Terrain hazard around the Ok Tedi copper mine, Papua New Guinea
Located in the remote Star Mountains of Western Province, Papua New Guinea, the Ok Tedi open-cut copper mine operates under conditions of particular topographical and geotechnical adversity. Slopes are frequently steep, rocks are highly fractured and weakened due to tectonics and weathering, and rainfall is world record-breaking, with annual totals exceeding 10m in the vicinity of the mine (Jones & Maconochie 1990). The mine is planned to occupy an area of 2km diameter with a depth of 500m at an altitude of 1800 m a.s.l. The mine supply corridor, along which power, food and other essential materials are brought in and copper concentrate is piped out, is 160km long, and is itself at risk from slope, flooding and erosional hazards.
The threat posed by these hazards to the operation of the mine and the viability of its supply corridor has been recognized and evaluated by the geotechnical department of Ok Tedi Mining Ltd (OTML) since the project’s inception. However, the severity and proximity of this risk were perhaps not fully realized until 1989 when a rock avalanche involving perhaps as much as 70 × 106 m3 of material occurred within a very short distance of the mine office. The collapse of the mountainside was dramatic and was considered to have been responsible for the seismic event recorded at the time of failure in Port Moresby, approximately 800km away. Although the infrastructure of the mine was not directly affected by this failure, it served as a catalyst for a
Figures & Tables
Land Surface Evaluation for Engineering Practice
This volume presents a collection of papers on techniques and case studies in land surface evaluation for engineering practice written by specialist practitioners in the field. The volume arose out of deliberations by the Second Working Party on Land Surface Evaluation set up by the Engineering Group of the Geological Society in January 1997 and chaired by Dr. J. S. Griffiths. The book examples of cost-effective methods for collecting land surface and near surface data prior to carrying further detailed ground investigations of engineering geologist, geotechnical engineers, geomorphologist and planners who have the responsibility for planning a designing investigations of potential sites of development.