Construction And Application Of Risk Assessment Model For High Slope In Open-pit Coal Mine

In this dissertation,the risk factors of high slope in open-pit coal mine are identified and refined,and the risk management system of high slope is established based on the characteristics of the analysis system of critical control points in high slope risk management of open-pit coal mine.By setting up the monitoring procedure and rectifying measures of the critical control point management system,it provides theoretical support for the risk early warning,monitoring and control of the key control point of high slope.Secondly,the evaluation system of high slope risk factors is composed of four primary indexes including hydroclimatic conditions,geological structure of slope,slope geometric conditions,induced factors and 17 secondary indexes which are weathering and freezing/thawing conditions,groundwater occurrence,permeability of rock and soil layer,annual average rainfall,lithology,geological structure,slope structure,internal friction angle,cohesion,slope angle,slope height,weak surface(layer)and slope relationship,slope shape,human factors,blasting effect,excavation slope angle and seismic intensity.Thirdly,through the mixed evaluation method,the risk factors in the critical control point risk evaluation system of high slope in open pit coal mine are solved,which have both qualitative and quantitative characteristics.The quantitative analysis of high slope risk factors in open pit coal mine has improved the adaptability and ease of use of the critical control point risk assessment model in high slope risk management of open pit coal mine.Through research,the mixed evaluation has the advantages of strong adaptability,but there is a problem of inaccuracy of risk assessment.Because of the insufficiency of mixed evaluation,this dissertation studies the unstable extension evaluation model to improve the evaluation accuracy of high slope risk model in open pit coal mine.According to the characteristics of high slope risk management system in open pit coal mine,the extension-AHP evaluation method is improved by two-interval set of uncertain correlation function,and the extension risk evaluation model is optimized.The uncertain extension risk evaluation method is established by the combination of extension and AHP.This method not only reduces the interference of human factors in risk assessment,but also has high precision in calculating the correlation between risk factors and evaluation results.It is suitable for the early warning management of high slope in open pit coal mine at present.However,it is found that the extension risk assessment has the disadvantage of insufficient data integration ability for high slope of open-pit coal mine.In order to strengthen the reasonable determination of index weight and the effectiveness of the integrated algorithm,this dissertation improves the interval intuitionistic fuzzy entropy risk assessment method.Aiming at the inadaptability of interval intuitionistic fuzzy number to the risk factors of high slope in open pit coal mine,a new axiomatic definition of interval intuitionistic fuzzy entropy and its entropy formula are studied and deduced,and then the distance formula of interval intuitionistic fuzzy number is given,and the related algorithm is applied to interval intuitionistic fuzzy entropy-based risk assessment model for high slope in open pit mines.By using interval intuitionistic fuzzy entropy,the weight of each index factor influencing the high slope risk of open pit mine is calculated,which can effectively avoid the influence of human factors.Interval intuitionistic fuzzy entropy risk assessment model has strong objective evaluation ability,which can make the evaluator judge the monitoring data of open pit coal mine effectively.It not only enhances the information of the data,but also is easy to program.However,the model is not sensitive to the evaluation time range and cannot reflect the effect of change for the high slope over time of open pit coal mine completely.In order to improve the accuracy and comprehensiveness of risk assessment of high slope in open pit coal mine,a dynamic interval trapezoidal fuzzy soft set model for risk assessment of high slope in open pit coal mine is established through in-depth study of soft set model.Firstly,the definition of the improved interval trapezoidal fuzzy soft set is given on the basis of the study of the soft set,the operation properties are given,the related theorems such as interval trapezoidal fuzzy soft set are discussed,and the proof process is given.Secondly,by analysing the existing entropy weight method,the interval trapezoidal fuzzy entropy formula is constructed and used to determine the weight of monitoring data in different time intervals.Finally,according to the FAHP method to solve the weight of the parameters in the influencing factors,a dynamic risk assessment model of open pit high slope based on interval trapezoidal fuzzy soft set is established.Interval trapezoidal fuzzy soft set evaluation can be used to evaluate the risk of high slope in open pit coal mine at different time points,and realize dynamic early warning of high slope risk in open pit coal mine.The risk factors of Shenhua Baorixile Open-pit Coal Mine slope are evaluated by extension evaluation model.The interval intuitionistic fuzzy entropy evaluation model and interval trapezoidal fuzzy soft set model are used to evaluate Shenhua Beidianhengli Open-pit Coal Mine high slope.The validity of the model is verified.Through the practical application of the evaluation,the influence weights and evaluation results of high slope risk factors affecting Shenhua Baorixile and Shenhua Beidianhengli Open-pit Coal Mine are confirmed.For the risk factors which have a great influence on the slope,the slope instability analysis,slope stress monitoring,water inrush drilling test and seepage law research are carried out in Shenhua Beidianshengli Open-pit Mine.The numerical model of water inrush effect on the inner dumping slope is established and the current slope is analysed.The risk situation confirms the scientific and effectiveness of the evaluation model.Finally,this dissertation establishes a high slope risk assessment system of open pit coal mine based on critical control points.By using extension,interval intuitionistic fuzzy entropy and interval trapezoidal fuzzy soft set model,the high slope risk of open pit coal mine is analysed and evaluated comprehensively and accurately,and the quantitative dynamic risk assessment of high slope of open pit coal mine is established.According to the results of the evaluation,the validity of the model is verified.The protection measures for the identified high-risk factors are formulated to ensure the safety and control of the risks.