Engineering Surveying Services

Underground utility surveys use a range of non-destructive techniques to locate sub-surface utility pipes, ducts, and cables. The most common techniques are Electromagnetic Locating (EML) and Ground Penetrating Radar (GPR). 

Electromagnetic locating uses a sensitive array of antennas to detect electromagnetic signals travelling along underground metallic sources such as pipes or cables. These signals may be being emitted from the source itself (such as a low-voltage electrical cable) or they may be artificially induced using a small generator. The equipment used is a more sophisticated version of that used for basic cable avoidance sweeps. 

Ground Penetrating Radar uses a radar emitter to send a stream of radar waves into the ground. If the waves hit an obstruction part of the signal bounces back and is picked up by a sensitive antenna on the radar unit. 

Both techniques have their advantages and disadvantages; EML is usually better for tracing thin metallic objects such as cables, whereas GPR is better for tracing larger, non-metallic services such as sewer pipes. The success rate of a utility survey is heavily dependent on the site’s ground conditions and on the skill of the surveyors undertaking the survey. 

At Via we deliver our utility surveys to the PAS128 standard, as recommended as best practice by industry bodies such as The Survey Association and the Royal Institute of Chartered Surveyors. To support this, all our surveyors are trained and certified to a minimum of ProQual QCF Level 3. 

Point clouds are dense 3D point models that have been measured using a laser scanner. They are usually used in conjunction with other survey instruments for topographical, building or monitoring surveys, but the point cloud dataset can also be a useful deliverable. Clients such as urban planners and architects can use colourised point clouds for 3D visualisation work, for example, a designer working on a town centre renewal project could overlay their design onto an existing point cloud dataset to put their new designs in the context of the local environment. 

Setting out is the process of marking out the positions of design features on the ground in readiness for construction. Accurate marking out is essential to avoid expensive and wasteful mistakes during the construction phase of a project. Via’s survey team has many years of experience of setting out civil engineering works, particularly on highway, urban renewal, and drainage projects. They can take your design drawings and mark them out to enable your construction teams to turn your design into reality. 

As the urban environment becomes more and more complex, it’s imperative that public bodies and utility companies have detailed and up-to-date information on their assets. Via’s surveyors can use a variety of techniques to capture the size and location of these assets, using photographic and other metadata to generate an asset report. 

Once your project is complete, Via’s survey team can supply you with accurate, independent drawings of the finished works. As-built surveys are a critical part of quality control procedures and can act as the basis for handover documents to the client. 

Site Monitoring involves using a range of techniques to identify and measure changes in the position or shape of a feature. This could be the wall of a building, a retaining wall, a cliff face, or any other structure where there is a risk of failure. 

Traditionally the monitoring would be achieved by installing a series of control points across the area of interest. These are then measured at regular intervals according to the client’s requirements. The results can be issued as a spreadsheet with graphs to help visualise any movement. For more complex features, a laser scanner can be used to capture a 3D surface which can then be compared to measurements taken previously. 

At Via we have a long history of site monitoring; one of our monitoring campaigns has been running since 1994!