2013 Australian Coasts and Port Conference – 2 Papers Presented by Water Technology
Members of Water Technology’s Coastal and Environment team are attending the 2013 Australian and New Zealand Coasts and Ports conference in Manly September 11 – 13, 2013. The team has two papers in the conference proceedings, to be presented by Principle Engineer Tim Womersley.
Investigation of Geotextile Offshore Breakwaters to Enhance Mangrove Re-vegetation and Shoreline Protection in Western Port, Victoria
Tim Womersley and Darren James (DEPI)
The paper describes investigations undertaken to examine whether offshore geotextile breakwaters could be used within Western Port to (i) enhance mangrove revegetation survival via attenuating wave energy and accreting sediment in their lee, and (ii) protect shoreline beaches and cliffs from wave driven erosion processes. Numerical modelling of hydrodynamics, waves and sediment transport was utilised to compare various breakwater designs while giving consideration to a range of ecological and physical parameters for mangrove survival. The results indicate that a series of three overtopping breakwaters showed potential to enhance mangrove revegetation survival, as well as provide shoreline protection (Figure 1).
Adaption of Breakwater Design Due to Material Availability During Construction
Andrew McCowan, Elise Lawry, Gerry Byrne (Vantree), and Nick Eddy (BMD Constructions)
The paper describes the work carried out to remedy problems caused by the density of the armour rock supplied for construction of the harbour breakwaters being well below that of the design specifications. The original design of the rubble mound breakwaters had been optimised by physical model testing, however during construction it became evident that the density of much of the rock armour being used on the breakwaters was somewhat lower than that specified in the design. Hudson’s equation indicated that the armour rock weight would need to be almost doubled to retain the stability characteristics of the original design. Further investigations and physical modeling confirmed revised design which could be implemented mid construction ensuring minimal downtime or reworking of the breakwater.
More information can be found in this article in The Australian National Construction Review