RISK – Service Strike
Suitable means of service identification may include:
- Dial before you dig (DBYD)
- “as built” drawings
- Electronic detection
- Ground penetrating radar
Striking underground services has the potential to result in serious or fatal consequences.
Before any work can commence, it is important to obtain the most current information about underground services in the area.
Service drawings such as Dial Before You Dig and "as built" Drawings can be used to produce combined services drawings illustrating the location, types or services and boundary of works. These drawings will be attached to the excavation permit for future reference on site.
All services must be treated as live until sufficient evidence is received to prove otherwise.
Contact local authorities, utility and service providers to confirm exclusion zones or safe working distances (also known as safe approach distances) for existing services.
Excavation Permit
An excavation permit must be completed for any excavation activity. This includes any man-made cut, cavity, trench or movement or placement of soil or other surface material by removing, boring or forcing objects into the ground or earth surface.
An Excavation Permit must be completed by the Permit Controller. The permit Controller must have experience in working with utilities, be proficient in interpreting services drawings and have completed the John Holland Excavation procedural Awareness Training.
Excavation Permits can be valid for a maximum of 28 days from the service drawings date of issue.
A copy of the excavation permit and associated combined services drawings must be held on site at all times by the work crew performing the work.
See the Excavation Permit Flowchart here
Example of combined services section of permit completed:
Obtaining and checking structural as-built conditions.
Before excavation design or works commence, care should be given to check and obtain the As-built structural drawings or information. This will identify clashes or impacts in the vicinity of the excavation, which will drive how the excavation and/or ground support will be designed and adopted.
For example: The design of an excavation in the middle of vacant land will be different to the design of an excavation located near or alongside a basement.
In regard to working with an underground space, piles and other infrastructure may be found to be within the excavation or the support criteria. This detail will need to be captured within the design and fed into the Permit to Tunnel to ensure the clash is detected and avoided/managed.
Related GMRs
2.6 Ensure a Permit to Tunnel is approved and permit controls are in place prior to commencing tunnelling work
4.A Treat all exposed electrical parts and conductors, including earthing conductors, as live until proven otherwise
Related Procedures / Forms
Excavation and Trenching Procedure
Temporary Works Management Procedure
Permit to Tunnel