Abernethy Sewer Microtunnel

Client: Water Corporation
Location: Great Eastern Hwy/ Abernethy Rd Intersection, Belmont.
Construction Period: Dec 14 – Jan 15
Ground Conditions: Sand, Clay, Wet Ground Conditions.
Depth: 5 – 6 Metres

Replacement of approximately 84m of existing DN230 VC gravity sewer in various states of collapse by installing a new sewer by microtunnelling closed face methology & relocating adjacent to existing,on completion decommissioning old sewer & commissioning of new.

The scope of works associated with this:


  • Microtunnelling for approximately 88m of 300mm PVC Sewer Jacking Pipe & install 225mm dia PVC SN8 inside,sewer parallel to existing sewer including sleeve, spacers and grouting at each end.
  • Construct 2 new access chambers (1 at each end)
  • Install 3m of between M5951 and new access chamber including external drop
  • Filling and re-benching of existing access chamber M5940

Traffic Management

  • Due to the Receival shaft & proposed access chambers being constructed on intersection of Great Eastern Hwy & Abernethy Rd the traffic management requirements were extensive with both Main Roads & City of Belmont involvement in approving the project TMP.
  • Submit “Application to Undertake Works within Road Reserve”to Main Roads with Traffic Management Plan and Communications plan and obtain approval.

Acid Sulphate testing & Dewatering Mge Plan

  • Sampling and testing of soil and groundwater in accordance with Acid Sulfate Soil and Dewatering Management Plan (ASSDWMP) before commencing works on site including hold points.

Other Works included:

  • Obtain clearance to works permit
  • Bypassing of sewer flows from lateral line into M5940 if necessary
  • Excavation and backfill including compaction testing
  • Disposal of soil and replacement with sand fill as necessary in accordance with ASSDWMP
  • Dewatering in accordance with ASSDWMP
  • Trenchless sewer installation complete including pipe testing
  • Traffic Management on Great Eastern Hwy & Abernethy Road
  • Liaison with Water Corporation for connection to existing assets
  • Verge and pavement reinstatement (to Main Road standards) at launch & receival shafts including testing.