly what describes the work at our institute very well.” Of course, even the most practical projects need a theoretical basis, but “fortunately we are not gathering dust during our work – because it has been shown that in large and small experiments, the child in all employees at the institute very quickly comes to light.”

Sustainable and innovative? Not exactly

Sustainability is a key issue that is particularly important to Rebhan. According to Rebhan, there is still a lot of room for improvement in the construction industry in this area. “A major focus in research must be sustainability, the conservation and saving of resources. We have a lot of catching up to do in the field of geotechnics – both in terms of construction methods and the use of building materials.”

However, interest in innovations and further development is there. The fact that the industry is still miles behind when it comes to digitization, for example, is not only due to the industry itself, “but also due to the fact that every project in the construction industry – whether it’s a single-family house or the construction of a new subway line – represents a special solution and therefore can only be compared with other projects to a limited extent.” Each problem is currently considered on its own, each problem solved individually – innovation is therefore only effective in individual cases and does not go beyond the construction site. Therefore there are hardly any learning effects.

Nonetheless: The potential for major innovations to advance the entire industry does exist, says Rebhan. “Innovation can be done in every area – materials, construction methods and digitization. However, I believe that sustainability and resource conservation (and not profit) must play a part in all innovations.”

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About Matthias Rebhan

Rebhan’s career in the construction industry started in the sandbox. “According to my mother, it was nearly impossible to get me out of the sandpit or take the Lego bricks away from me.” After graduating from high school, Rebhan actually wanted to stay in structural engineering. It was an exciting lecture of Roman Marte, board of directors of the IBG, that sparked his interest in geotechnics. What fascinates him is the wide range of tasks and the overlap with other areas of construction. Rebhan has been a technical employee at TU Graz since 2016 and a senior scientist and laboratory manager since 2021.

Credit: Rebhan/TU Graz