Subsurface Laser Scan Survey of Drainage Culverts
Skipton, North Yorkshire

The Brief

Geoterra was appointed by the Environment Agency to carry out a 3D topographical laser subsurface scan survey of a series of drainage culverts running beneath both property and transport links in Skipton, North Yorkshire.

The survey data was required to assess the location and alignment of the culverts, as well as the clearance between the top of the culvert and the property/transport links located above. The dimensions, integrity and any possible damage to the culverts were also assessed as no previous surveys had been carried out. At the time of the survey, the culverts contained a small amount of flowing water with an area of potentially deeper water also.

The Solution

Geoterra’s experienced geospatial engineers utilised both a specialist FARO laser scanner as well as a GeoSLAM ZEB REVO laser scanner mounted on a backpack with a handheld unit to survey the culverts. The ZEB REVO scans were carried out by walking from a surface baseline at each culvert portal, to the end of the culvert and back again. For the FARO scans, the scanner was set up within each culvert and a 3D laser scan carried out every 30m so that every feature of the culverts would be surveyed. 3D laser scans were also taken at each portal in order to generate a complete 3D model of the drainage culverts. 30m intervals were chosen as the culverts were approximately 150m long and it was split up into smaller sections to ensure accuracy and achieve a high level of detail.

The surveys were geo-referenced to OSGB36 National Grid.  

The Deliverables

Geoterra provided the Environment Agency with a combined geo-referenced 3D laser scan point cloud of the culverts as well as the surface locale surrounding them, in RCS/RCP & DXF for viewing in Navisworks.