Mardi-Mangrove Link Project: Directional Boring under the Wyong River

Posted 1 January 2011

UEA has recently been contracted to install via Horizontal Directional Drilling (HDD) 260 metres of 1200mm PE100 PN16 water main as part of the Mardi to Mangrove link project for John Holland. Originally designed as a micro tunnel, the project has been converted to a directional boring process in order to eliminate the need for deep shafts, reduce the risks associated with micro tunnelling in alluvial ground conditions, and provide a reduction in project costs.

The specific complexities of the project related to HDD include:

  • Installation of 1200mm HDPE PN16 pipeline via HDD has never been installed in Australia.
  • Extremely limited access to the exit side of the bore requiring innovative planning and solutions.
  • Differing ground conditions of alluvial clays and sandstone requiring specialist tooling design and drilling fluid experience.
  • Pipe of this size is a special order product from Europe and has never been handled in Australia.
  • Limited number of calendar days to complete the project with 24 hour operation proposed to complete the works.

Works commenced on site early January 2011 with an expected completion date of March 2011.

Related article:

Landmark HDD Project Gets Underway, Trenchless Australasia