Authors: C. Chua, B. Hawkins, G. Hoffmann and M. Lai, Keller Ground Engineering Contractor
Australian Geomechanics Vol 43 No3, September 2008
Abstract
This paper presents an overview of the geotechnical design considerations and various analytical work undertaken for
the development of the 30 mega-ton per annum (Mtpa) coal stockyard area at the Coal Export Terminal 3 (CET3) on
Kooragang Island, NSW. The coal stockyard of CET3 covers an area approximately 1.2km long by 300m wide. The site
is underlain by soft compressible soil strata of variable thickness.
To support the 21m high coal stockpiles and the stacker-reclaimer machinery loads, the upper ground required
stabilisation/consolidation improvement. The original design of the proposed ground improvement was to use dredged
sand fill won from the proposed berth and wharf facilities constructed for the project to progressively preload the
ground and eliminate the majority of the stability concerns and consolidation settlements during the construction period.
However, due to programme constraints and availability of dredged sand material, ground improvement by dynamic
replacement (DR) was employed to reduce construction time and need for preload material.
The project, believed to be the largest DR project completed in the Southern Hemisphere to date, was contracted to
ground improvement specialist, Keller Ground Engineering on a design and construct basis, based on performance
criteria to limit the post-construction settlements and satisfy the settlement criteria for machinery operation
considerations.
The process of the dynamic replacement work and construction constraints of the ground improvement technique are
presented.
