Stability study of open pit slope at Highland Valley Copper Mine

This paper presents a stability study of an open pit slope at Highland Valley Copper Mine in British Columbia, Canada. The slope analyzed was 575 m high with 20% of it still to be mined at the toe. Dominated by toppling features and other geological units, the slope presents a complex structure. The Valley Pit west wall was studied using BSM, a Block-Spring Model for jointed rocks. Several scenarios of the slope were investigated including changing rock properties, tectonic stresses and ground water level. The BSM model clearly indicated a changing structural behaviour along the slope with varying movement zones. These zones are divided into toppling structures in the upper portion and sliding structures in the lower portion. These movement “zones” interact with each other and form a complex deformation behaviour. The upper toppling failure zones predicted by the numerical model were confirmed in the field, which indicated that the BSM model is a useful tool for rock slope stability analysis.