Scarborough Beach Drainage Microtunnelling DN500 & 900

Client: City Of Stirling
Location: Scarborough Beach Rd & West Coast Hwy, Scarborough.
Construction Period: Aug 13 – Nov 13
Ground Conditions: Sand, Calcarenite Rock, Limestone Pinacles.
Depth: 5 – 6 Metres

Major improvements to the Scarborough Beach foreshore area were required by the Scarborough Environs Area Strategy (SEAS) Master Plan.Improvements to the existing drainage included the removal of two (2) piped drainage outfalls at the beach. The revised disposal method for runoff from the existing local drainage catchment was the construction of an underground retention (infiltration) basin within the existing lower grassed foreshore reserve located opposite Manning Road.

The drainage improvement works included the installation of a supplementary piped outfall system from a low point in Scarborough Beach Road to the proposed underground retention basin.

To minimise traffic & community disruption including use of the foreshore area during construction of the pipework it was decided that approx 342m of the piped drainage within the Scarborough Beach Road reservation and coastal foreshore be installed using microtunnelling closed face slurry trenchless technology.

Concrete drainage jacking pipes were required & calculations based on ground conditions,drive lengths 7 likely surface friction on pipes undertaken prior to calling up the required safe jacking load pipes.

Summary of Work Included

  • Installation using microtunnelling techniques approx 342m x DN900 concrete pipe
  • Installation using microtunnelling techniques approx 22m x DN500 concrete pipe
  • Supply and installation of 4 No concrete manhole chambers
  • Supply and install connection pipework to 2 No existing manholes.
  • Reinstatement of Launch & receival shafts at new access chamber locations.