Digital Tools in Road Construction

STRABAG is successfully using BIM2Field in road construction to construct the bypass in the Czech town of Brandýs. Model-based planning and the processing of drone and satellite data enable machine control via GPS and to visualise the completed and upcoming work in augmented reality.

Just under 35 kilometres outside the Czech capital Prague, Martin Kriz, BIM expert at STRABAG Innovation & Digitalisation (SID) in Vienna, and site manager Jiří Cingroš are standing on an filled-up dam. STRABAG is building a bypass here: four kilometres long, plus two roundabouts – and the team led by Jiří Cingroš and Martin Kriz is successfully using BIM2Field in road construction.

Jiří Cingroš installed the device in the middle of the dam on a simple mount and linked it to a precise GPS location, and now it shows fascinating pictures – as if someone were drawing the future in bright colours, 3D models of the road yet to be built emerge. It nestles directly into the natural landscape as visualised augmented reality (AR). “I can aim at a point in the surroundings and the software shows whether the roadway still runs there, what work is being done at this point, whether pipes or cables are lying dormant underground – all digitally“, explains the site manager.

Site Manager Jiří Cingroš sets up satellite-based localisation with his smartphone.

In Brandýs, BIM2Field has arrived in road construction. The BIM strategy for the use and transfer of information from the planning to the execution phase, combined with an update of the models after construction, works in a special way in this project, as Martin Kriz explains: “Visualisation via augmented reality is one of the most exciting innovations in the application. It serves as an additional control tool, but above all, it makes BIM really attractive for everyone who uses it.“

Defining standards

The information and data behind it are at least as attractive. “Uniformly and stringently recorded, collected and stored, they are available to the entire project team anytime and anywhere via a cloud-based shared data environment“, says Kriz.

On the construction site, all digital tools interlock: the 3D models, GPS positioning, and drone and machine data. All information is extracted directly from the BIM model and made digitally available to the foreman. In the application, it is possible to switch between a smartphone-based augmented reality and the depiction of the real environment: between the real, somewhat drab dam made of wet sand and the virtual road, along with dimensions and a colourful depiction of the various subsoil layers.

Digital machine control – data from the BIM models, drone imagery, AR and satellite-based positioning all end up in the cockpits of the construction machines.

For Jiří Cingroš, who uses these tools every day in practice, GPS positioning is indeed a great advantage. “My AR device has a powerful GPS antenna“, he says. “With it, I can make simple measurements and compare models with reality.“ For these analyses, he would normally have needed a surveyor. But now, Cingroš can evaluate most things himself with just a few taps of his finger. The monthly drone flights are also very useful for the site manager. “We can visualise the construction progress on the basis of these images. And we can use the inventory records for billing and performance reporting.“

This can be used, for example, to automatically control and calibrate bulldozers on the construction site.

Proof of Concept

In Brandys, these data end up directly with those responsible on the construction site. “It’s not only the BIM programmers who work with it but also us construction people“, says Jiří Cingroš. He considers machine control to be the most important feature in his work: excavators or bulldozers also receive data and can be controlled in this way. “We work much faster, much more effectively this way. Another advantage is the AR application, with which we can directly check the accuracy of the models. We also no longer have to validate the machine calibration every hour. And, of course, we also share all documents digitally in our internal Common Data Environment system“, says Cingroš. This cloud-based environment for creating graphical elements works “based on Trimble Connect, MS Teams with Sharepoint background, as well as digital signatures with Adobe Sign“, Karel Vonka notes. He smiles, adding, “Ultimately, we are looking for proof of concept, proof that BIM2Field works in road construction.“

Precise localisation – with modern GNSS antennas, mobile devices such as smartphones can be localised via satellite on the construction site and provide reliable location and time information. By combining AR and BIM models, work that has already been carried out along with work that is still to be done is visualised, and blended directly into the natural environment.

“All construction stakeholders must speak the same language”

Karel Vonka

Technical Operations Manager BIM and Digitalisation for the division Transport Infrastructure and Building Construction Czech Republic/Transport Infrastructure Slovakia (UB60)