The Kidston Pumped storage Hydro Project (K2H)

Engineering Geology and Development of a 3D geological model: methods used and lessons learned

Alistair Schofield

The Kidston Clean Energy Hub is being developed by GENEX Power Limited at the former Kidston open-cut gold mine near the Copperfield River in North Queensland. Construction is currently being undertaken by the McConnell Dowell and John Holland Joint Venture. The project includes a 250MW pumped storage hydro-power station (“K2H”) integrated with a solar farm. Construction of a 300 m deep intake, cable and vent shafts, power and transformer caverns, a 650 m long tailrace tunnel and over 2.5 km of tunnel within the Pre-Cambrian Einasleigh metamorphics paired with an upper storage reservoir is required as part of the project. This presentation describes the engineering geology of the site and the methods and aims of development of a 3D geological model during various stages of the project. Initial understanding was derived from project specific boreholes with additional data including exploration hole records and assay data, field mapping and analysis of drone collected photogrammetry data being required to allow further validation of the geological model. Geophysical anomalies coupled with old site plans, constrained the location and geomechanical significance of faults. Reconstruction of pre-mine topography from contours preserved on exploration maps provided a sub-waste topography which was invaluable for designing the embankment cutoff trench. The model has assisted greatly in the scoping of further geotechnical investigations and analysis of the generated data and optimisation during detailed design. The project has successfully utilised traditional and innovative methods of engineering geological data capture.

About the speaker

Alistair Schofield Associate & Technical Director of Engineering Geology, GHD

Alistair is a Technical Director of Engineering Geology and Associate at GHD. He has over 17 years engineering geology experience and has worked on a wide variety of projects in the UK, Australia, the Philippines and New Zealand. His experience includes ground model development for dams and tunnel projects, geotechnical investigations, landslide assessments, geological and geomorphological mapping and other geohazard assessments. He graduated with a first degree in Geology at the University of Edinburgh in 2002 and supplemented that with an MSc in Engineering Geology from the University of Canterbury in New Zealand in 2014.

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