Ground Penetrating Radar (GPR) Utility survey at a Power Station
Ironbridge Power Station – GPR
Following the shutdown of Ironbridge Power Station in 2015, work needs to be undertaken as part of the decommissioning of the site for the purpose of demolition. This started in July 2017 with the removal of the conveyors and associated workings. These transported the coal across the site safely when the power station was in use. The next phase, is that the rest of the site will be demolished by the end of 2018.
This phase of demolition involves the main transformer buildings on the site, currently in operation providing a boost to electricity for Shropshire.
Severn Partnership were commissioned to locate and survey any powerlines or utilities after these initial works and prior to any further demolition. This is usually one of the first phases of any demolition of infrastructure and assets to ensure the disconnection of all major service routes.
To ensure this is done correctly, the client needed to ensure the survey was compliant to PAS128 level B. This approach uses multiple detection methods to provide a complete map of what is beneath the surface including the latest technology Ground Penetrating Radar (GPR), prior to any excavation during the demolition. Severn Partnership were asked to do this element of the survey due to our expertise and experience.
Using statutory records, the client had cut all known connections entering the building. Using GPR, we could check these connections had been correctly disconnected and there were no services entering the building that had been missed off the statutory records.
The area required for GPR was approximately 15,000m squared, which needed to be done quickly, to fit into to the project programme. To do this a new method of data capture was needed without compromise on quality.
The solution: Stream C
The Stream C is the compact array solution for real-time and post-processing 3D mapping of underground utilities. Thanks to the increased level of accuracy, provided by a massive antenna array, Stream C can detect pipes and cables rapidly and efficiently. The Stream C vastly increases productivity with surveys only needing to be done in one direction to ensure optimal detection of both longitudinal and transversal pipes, compare this with single antenna systems that that need to be pushed in both directions. This saves time and reduces costs, while improving the data quality.
Mass data collection for utilities survey using stream C ground penetrating radar (GPR)
3D subsurface plan CAD plan
Results and Benefits – LeanGeomatics
Severn Partnership were able to confirm that all known services indicated on statutory records of the site had been correctly disconnected. The Survey also found that services had been missed that were not present on the statutory information. This shows how unreliable and inaccurate statutory records can be, and why a full Utility Detection Survey must be carried out if any construction work is to take place.
#LeanGeomatics is term to ensure the client gets value for money, by making data capture and work flows as efficient as possible. By using the innovation, technology and workflows described in this case study, our clients are getting the best services available. Saving time onsite, bringing the delivery date forward and often being able to mobilise quicker by removing something for example, Traffic Management. This also has a positive impact on costs by reducing indirect spend.
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Finding what you can not see – Power lines below the ground using GPR