Frieda River Mine Waste Rock and Tailings Storage and Hydroelectric Power Study
SRK was commissioned to undertake a multidisciplinary selection phase design of an integrated hydroelectric power, mine waste rock, and tailings storage facility to be developed for the Frieda River copper-gold project. The hydroelectric power generated will supply the mine, with excess power available for sale and distribution into the Papua New Guinea power distribution network. Complex 3D limnological modelling, including water and load balance studies, were undertaken to characterise the behaviour of the mine waste rock and tailings planned for sub-aqueous disposal into the hydroelectric reservoir. The unique project setting presented a range of extreme challenges including the remote site location, 8 m of rainfall per annum, high seismicity, and steep terrain. A series of containment embankment configurations were analysed to ensure that the optimal design for the facility was devised in this setting.
The integrated storage facility features a 190.5 m high asphalt core rockfill dam (ACRD), two diversion dams, a 35.5 m high cofferdam, two diversion tunnels, a hydropower intake and conveyance system linked to a turbine facility, and a side-hill spillway. The proposed ACRD is higher than any other currently in operation in the world. Designs were prepared for the dam, appurtenant structures, and rockfill quarry. A geotechnical investigation campaign was undertaken to characterise the sub-surface founding conditions, to assess the stability of dam abutment slopes, to provide design inputs for tunnels, and to identify a source of rockfill suitable for use as construction material. The SRK team conducted field investigations, which included geo-mapping for structural interpretation, geotechnical drilling, logging of drill core, material sampling, laboratory testing, permeability testing, and installation of vibrating wire piezometers. SRK also undertook project management, hydrogeological reviews, regional hydrology assessments, geo-hazard assessment, risk assessments, and deformation and seepage analyses.
