Study On Dam Break Risk Assessment And Emergency Refuge Path Of Tailings Pond Considering Downstream Loss

The tailings pond is not only an important facility for storing tailings and waste residues in mine production,but also a major threat to mine safety.As a special hydraulic structure,it may develop into a dangerous source of debris flow due to its high potential energy.Domestic tailings dam collapse accidents occur from time to time,which not only stagnates the normal production of mines,but also causes serious casualties and environmental damage to downstream areas.Although my country has carried out several special management work for various dangerous storage and dangerous storage,the number of tailings storage has decreased,but there are still more than 1,000 overhead storage storage,and the safety situation is relatively severe.Comprehensive evaluation of the dam failure risk status of the tailings pond can not only clarify the safety problems exposed in the operation of the tailings pond,but also clarify the degree of harm that the dam failure may cause downstream,which is important for improving the safety level of the tailings pond and protecting the downstream residents.life safety is of great practical significance.Therefore,this paper conducts relevant research on the risk assessment of tailings pond dam failure and emergency shelter during disasters.The main research results are as follows:(1)Through the statistical analysis of dam failure accident types,the direct and indirect causes of dam failure were clarified.According to the dam failure cause analysis and correlation analysis,17 risk indicators were determined.The four vulnerability indicators are tailings toxicity,downstream population,downstream infrastructure and downstream environmental sensitive protection targets.The indicators are integrated and classified from three aspects: natural risk,inherent risk and management risk.A tailings pond dam-break risk index system for downstream losses.(2)The improved AHP method is used to determine the subjective weights of indicators at all levels,so that the weight assignment process is optimized,and the improved EWM method is used to determine the objective weights of indicators at all levels,making the weight distribution results more reasonable.Based on the principle of minimum relative information entropy The two weights are integrated to obtain a comprehensive weight,which comprehensively considers the association between expert knowledge and experience and indicator data.Finally,combining the comprehensive weighting method with the multi-level extension evaluation method,a multi-level extension evaluation model of tailings pond dam failure risk based on the improved AHP-EWM is constructed.(3)The constructed tailings pond dam-breaking risk assessment model was applied to the Yangjiawan tailings pond,and the multi-level extension comprehensive evaluation was carried out on its dam-breaking risk state.The results showed that the dam-breaking risk state of the tailings pond was in the Between low risk and general risk,the overall risk is controllable but still needs to be paid attention to,especially the risk level corresponding to the height of the dam and the flood control standard is relatively high,and the number of people within one kilometer downstream is relatively large,in order to protect the downstream For the safety of residents’ lives,it is necessary to plan a corresponding evacuation plan to guide residents to evacuate in an orderly and safe manner during a disaster.(4)FLOW-3D software is used to simulate the overtopping dam break accident of Yangjiawan tailings pond.The simulation results show that the downstream disaster is the most serious 20 minutes after the dam break.According to the disaster scope and degree,11 disaster points are set for the downstream disaster units,3temporary avoidance difficulties are selected,and the emergency refuge topology network is constructed in combination with the downstream regional road network data.Based on Dijkstra algorithm and Arc GIS network analysis,The shortest emergency refuge path is planned for the downstream affected points.Except for the three affected points close to the dam break location,the residents of the other affected points can be safely transferred to the corresponding temporary shelters.