| The stability evaluation of open pit slopes has always been an important component of open pit mine research.In the production stage of open pit mines,with the development of mining engineering,more and more strata are exposed,and more and more accurate structural surface information can be obtained in a larger scope and more space,and the new ones are grasped.The structural surface information is used to evaluate the stability of the rock mass of the mine slope engineering,and according to the evaluation results,the boundary or slope angle of the original design of the open pit mine is appropriately adjusted,and the optimal slope angle is designed to meet the requirements of“economical and safe”.The principle of"to achieve the best overall economic benefits of open pit mines.According to statistics,the instability of the slopes of large-scale open pit mines in China mainly occurs in step slopes or combined step slopes.The general slope is safe,the step slope or the combined step slope is unsafe.This ubiquitous fact It shows that the traditional method of evaluating the stability of different grades of slopes with the same design safety factor standard needs to be improved.Therefore,Du Shigui proposed a new set of slope stability evaluation methods for large-scale open pit mines in the?Methods for Accuracy Evaluation of Slope Stability of Large Open-pit Mines?[1],and the method was popularized and applied in a large number of open pit mines.This paper takes the eastern slope of Dapingzhang Copper Mine as the research object,analyzes the stability of the eastern slope by using the accuracy evaluation method and finite element method of large open pit mine slope,and draws the following conclusions:?1?Based on the components and scale of the large open pit slope,the slope can be divided into three levels:the overall slope,the combined step slope and the step slope;according to the geometric relationship between the structural plane scale and the scale of each level of slope,The structural plane is divided into three levels:the through-structure plane,the non-penetrating structural plane,and the small-scale structural plane.Because of the difference in the influence of different spatial locations and different scale structures on the rock mass stability of different grades of slopes,In the slope stability evaluation,the matching relationship between the spatial position of the structural plane and the slope location,the matching relationship between the structural plane scale and the slope scale are considered.?2?Based on the stratified analysis of the spatial position,size and slope matching relationship of the structural plane,a hierarchical analysis method for systematically evaluating the stability of large-scale open pit slope rock mass engineering is proposed.According to the matching of the spatial position of the structural plane with the slope location,the matching of the structural plane scale and the slope scale,the overall stability analysis and localization of the III overall slope,combined step slope and step slope of the large open pit mine are carried out hierarchically.Stability analysis.The potential slip surface determined by the grading analysis and its potential slip direction can be used to accurately and accurately determine the shear strength of the rock mass structure surface of the large open pit mine.The potential damage model determined by the grading analysis can be large.The accuracy evaluation of rock mass stability of open pit mine provides an objective and realistic calculation model.?3?According to the results of slope stability analysis,the potential slip surface is determined and the potential sliding direction is determined.The structural surface geometry is used to record the structural surface geometry,based on morphological filtering denoising,image normalization method and global search method.Calculate and statistically analyze the roughness coefficient of the surface profile curve of the structural surface;determine the stability threshold of the structural surface roughness coefficient according to the variation law of the structural surface roughness coefficient;and use the rebounder to measure the rebound value of the rock mass strength of the rock mass.Furthermore,the rock wall strength value and residual friction angle of the rock mass are obtained.When the structural surface size reaches the stability threshold,the structural surface roughness coefficient and the wall rock strength value are calculated.The shear strength parameters of the rock mass structural surface are obtained by linear regression method.?4?Based on the accuracy evaluation method of large-scale open pit mine slope,the three slopes of the slope,the combined step slope and the step slope are analyzed to obtain the overall slope of the eastern slope of the Dapingzhang copper mine.,combination of step slope,step slope stability.?5?The 2D finite element model was established by using MIDAS-GTS,and the stability of the slope slope of the eastern slope was calculated and analyzed.And compared with the results obtained by the equal accuracy evaluation method.?6?The 3D finite element model was established by using MIDAS-GTS to calculate the stability of the eastern slope on the overall slope under normal water level and rainfall conditions. |
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