Abstract
The process followed by geotechnical engineers when designing open-pit mine slopes requires a specialized knowledge of the geology of a prospective orebody and the host terrain. The sooner this information is obtained, the earlier that geotechnical engineers will be able to prepare conceptual slope designs, which will enable the deposit owner to assess whether the project is technically feasible and economically viable. The first information will usually come from early district- to mine-scale outcrop mapping and drilling by exploration geologists. To be of maximum use to geotechnical engineers, the data collected by exploration geologists must be recorded in a manner that supports the rock mass classification and strength assessment used by geotechnical engineers for mine design studies. The essentials that exploration geologists need to know when performing this task underscore why close working relationships between exploration geologists and engineering geologists are essential to improve the geotechnical outcomes in open-pit mines.
Our objective is to encourage exploration geologists to extract the maximum mining-related data and information possible from rock outcrops and exploration drill holes, within the limitation of the exploration budget for discovery and mineral resource definition. The types of data that geotechnical engineers use in open-pit slope design include geologic, structural, rock mass strength, and hydrogeological data. Most exploration geologists are not trained as geotechnical engineers, and collecting geotechnical data of the quality required by engineers will be beyond the responsibility and experience of many of them. However, early discussion with a geotechnical engineer will assist exploration geologists in designing a drill core logging format that will collect the most important data that the engineer requires, within the constraints of discovering and defining the mineral resource.