| The study on slope stability is a long-term research which relates to production safety and continuous operation of open pit mine.Open pit mining of metal mines occupies a considerable proportion in China,many of which sufer from the impact of slope instability.Through slope stability analysis and monitoring data prediction,timely grasp the trend of slope displacement and predict the imminent damage,take appropriate treatments to avoid unnecessary losses.Wushan Copper and Molybdenum Mine is located in the north of Inner Mongolia.With the expansion of exposed rock mass,the abundance of joint structure in different area varies greatly.Abundant structure and fractured rock mass have caused a certain impact on the safety production of lower part.It is in an urgent need to evaluate the slope stability,so as to formulate an economic and reasonable monitoring and governance scheme.At present,there are the following problems in slope stability evaluation:(1)The qualitative evaluation represented by engineering geological analogy have some limitations on the deep geological conditions of the slope and the mechanical relations among the structures;(2)As a quantitative evaluation method,numerical simulation needs a model which takes a long time to build,and large-scale numerical calculation requires high calculation capacity;(3)The state of the slope at the present stage are mainly analyzed from the displacement-depth curve,however,the prediction and analysis of displacement-time data are the key of slope early-warning.Considering the problems above,this article takes Wushan copper molybdenum mine as an example,a quantitative-qualitative-prediction study on the slope stability was taken.works such as tilt UAV photogrammetry,landslides susceptibility mapping,the deployment of monitoring equipment,the numerical simulation of slope,displacementdepth curve analysis and displacement-time curve prediction is carried out,and the result was uploaded to the cloud platform,the main achievements of this thesis are described as follows:(1)Based on the aerial disciplines,the UAV photogrammetry technology was applied.,DJI software was used to establish a three-dimensional model combining camera parameters,image data and POS data.(2)Selecting several factors which affect the slope stability,landslide susceptibility mapping generated by information volume and optimized by gradient boosting decision tree was used as qualitative analysis method.The natural breakpoint method was used to partition the map of landslide susceptibility and locate the dangerous areas.(3)Based on landslide susceptibility map and the importance of the slope,the monitoring scheme is formulated according to the basic indexes of slope safety monitoring.(4)Based on the landslide susceptibility map,some slopes with high landslide risk were selected,and a new modeling method based on UAV tilt photogrammetry was used to carry out numerical simulation.At the same time,the displacement-depth curve is analyzed to judge the slope stability at the present stage.(5)Using the long-short time memory neural network,the displacement-time curve of abnormal displacement is predicted,however,it is difficult to predict the displacement mutation.Slope of open-pit mine is a complicate system affected by many factors,rainfall data was added for displacement predicting using nonlinear autoregressive neural network with exogenous input.As the prediction result shows,adding rainfall data can improve the accuracy of prediction.According to the relationship between rainfall and tangent Angle of slope displacement,the slope displacement warning threshold based on rainfall is given. |
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