Eye in the sky

To help track project progress and identify build errors on a compact city project, construction firm VolkerWessels used crane mounted reality capture to get high-quality data every day

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Building residential properties is never an easy task. And if the jobsite is located in a tight downtown space, the project can become even more challenging, and every mistake very costly.

In 2018, VolkerWessels, a well-established Dutch construction company, was commissioned to build a hotel for the WestCord hotel chain, located in the city centre of Groningen, the Netherlands.

The building consists of 123 rooms, spread over six floors, as well as a 1,000m² catering area, located on the Grote Markt. Since Groningen is prone to earthquakes, one of the requirements for the hotel is that it is earthquake proof.

No room for errors The site is located in the city’s busiest area, leaving no space for storing or assembling materials on site. As a result, VolkerWessels’ team counts on prefabricated modules.

While prefabrication saves time and space on site, it requires precision scheduling and planning of deliveries.

“Once delivered, the prefabricated elements have to be installed immediately. Every minute delay can cause truck traffic and we want to avoid it,” explains Arnold Pit, BIM process manager at VolkerWessels. “The most challenging part of the project is that everything must fit at once - there is no place for deviations. We use prefabricated modules, and if there is a mistake, it would cost us a lot of effort and time to re-make the elements.”

Avoiding congestion The central location of the project imposes careful logistics planning on VolkerWessels’ team. There is a strict schedule for assembling prefabricated modules and deliveries since “every deviation would cause delay in logistics, and sequentially in the project,” says Pit.

The team has to schedule the deliveries every morning to avoid causing truck traffic from material and equipment 1 Rendering of the finished meets earthquake regulasuppliers in the afternoon. “We hotel on Grote Markt tions, while the MVP subare tight to specific times to 2 Assembling precast contractor checks installadeliver our materials. Due to concrete on site tions, such as ventilation and regulations, we cannot be a reason for traffic,” comments Pit. 2 Superintendent looking at the data in Pix4Dbim Cloud electricity. The benefits to the project There are two other construction sites next have been significant. As part of the to the VolkerWessels’ site, so delivery times superintendent’s daily checks of as-built have to be coordinated with them as well. vs as-designed, it was noticed that the floor formwork was not in the right place, Staying on track deviating by 35cm. “I cannot imagine To avoid any schedule deviations and how we could have discovered this error logistics problems, the team has to be so early without this tool,” said Pit. aware of the daily progress of the project. Spotting misplaced formwork is critical Since drones were impossible to fly down- as formwork affects the structural perfortown, Groningen, the team decided to use mance of concrete. “If the error was not a Crane Camera solution from Pix4D, a spotted in time, the worst-case scenario technology the company had previously would be to pour the concrete for the used on a pilot project in Eindhoven. floors and discover that the structure is

The solution consists of a number of con- unbalanced. This could be very dangerous nected camera systems mounted on tower and result in building failure. This would crane jibs, which capture images automati- have irreversible consequences,” says Pit. cally as the crane moves. Images are then “Another possibility would be to discovwirelessly sent to the cloud where they are er that there is not enough support for the automatically processed and transformed elements on the floor while laying the coninto 2D maps and 3D models. crete on the formwork. In this case the

Project data delivered from the Crane team would have to uninstall all these eleCamera solution is used by several differ- ments and re-make them. This would ent team members and stakeholders. The delay the project and lead to increased superintendent checks the formwork and costs and extra efforts.” the floor steel to plan the daily work and With the help of the Crane Camera soluthe logistics. The project manager uses it tion, the VolkerWessels’ team has avoided for visualisation to communicate project potential delays and costly rework. They progress to the client, importing point also continue to keep track of the project clouds to Trimble Connect. and solve the logistic and planning chal-

The earthquake specialist checks the lenges of the downtown hotel project. installations and makes sure the building ■ pix4d.com

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