Collapse Feature Inspection & Survey

Midlothian, Scotland

Flight Goals:

• Survey the collapse feature and the surrounding area using a volumetric flight plan
• Gather high quality inspection video from within the collapse feature
• Calculate the volume of the collapse feature
• Provide topographic information for the area surrounding the collapse feature

Key elements of project:

• Fly within and around a recently formed hole of unknown size and status
• Use a drone to record the conditions within the hole
• Gather data to help the client determine the cause

UAV 365 were called to a site to investigate a newly formed hole of unknown size and state. A risk assessment carried out prior to the site visit, and then updated once on site. The assessment confirmed that a drone was the only option available to inspect the collapse feature that wouldn’t place personnel at risk.

Utilising a standard survey drone, the UAV 365 team carried out a topographic aerial survey of the site. The drone was then manual flown into the feature to gather close up imagery of the edges and basin of the void.

A key aim of the mission was to provide wider site data to allow the client to understand existing topography in greater detail, and infer the topographic situation prior to the collapse event.

Mission Method

Using photogrammetry, the resulting point cloud enabled a detailed understanding of the slope conditions around and inside the collapse feature. The data gathered by the drone also provided significant detail on the likely cause of the collapse.

UAV 365 were able to carry out the mission in this relatively congested area by placing all nearby residents under their control, and maintaining a cordon around the subject area.

As with many of our drone missions, time on site was short and the data gathered was of a high quality and resolution. The resulting data pack was presented to the client using a cloud service, enabling them to access and work with all the assembled information.

Midlothian, Scotland

Our client can use this data to understand the cause of the collapse, plan remediation works, carry out cut and fill analysis and take accurate measurements. A particularly useful asset is the ability to calculate elevation profile data from anywhere in the 3D data. This feature allows measurement of slopes in various locations across the site and leads to a greater understanding of the remediation requirements.