Imprecise, lost or obsolete data and/or information on underground utility services (electrical, water, sewage, fibre etc) directly affects delays, conflicts and interruptions in service, all of which have stern contractual implications. More over the inaccurate geospatial definition of these underground services can lead to serious injuries and fatalities.
Underground utility detection surveys provide for an unobtrusive methodology to deliver critical information on the depth, position and type of underground services.
We employ the world’s leading Ground Penetrating Radar (GPR) technologies to detect and locate underground utilities in accordance international best practises. It should however be noted that the depth of penetration of the GPR is subject to the specific site conditions such as moisture content of the ground, electrical conductivity properties of the ground, compaction of the ground etc. Typically, reliable detection of underground services is restricted to depths of 1.5 – 2 meters in Gauteng. Depth indications can generally be delivered to a 90% level of confidence.
Compared to excavations to expose these underground services the following key-benefits are recorded:
Reduced time and cost to locate the underground utility services
Reduced disruption to the project site / road etc.
Increased safety in the operational execution of the work.
- Planimetric Accuracy – from 50cm (31cm GSD) up to 10m RMSE (subject to the fixing of post identification of survey control)
- Vertical Accuracy (DEM / DSM) – from 50cm up to 30m RMSE
Typical applications will comprise the following (but not limited to):
Confirmation and physical demarcation of underground utility services on site
Accurately determine the geographic location and depths of underground utility services
Update detail topographical survey drawings with the location and depths of existing underground utility services
The detection of underground utility services can typically be delivered in two ways subject to the Client’s specific requirements and constraints, viz –
The demarcation of detected underground services on site
In cases of imminent excavations and/or time constraints a modest approach whereby all detected services are suitably demarcated on-site may be all that our Client’s require. It remains fundamentally important for Client’s in these cases to avail all existing drawings to inform the survey operations and/or avail a representative with local knowledge of the approximate location of these services to reduce time and cost of the survey field operations.
The georeferencing of detected underground services on a Detail Topographical CAD Drawing of the project site
Being the preferred option by many of our Clients all underground utility services being detected are firstly demarcated and secondly accurately surveyed using conventional survey equipment and methodologies in order to record the properties (depth and position) of these utilities on a CAD drawing.
In the case of imprecise, lost or obsolete data and/or information on underground utility services (electrical, water, sewage, fibre etc) it will be advisable to request us to conduct a investigation on all registered servitudes at the Surveyor General and/or acquire all relevant services wayleaves registered with the relevant Municipality.
REQUIRED INFORMATION FOR OFFICIAL QUOTE
We understand that every project, site and client is different – as are their expectations of the required survey deliverables. In order to “sharpen the pencil” and offer you the most cost and time effective geomatics solution, fit for the purpose you require the survey, we would need to acquire the following information from you:
Location of the survey – ideally a “Google Earth Placemark” send to us in kml/kmz format
The purpose of the survey – this serve as an indication of the required level of accuracy required
Required accuracies (planimetric and vertical)
Specific detail which need to be surveyed
Details on the presentation of the survey data
- Hardcopy / Softcopy
- CAD Specifications / Drawing Layout
- Digital data formats required for integration into your design / cad software
Specific logistic constraints getting access to the specific area of interest
SHEQ Requirements (Medicals / inductions / onboarding / PPE / Mine-ready vehicles etc)
Schedule / Program – Should a staggered delivery be required we can work with you to provide critical data at key dates throughout your project.