Earthquake is a major trigger for instability of natural and man-made slopes. Often the instability of slopes due to an earthquake causes mass failures in open mines which in turn stops mine production. Therefore, large mines should be designed for possible future earth shakes. Choghart Iron Mine is one of the most important and large active mines in central Iran which has an important contribution to the overall countries iron ore production. The possibility of a large size mass movement at its southern wall has raised concerns about the stability of the mine and its continuous production which necessitated a research into this subject. Presence of numerous faults and major weathering in this zone and also occurrence of few smaller size slope instabilities together with the fact that the mine is located in a very active seismic region necessitated a dynamic slope stability analysis in addition to usual static study. To account for all the important factors in this stability analysis, massive in situ joint mapping and rock mechanics studies have been performed to gather the basic information required for a numerical analysis. A seismic study is also performed to investigate the effect of dynamic loading on the safety factor in case of a possible earthquake. The present study shows that most parts of the southern wall will be unstable if it is subjected to an earthquake similar to the ones that have been recorded in the region’s history.

The earthquake triggers failure in slopes that have been stable otherwise. However, most of the times, earthquakes can destabilize slopes that have a safety factor close to 1 due to weathering, erosion changes in slope geometry by man (such as road cuts) or effect of water such as agriculture on a slope.