Drones in Construction Safety and Risk Mitigation

Drones and Pre-Construction Inspections

One of the most important phases in which drones help to mitigate safety risks on construction sites is the pre-construction phase. Previously surveyors would have needed to physically walk the site before a project could begin, however, this can be extremely dangerous as construction sites can often be challenging to access and even unstable at times.

At Gilbane, our Virtual Design and Construction (VDC) departments conduct drone flights as a valuable risk mitigation measure for our project teams.  As the drone hovers over a construction site, it automatically captures images at regular intervals meaning that one drone can capture photographs of an area of 10 acres in approximately 20 minutes.  The photographs are then used to create 3D point-cloud and orthographic images used to verify foundation layouts, anchor bolt locations, and plumbing and electrical stub-up locations. Images taken from the drone are processed through Pix4D photogrammetry software.  This program compares the photos of objects at various perspectives to calculate their 3D geometry.

Access to these 3D maps means that we have a better upfront understanding of what hazards may lie on the site grounds before we have to send in our workers. Although these images do not replace licensed survey verification of as-built conditions, they serve as a useful check for any gross misplacement of foundation elements or underground utilities.  This is an invaluable risk mitigation measure; the earlier mistakes are realized, the less costly they are to correct.

For example, our VDC team in Connecticut conducted a drone flight to verify existing exterior wall and window conditions for a 15-story high-rise building renovation located on a bustling, occupied school campus.  Due to the height of the building and the proximity of neighboring structures, the only way to perform this visual inspection was from the air.  The size of the drone (roughly one cubic foot) allowed it to maneuver with ease between the closely spaced buildings.  Had we not utilized drone technology, the alternative, and traditional, method would have been for our project team to employ a system in similarity to window-washing scaffolding.  This would have not only been costly for a building this size, but also an extreme safety risk.  The drone allowed us to confirm the conditions of the exterior masonry, windows and louvers, and carry the appropriate renovation budget for our client.

Drones and Real-time Construction Site Monitoring 

Another challenge that companies often face is the monitoring of a large construction site. Whether it be security surveillance or overall progress reports, the real-time video footage of a site’s condition that a drone can provide means that these tasks can be completed more efficiently, and more safely than with personnel on the ground.

This can also be applied to planned and reactive maintenance inspections. It should come as no surprise that tall structures such as bridges and towers pose large risk potential when it comes to construction personnel. This risk is mitigated with the use of drone technology as inspectors can now carry out remote inspections on these types of structures. With the use of thermal imaging cameras, many drones are able to detect leaks and even cracks in the structures or foundations which in turn offers us the ability to maintain facilities proactively.

Drones provide extra information that we wouldn’t have otherwise, which helps to keep our construction personnel out of harm’s way. Learn more about what it’s like to build with Gilbane Building Company.

This blog was updated November 2021.