Even though waste dumps are probably of the smallest productive relevance for mining operations, they are an operational reality and are under scrutiny from the perspective of security and environmental impact. If one also considers that these works can reach significant dimensions, then it is essential to apply state-of-the-art tools to evaluate their stability. Depending on the topographical and geotechnical conditions of the sectors selected for disposal of mine waste, and also depending on the geometry of the designs under consideration, the stability analyses can be performed by means of two- or three-dimensional representations. This paper deals with three-dimensional stability analyses of five waste dumps located in sectors adjacent to the Chuquicamata Mine open pit. Chuquicamata, the world's largest open pit mine, is located in Northern Chile, in the Atacama desert, one of the driest regions in the world. Analyses were performed using the three-dimensional finite difference code FLAC~(3D). Some preliminary and intermediate analyses were also performed using the two-dimensional version of the code, named FLAC. One of the main reasons for the mine to request the analyses was the presence of significant cracks in the surface of some large waste dumps. Although these cracks are believed to result from natural material settlement and are not necessarily indicative of slope instability, it was important to perform a study to confirm this notion through the use of conservative shear strength properties and safety factor determination. The study included an exhaustive review of bibliographical data about geotechnical properties for these materials. The analyses also lead to an interesting finding about the impact of the curvature of dumps on their stability.
展开▼
