Successful application a traditional piling technique to achieve an alternate solution to a ground engineering problem.

The project

Greenvale Reservoir is Melbourne’s most urbanised large dam, only 20km north of the CBD. Recently upgraded to meet modern dam safety guidelines, a secant pile filter wall was required in order to link the main dam and wing embankment chimney filters, which despite being adjacent were not at the same slope within the embankment.

The challenge

Determine a suitable methodology to meet the specific requirements of the client design brief.

The solution

The following method was adopted:

  • Install 78No x 1300mm segmentally cased secant filter piles to an average depth of 12m
  • Conduct down hole survey on every pile to ensure sufficient overlap
  • Backfill secant piles with a graded filter sand material in 750mm layers with a base dump kibble
  • Compact each 750mm layer with a 3t free fall drop weight, 3 blows x 3m
  • Extract segmental casing without any vibration

Project Facts

Owner

Melbourne Water

Main Contractor(s)

Thiess Contractors

Keller Business Unit(s)

Keller

Engineer

N/A