Contaminated sediment control in Sydney by Australian Boom & Baffle - Mentanzapl
Australian Wharf & Bridge where engaged by Baulderstone Homibrook to demolish the derelict Mortlake Gas Wharf in February 2005. Due to a number of
issues with contaminated sediments during the overall site remediation the local environment regulator imposed stringent requirements to be undertaken during the
demolition and in particular in relation to the removal of wharf piles.
To ensure that the positive containment was maintained during the entire operation two curtains were installed, both curtains were contoured to the bottom profile:
- The first curtain was installed against the wharf structure.
- The second curtain was moored 20m off the wharf.
- Floating plant engaged in the demolition worked in the area between the two curtains.
Whilst the deployment was relatively calm it was often exposed to strong westerly winds, strong tidal flows and frequent passing by high speed ferries; this
required a robust construction.
In this application a 60kN woven fibrillated fibre polypropylene fabric was used for the skirt. In selecting the skirt fabric the important consideration was the
prevention of sediment blinding during the deployment period. (Alternatively a non woven skirt whilst having an initial higher flow rate tends to blind with sediment
and marine growth and reduce effectiveness over the deployment duration). Additionally the woven skirt retains minimal sediment and facilates low level
contamination spread during removal on project completion.
The skirt was used with AB&B Co type II (enclosed water) float and ballast assemblies. The project duration was 6-9 months, product maintenance required during
project: Nil.
For further information contact:
Mentanzapl
phone: 02 9316 4884
fax: 02 9341 5760
web: www.mentanzapl.com
|
