High Waste Rock Dumps — Challenges and Developments

The recent experience with the design and operation of very high waste rock dumps (WRD) is discussed with special emphasis on the determination of the geotechnical characteristics of waste rock subject to high confining pressures and eventually also subject to in situ leaching. The results of drained and undrained triaxial tests on samples of waste rock, carried out on a recently built apparatus capable of accepting samples of 1 m in diameter and up to 203.2 mm size and confining pressures up to 3 MPa are commented on. The use of these results in the analysis of possible static liquefaction is also discussed as well as the design approach to consider earthquake effect and final closure of the facilities. With the significant increase in production levels of metallic mining, particularly in mountainous environments, the necessity for larger and higher WRD raises numerous challenges. Structures with heights of 400 to 500 m have already been reported, and projections for future constructions reaching 700 m necessitate meticulous attention to geotechnical behavior under extreme pressures. Thus, the industry, geotechnical practitioners, and researchers are faced with a major challenge to find adequate solutions to the various associated problems.