Study On Slope State Control Parameter Optimization And Stability Of Open-pit High Slope With Gently Inclined Weak Interlayer

In order to explore the reasonable values of bench width and bench slope angle,so as to make the mine safe and economic mining,the strength reduction method is adopted.Taking the high slope of a limestone open pit mine in Huangshan with weak interlayer as an engineering example,the slope stability coefficient calculation of different bench width and bench slope angle scheme matrix is carried out,and the influence of weak interlayer on slope stability is discussed,The optimal step width and slope angle are determined,and the linear fitting relationship between slope state control parameters and stability coefficient is revealed.At the same time,the optimization model of slope state control parameters based on SR-BP neural network is proposed to express the nonlinear mapping relationship between slope state control parameters and stability coefficient,so as to predict the slope stability under different optimization schemes of slope state control parameters.The results are as follows:(1)The results show that the relative errors of horizontal and vertical stresses of the two models are small.The number of elements and nodes of the simplified sub model are reduced by about 38%,which proves that the numerical model simplification method can effectively simplify the overall large model of high slope and quickly obtain the initial geostress field.(2)The slope stability coefficient is directly proportional to the width of the bench and inversely proportional to the slope angle of the bench.Through the collaborative optimization of bench width and bench slope angle,the optimal slope state control parameters are determined as safety platform width 4m,cleaning platform 8m and bench slope angle 64°.(3)Weak intercalation greatly reduces the stability of the slope,and is easy to become the potential sliding surface of the slope.When considering the weak intercalation,the stability coefficient of the slope is reduced by 44.8% compared with that without considering the weak intercalation.In the process of mining,real-time monitoring should be carried out.(4)The results show that the predicted values of the optimization model are consistent with the actual values,and the relative errors are controlled within 6%,MAE=0.013,RMSE=0.026,R= 0.994,with a high degree of agreement.The results show that the model is reasonable and reliable.The research results provide a certain guidance for mine safety and economic production and reasonable design,and provide a new idea for rapid generation of initial geostress of high slope integral large model.