Culverts are a common feature of the built environment, managing the flow of water around and beneath buildings and infrastructure. They are rarely seen, therefore keeping them well maintained is vital to prevent issues such as flooding, sink holes, or road and rail line collapse.
Replacing a culvert is a major undertaking; hence a practical and cost-effective alternative is to create a slip lining – a replacement lining for the culvert which is placed inside the existing structure without the need for excavation works.
In Carmarthenshire, a culvert beneath a busy A-road was identified as in need of refurbishment. As a result the local council commissioned specialist marine and civil engineering contractor EDS to investigate the structural form, taking precise measurements, so that a design could be prepared for installing a slip lining.
EDS and Glanville Geospatial Services have worked together on previous occasions, and so we were engaged to produce sectional CAD drawings of the culvert along its length, with measurements of its inner profile. We were also asked to produce a point cloud and to plot the route of the culvert onto an existing topographic survey.
To deliver the work, we sent two of our geospatial surveyors to site, Jake and Sarah, supported by a confined space safety and rescue team from EDS.
Using our Faro Focus S150 laser scanner and Trimble SX10, the surveyors worked along the culvert capturing data above and below the waterline. This data was used to create sections at regular intervals along its 21m length. The sectional drawings created can be seen in the image; and these clearly show the deformation of the culvert in various places.
Our survey deliverables provided the ultimate client with the data required to help them accurately design the slip lining taking this deformation into account. This important work will help to preserve this section of Welsh watercourse for years to come.
