EDG was part of the CPB/Ghella/UGL bid for the Gowrie to Kagaru Inland Rail project, which was a 128km heavy freight rail line to be constructed through extremely challenging topographical and geological conditions in south-east Queensland. Our services included ground model development, geohazard assessment, tender design of cuts and fills (including design of ground treatments where necessary), subgrade evaluation, earthworks assessment including inputs into the mass haul and excavatability. The work included slope stability analyses for cuts, embankments and foundations, rockfall modelling for cuts, settlement analyses for embankments and foundations, and geomaterial re-use assessment by geological unit and geotechnical unit. Of particular interest were the stability of major cuts through variable geological units (including the tertiary aged volcanics, the underlying Marburg Formation materials and the unconformity between the two) and the durability of cuttings formed in the Marburg Formation materials. Requirements for construction phase services, additional investigations and monitoring were defined, together with detailed evaluation of risks and opportunities for the construction team to consider. The design team worked interactively with the construction team and other design disciplines to cover scope items and provide information for pricing and programing. We were involved in the interactive tender process with the principal to keep them informed of the detailed work being undertaken and specific risk items that required their attention.
