Preserving historic architecture in Brussels with Monitoring Solutions

Heritage structures are imbued with culture, architecture, and history – they tell stories of our past, enrich our present, and bring continuity into the future. However, preserving these structures amid modern construction efforts, such as building the new Toots Thielemans subway station in Brussels, often presents challenges. To ensure preservation amid progress, the joint venture S.M. Toots (BESIX, Jan De Nul, Franki Construct), deployed Leica Geosystems Monitoring Solutions to protect the 19th-century South Palace, a historic structure in the area of construction, with real-time data about movements and structural stability.

Join Jens Muylaert, a survey engineer at Jan De Nul, as he navigates the historic preservation of South Palace amidst the construction of Brussels' new subway. Discover how the Leica Geosystems' Monitoring Solutions are redefining the field of architectural conservation.

Jan De Nul: global experts in construction and surveying

Jan De Nul is a global contractor acclaimed for prominent projects like constructing Palm Island in Dubai, creating a new mangrove habitat in Ecuador, and expanding the Suez Canal in Egypt. They specialise in a range of areas, from dredging solutions and offshore energy to construction projects and environmental activities.

Drawing from their expertise in infrastructure and building construction, Jan De Nul joined with Besix and Franki Construct to construct the new Toots Thielemans subway station in Brussels, part of a larger project to increase capacity by connecting the city’s North and South lines. Working with MIVB Stib, the public transportation company of Brussels, the project became more than just an infrastructure upgrade— it was a meeting point of modern engineering and historic preservation.

Monitoring structural stability amidst construction

Monitoring became crucial when the project encountered a significant historic building – the South Palace. The ornate and eclectic architecture of the South Palace, built in the 1800s, has long defined the structural landscape of Stalingrad Avenue. However, located above one of the planned tunnels and against the backdrop of changing site conditions, the initial design had to be altered, leading the team to dismantle the interior while preserving the exterior facades.

As part of their efforts to conserve the façade, Jan De Nul used advanced Leica Geosystems Monitoring Solutions.

“Monitoring plays a key role in preserving the building’s historic and architectural value and stability,” says Jens Muylaert, a survey engineer working on the project. “We monitor the facades and will continue as work progresses in the future.”

The monitoring setup: sensors and software

Consulting with the local Leica Geosystems team, they efficiently set up the entire system to monitor interior and external structural components for movements. Leica robotic total stations installed atop large pillars or fixed on facades provided a wide field of view. Connected to and configured with GeoMoS monitoring software, the total stations automatically measured to prisms, detecting the correct prism even in areas where they were densely positioned due to enhanced targeting quality in Leica monitoring total stations.

Measurements were collected by GeoMoS for analysis, reporting, and, when necessary, alerting stakeholders if set tolerances were exceeded. GeoMoS also enabled the team to check on the site from the office using remote imaging.

“We can easily take over in GeoMoS Monitor where you can look through the camera itself, so it’s like you are up there, sitting on the façade and checking if something is wrong,” explains Muylaert.

Surveying work on-site streamlined with one supplier

In addition to monitoring the site, Jens Muylaert applies other Leica Geosystems sensors and software for surveys and as-built checks, including the Leica MS60 MultiStation, the RTC360 laser scanner, and the GS18T GNSS smart antenna.

“Having one supplier for all the equipment is very useful because you can easily export data from one instrument to the other, or to the software,” says Muylaert. “We do a lot of scanning and topographic measurements, and we can combine it into one software program like [Leica Cyclone] 3DR.”

Conclusion

With this project, S.M. Toots and Jan De Nul not only showcase their commitment to using modern technology to protect historic architecture but also underscores the crucial role of advanced monitoring solutions in such endeavours. The firm's work on the North-South Line and the Toots Thielemans subway station in Brussels will serve as a case study for similar future projects worldwide.

“The monitoring data enabled us to protect a very important heritage building," summarises Muylaert, highlighting the critical role of real-time data in preserving architectural and historical integrity while facilitating progress.