Application of monitoring data for the prediction of the time to failure and risk management

Abstract

During the past decades, excavation in open mine has been planned based on "more extraction with low cost". This resulted to the poor management of excavation and consequently, slope instability in many open pit mines. Anguran zinc and lead open mine in Zanjan Province, northwestern of Iran is an old mine that has been excavated since 1940 and is one of the examples of improper management that has encountered to several instabilities in its northern and western flanks. The economic importance of the operation of this mine and high risk of landslide occurrence put this mine as of the main concerns of the local governor. The investigation has been done through detail field study together with high precision monitoring of unstable blocks. It was found that the main landslide in this mine is a creep type of motion that caused by overlying a block of hard limestone on a low strength clay bearing schist. It was also concluded that in a creep type of landslide, independence of the rate of motion from its initial triggering factor such as rain is a good indicator for predicting the time of rapid failure and for controlling the risk by proper evacuation plans. © Springer-Verlag Berlin Heidelberg 2013.