Influence of block cave mining on pit slope deformation mechanisms

• Main Author: Ahmed, Haitham Magdi
• Language: English
• Published: University of British Columbia 2009
• Online Access: http://hdl.handle.net/2429/7385

Several mining operations are considering the switch from surface to underground in order to mine deeper resources. When making this switch block cave mining is often considered to minimize costs. The primary objective of this study is to investigate the mechanics of rock slope movements and failure in response to the block caving process. Different potential failure modes are investigated as a function of the orientation of the jointing pattern. The impact of two different caving locations on slope stability will be investigated: one where the cave is located under the toe of the slope, and another where the cave propagates upwards behind the crest of the slope. It is found that the position of the cave plays an equally major role in how the slope behaves and displaces. The potential of the toppling failure mechanism, flexural toppling of slender blocks or flexural block toppling of rocks with cross-joints, is characterized by inward movements of the rock mass toward the cave beneath the toe. However, huge vertical displacements on the upper part of the slope are distinguished as an influence of the cave behind the crest. Moreover, a consistent horizontal and vertical slope displacement toward the cave beneath the toe associated with sliding movements gives evidence that the cave zone influences the overall slope to move toward the toe.