Cape Preston Port

Project: Geotechnical Assessment of Cape Preston Port
Location: Cape Preston, Australia
Client: Sandwell Engineering Inc.

In 2008, MEG Consulting Limited (M+EG) was contracted by Sandwell Engineering Inc. to provide geotechnical input to the possible foundation options at Cape Preston, Australia.  The project includes the assessment of the dredged spoil fill used for the desalination plant, the piled foundations of the berthing dolphins, foundation considerations of the breakwater (from the shore to the loading berth) and the barge loader foundation.

The scope of work provided by M+EG considered the following:

• Review available laboratory testing results of the dredged spoil fill and provide geotechnical recommendations for the use of the dredged spoil fill;
• Analyses for the rock-socketed piles for the proposed berthing dolphins;
• Perform foundation analyses for the proposed breakwater and the barge loader foundations.


Project Highlights:

•  The dredged spoil fill has a high carbonate content (>75%), which can form soils with collapsible structures and with brittle contacts.  Recommendations have been provided for using the dredged spoil fill and ground improvement options have also been proposed in combination with the use of the dredged spoil fill.
• The axial pile capacities of the rock-socketed piles have been calculated for both compression and tension.  In addition, the axial and lateral load transfer (t-z and p-y) curves for rock have been provided to Sandwell for structural analyses.
• Settlements were estimated along the breakwater which is to be constructed using the rockfill dredged on site.  The dredged rockfills are considered to be calcirudite and calcarentie, which are highly weathered.  Hence, the settlement resulting from creep of the rockfill was also considered.  This was particularly important for the construction of pipelines and utilities within the access breakwater which were to be installed prior to transportation of large loads along the rockfill.  The large loads result from the off-loading of modules to be transported to the mine site for construction of the plant infrastructure.