Services – In-Ground
Purpose and Scope
The purpose of this procedure is to ensure that all inground services on Hansen Yuncken projects are constructed in accordance with relevant Standards, project documentation, and HY processes, and undergo all required quality control verifications. This includes the installation of new services and redirection/upgrade of existing services.
The scope of these works includes excavation/trenching, laying bedding materials, installing pipes/conduits/pits, and backfilling materials.
This procedure is to be read in conjunction with the Underground and Overhead Services Procedure, Electrical Supply and Equipment procedure, and respective HYer Standards which document the safety requirements associated with these works.
When Isolating or Energising services, the Isolation and Energisation procedure applies.
Responsibilities
Project Manager
- Ensuring design changes are assessed for constructability risks
- Ensure any design constructability risks are assessed, controlled, and documented in the Project’s Risk Register
- Ensuring any constructability risks identified are communicated to workers performing the work and the HY project team
HY Project Team
- Obtaining and reviewing project documentation, drawings, and specifications
- Managing workflows to document RFIs and design changes
- Managing the project’s document registry and communicating documentation to relevant parties
- Communicating requirements for submittals, warranties, and inspection and test plans to Subcontractors and other parties as applicable
- Ensure nominated subcontract users are registered in the QA platform and invited to the Project Profile
- Ensuring relevant quality control pre-work checks are complete prior to starting works
- Ensuring any applicable hold and witness points are in place and adhered to
- Receiving and controlling submittals, warranties, and inspection and test plans
Subcontractor Supervisor
- Ensure personnel responsible for using the QA platform are registered and have means to access the platform via mobile or desktop devices
- Ensuring relevant quality control checks are complete at various stages of work (pre, during, post)
- Ensuring any applicable hold and witness points are adhered to
- Providing any required submittals, warranties, and inspection and test plans
Quality Verification
Hansen Yuncken predominantly utilises Autodesk platforms (BIM360 and ACC) to carry out quality control checks and verifications. Subcontractor supervisors or nominated representatives must have a registered Autodesk account and be invited onto the Project Profile by the HY project team.
The Services – In-ground Checklist in the QA platform is to be completed prior to and throughout the relevant stages of works. HY representatives are responsible for completing the header and site preparation sections. The relevant services and civil subcontractor representatives are responsible for completing the remaining sections respectively. All hold points must be adhered to and verified by the HY representative to proceed. This is to ensure that all works have been verified and completed as specified.
Guidance on the use of software for Subcontractor users can be accessed via the Onboarding Induction and Training Procedure.
Note: Defence Projects and select Government Projects may have unique requirements regarding Quality Control and the use of software packages to carry out verifications. The agreed methods and software packages will be determined at Project Commencement considering the specific project needs and client requirements.
Preparation
Project drawings and specifications will detail the locations and requirements to construct wet areas including set downs, penetrations, finishes and materials to be used.
The latest revisions of drawings and specifications are to be referenced for the works, which are to be provided to the subcontractors carrying out the works.
Approvals
Submittals, samples, and materials are to be identified, reviewed, and approved by the respective responsible parties in accordance with project specifications prior to works beginning. Any changes are to be captured via appropriate channels for the project (e.g., Aconex Workflow) and communicated to workers.
For the installation of inground services, bedding material grading certificates will be required to be submitted for approval. Samples for pipes, conduits, and pits may also be required.
Site Preparation
The following checks need to be verified prior to any works commencing, including ground penetration:
- The latest Before You Dig Australia (BYDA) drawings have been obtained, reviewed by HY, and are in date. Note: not all infrastructure asset providers are BYDA members.
- Existing services have been identified and recorded (i.e., marked on a services location plan)
- Ground conditions/excavations have been approved for inground services installation.
- Bedding material is per specified requirements.
- Bedding material has been laid to correct thickness.
Refer to the Underground and Overhead Services procedure for safety requirements.
Pipes/Conduits/Pits
Materials used for the construction of inground services must be approved for use in accordance with specifications. Material samples may be required for client approval. Materials delivered to site must match approved samples and be suitable for use (i.e., not expired, compatible, in suitable container etc).
Pipe and conduit material checks to be completed include:
- Pipe or conduit material is in accordance with specified requirements.
- Pipe or conduit has been laid to correct level and gradient.
- Pipe or conduit location and alignment is in accordance with design requirements.
- Minimum separation of underground services is achieved.
- Adequate draw strings for electrical cable (if applicable) have been installed.
- Pipe or conduits have been installed without damage.
- Pipe or conduit joints have been appropriately treated/glued.
- Thrust blocks (if applicable) are installed as specified.
- Pits have been constructed in accordance with specified requirements.
- Pits are installed in correct location and orientation.
- The direction of services entering pits is as per Specification and Manufacturer’s requirements.
Note: Precast elements such as services pits are to be fabricated in accordance with the Precast Fabrication and Installation Procedure.
Backfilling and Finish
Prior to covering or backfilling services, photographs are to be taken to record the placement of services. These are to be uploaded to the relevant section in the Services – In Ground BIM360 checklist and provided to consultants if applicable or requested.
When backfilling, services must be visually identified with underground marker tape that complies with AS/NZS 2648.1 and installed per AS/NZS 3000.
The following is to be verified to ensure inground services and pits have been installed in accordance with specifications:
- In-ground services have been inspected by the relevant authorities/consultants prior to backfilling (if applicable)
- Cover over pipe or conduits are in accordance with specified requirements.
- Marking tape is the correct width, colour and in accordance with as 2648.1, and installed at the correct depth.
- Backfill material is in accordance with specified requirements.
- Backfill material has been placed in correct layer thicknesses.
- Backfill material has been compacted to the specified requirements.
- Trench backfill compaction tests have been successfully completed.
- Air pressure leak tests (if applicable) have been successfully completed.
- Hydrostatic tests (if applicable) have been successfully completed
- Surfaces disturbed during services installation have been adequately reinstated/repaired.
- Protruding services are physically protected from future construction damage.
Specifications and Compliance
Current Project Specifications are to be used to confirm all approvals, samples, and submittals required for the project. Project Specification requirements are to be entered into the Project’s Compliance Schedule.
The following approvals/samples may be required:
- Pipe material
- Pit Material
- Bedding material
- Services Pits
The following supporting documentation or submissions may be required from the subcontractor:
- Bedding material grading certificate.
- Pipe/conduit compliance record/certificate.
- Photographs of installed services prior to backfill.
- Authority/Consultant inspection report.
- Air pressure leak and hydrostatic test results.
- Manufacturer’s Warranty Certificate
- QC and Inspection/Test records from Tiling, Vinyl and glazing Contractor uploaded to BIM and attached to the relevant sections of the checklist
- Certificates of Installation for completed works
Hold/Witness Points to be adhered to throughout works:
- Verify in-ground services have been inspected by the relevant authorities/consultants prior to closing up (if applicable)
- Verify trench backfill compaction tests have been successfully completed.
- Verify air pressure leak tests (if applicable) have been successfully completed.
- Verify hydrostatic tests (if applicable) have been successfully completed.
Definitions
BYDA – Before You Dig Australia
RFI – Request for Information
References
- AS/NZS 3000 – Electrical installations
- AS 2648.1 – Underground marking tape non-detectable tape.
- AS 3798 table 8.7 – Guidelines on earthworks for commercial and residential developments.
- AS 1289.5.4.1 – Soil compaction and density tests—Compaction control test—Dry density ratio, moisture variation and moisture ratio.
Associated Checklists and Documents
- Services – In-ground Checklist (Autodesk)
- Underground and Overhead Services Procedure and HYer Standard
- Electrical Supply and Equipment Procedure and HYer Standard
- Isolation and Energisation procedure