Mine groundwater control and slope depressurisation methods at Ok Tedi in one of the highest annual rainfall areas in the world

摘要

The Ok Tedi Mine is located in the Western Province of Papua New Guinea. The average rainfall (1985-2010) is between 8m and 10m per annum with a maximum of 10.7m (2005) and minimum of 4.7m (1997). From 2007, boreholes have been drilled and fully cemented vibrating wire piezometers with data loggers were installed in these holes to monitor the piezometric head in the different lithologies. Packer tests to estimate hydraulic conductivity values were conducted. The software FEFLOW and Phase~2 were utilised to model the pore pressure distribution in the pit walls and the results were used to access the pit wall stability.