Test Methods and Specifications
Subsoil Drainage
- Publication no: ATS-2255-25
- Published: 24 January 2025
- Edition: 1.0
- PDF (free) Download
Austroads Technical Specification ATS 2255 sets out the requirements for the construction of the following types of subsoil drainage systems:
- ‘Trench Drains’, which comprise of a trench which is backfilled with Filter Material (either permeable aggregate or No-fines Concrete). Usually, the trench is lined with geotextile fabric and a Strip Filter Drain or perforated drainage pipe is placed in the Filter Material.
- ‘Interface Drains’, which are Trench Drains used to drain the interface between pavements with different structures. The interface may be in a transverse or longitudinal orientation.
- ‘Edge Drains’ which remove water in rigid pavements from the interface between the base and subbase.
- ‘Intra-pavement Drains’ which are constructed under a pavement layer to remove water from the pavement layers, typically on steep grades and sag curves.
- Proprietary sheet drainage systems placed against a structure to prevent the build-up of hydraulic pressure in the backfill.
This technical specification can also be downloaded as a Word document.
- 1. Scope
- 2. Referenced Documents
- 3. Definitions
- 4. Quality System Requirements
- 5. Materials
- General
- Aggregate Filter Material
- 6. Construction
- General
- Handling of Geotextiles and Subsoil Drainage Pipe
- Excavation of Trenches
- Placement of Geotextile, Subsoil Drainage Pipe and Filter Material
- Installation Trial
- 7. Outlets and Cleanouts
- General
- Outlets at Stormwater Drainage Structures
- Outlets at Batters
- Access Points for Flushing
- Flushing and Inspection of Subsoil Drainage Pipe
- 8. Sheet Subsoil Drainage Systems
- 9. Conformity
- Geometrics
- Reporting
- Annexure A: Summary of Hold Points, Witness Points and Records
- Amendment Record
Related publications
ATS-2170-25
ATS-2135-25
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