BLK technology proves itself in one-chance scanning application in Africa

Case study

Accurate BIM scans are essential, but when the source of the data is set for demolition, you don’t get the luxury of a second chance. Right first time is an imperative in these applications. In an interesting twist – compared to the majority of 3D architectural scanning applications – Leica Geosystems hardware and software has been used to create detailed scans of a structure prior to demolition, to create an in-depth environmental-impact report regarding the amount of materials in the building to reduce the waste generated by the deconstruction.

The buildings in question – powerplants – comprised a multitude of different, non-uniform structures, including industrial buildings, service/office buildings and workshops, as well as the actual power station equipment, including all the associated furnaces and pipework.


Scanning, sustainability and safety


The operating company had decided to clean and reuse the sites but needed a cartographic survey undertaken over nearly 20,000 square meters in parallel with the geotagged collection of samples for environmental analysis.

Construction and demolition waste is one of the biggest waste streams globally. With growing population and higher urbanisation, reducing this waste stream is an opportunity. If we are able to recycle the materials from buildings that are not longer needed, we would reduce the need to extract natural resources to make new building materials. This is a key opportunity to preserve natural ecosystems and biodiversity.

Implementing the concept of Circular Economy, the project seeks to reduce the waste generated by recycling as many materials as possible. In addition to a diagnostic report on the quantity of waste created by the deconstruction process, the scanned data and samples also provided the company with the means to identify any potential risks to the health and safety of its employees.

The company responsible for the remote management of the mission and the feasibility study of the deconstruction of the power plants has commissioned the company Accsys Engineering for the on-site missions. Accsys Engineering, a company of 7 employees based in Schiltigheim (Alsace, France), is specialised in building information modelling (BIM), project management, 3D scanning, 3D surveying and studies on special-works projects.

According to David Grandcolas, General Manager of the Accsys Engineering Group: “After the demolition, we would not have a second chance to collect information, once it was gone it was gone! So, the biggest challenge of the project was to create a very accurate representative site survey so that the project could be worked on downstream using only point cloud data to improve material circularity and save costs.”


One chance to get it right



In many scanning applications, any data discrepancies or gaps in the coverage can be remedied by another visit; but in this case, as the site was being levelled, there was only the single opportunity to get the highest quality scan data possible.

“Our scanning jobs are far and wide,” Grandcolas explains. “In a typical application, we would travel to the project site and undertake the majority of scans using the Leica BLK2GO, a handheld imaging laser scanner that creates a point-cloud data for 3D digital twins as you traverse the site. This was ideal for this application as it offers fast scanning of large areas, such as the inside of buildings and, in this case, powerplants.

“When more intimate scans are required – to capture more detail – such as those around the complex geometries of the generators, pipes and framework,” he continues, “we switch to the Leica BLK360, which can scan 360,000 laser setpoints per second and create a 150 MP full-dome spherical image-standard resolution scan generation in just three minutes.”

The biggest opportunity is to reduce the amount of waste, by implementing a smart demolition system where many materials from the construction structure could be reused in a new building or infrastructure project.


Post-processing flexibility



Once the point cloud data has been created, Accsys Engineering exports the data into BLK Data Manager – a companion software utility for the BLK360 imaging scanner. The information is then fed into the BLK Edition of Cyclone Register 360, where it is processed, cleaned and then exported in two point-cloud formats. The final BIM deliverables are 3D models showing the different sampling points and the nomenclatures of the elements and point clouds as LGS files (Leica Geosystems' Universal Digital Reality project file).


Easy to use… and fast

“The BLK2GO is an easy-to-use tool that delivers a good level of point cloud data in a short time,” Grandcolas elaborates. “The ability to track scan progress via the app is very useful as we can ensure that the entire project is scanned, which, as you can imagine, was important in this particular application.

“Overall, it is the speed of the scans that really impresses us,” he concludes. “The portability and the geotagging functions also proved invaluable in this application.”

In most cases, any gaps in coverage can be plugged with a second scan, but when the item you are scanning is being removed, dismantled or demolished, you have to make sure you are right the first time. This BLK hardware and software combination delivers the perfect solution for BIM applications, even when you don’t get a second chance.