Abstract:

To improve the slope stability of an open-pit mine stope, the stope was divided into 3 zones by taking into account key factors such as engineering geological conditions. For the profiles of each zone, seepage field analysis was conducted. On the basis of the seepage field, the Bishop method and M-P method (both limit equilibrium methods) were adopted to carry out slope stability analysis under three scenarios, respectively: self-weight + groundwater, self-weight + groundwater + blasting vibration force, and self-weight + groundwater + seismic force. The results show that the seepage field was distributed uniformly overall in the topographic direction, and the seepage paths presented a gentle curved transition. The calculation results of the Bishop method and M-P method had high consistency, with the maximum difference in safety factors not exceeding 0.02. Meanwhile, the order of the influence of seismic and blast vibration forces on the three profiles was B1 > A1 > C1. The calculated safety factors of the two profiles A1 and B1 obtained by the two methods were both higher than the allowable safety factor, so they are classified as stable slopes; for profile C1, the calculated safety factors under the actions of self-weight + groundwater and self-weight + groundwater + blasting vibration force were both higher than the allowable safety factor, so it is a stable slope; under the action of self-weight + groundwater + seismic force, its safety factor is slightly lower than the allowable safety factor but still greater than 1, so it is classified as a basically stable slope.

Key words: limit equilibrium method, open-pit mine, slope stability, seepage field, Bishop method, M-P method, safety factor method