Study On North Slope Stability Of The First Mining Area In Bai Yinhua No.2 Open-Pit

Slope stability is the premise of open-pit mine production safety.And it is especially complicated and outstanding in the soft rock slope which is influenced by the external load and has weak layer and down dip.Combining with the project conditions of the first mining area in Bai Yinhua No.2 Open-pit,this paper initially determines the potential landslide model and identifies the safety storage coefficient according to the engineering geological characteristics of the north slope.Adopting the rigid equilibrium limit method,this paper evaluates the north slope stability,optimizes the slope forms that do not conform to the requirements of the safety coefficient and calculates the stable slope angle of south north discharge field.In the same time,it also identifies the safety distance from north dump to the north of the slope when the dump field in different heights.Adopting FLAC3D,this paper establishes numerical model for both the north slope that before and after the optimization and north slope-south north dump composite slope,verifies the rigid equilibrium limit method results and reveals the spatial evolution mechanism of the slope unstability.The results show that the designed north slope is unstable,and the slope angle is between 12° and 14°.The distance between north dump and north slope is 100m,130m,and 160m separately when the height of refuse dump reaches 1200m,1220m,and 1240m.So the landslide model is cutting layer-bedding layer sliding with weak layer as the bottom boundary.