Study On Dynamic Response And Instability Control Of Longitudinal Filling Goaf Group

In the process of underground mining of mineral resources,there will be a large number of goaf groups.In order to eliminate all kinds of safety hazards caused by goaf group,the filling technology is usually adopted by the mine,forming a filling goaf group.The filling goaf group is affected by complex static load and the blasting disturbance load produced in the production process.If the external disturbance load exceeds the bearing capacity of the filling body,it is likely to lose its self bearing capacity and lead to the overall instability of the filling goaf group.Therefore,it is of great significance to study the dynamic response and instability control of the filling goaf group to ensure the safe production of the mine.Based on the field investigation,this paper takes a longitudinal filling goaf group in a tungsten tin metal mine as the research object,uses the methods of theoretical analysis,numerical simulation,displacement monitoring and engineering practice to study the stability of the system of longitudinal filling goaf group under the disturbance of blasting load,and puts forward the engineering control method of weakening blasting disturbance.The main work is as follows.(1)Based on the detailed investigation of the goaf,the distribution and storage environment of the filling goaf are mastered,and the stability factors and main control factors affecting the filling goaf are analyzed.(2)The dynamic response model of the longitudinal filling goaf group is established.The reliability of the model is verified by comparing the numerical simulation and field monitoring data with the calculation results of the dynamic model.The attenuation law of the dynamic response of the filling goaf group under the disturbance of blasting load is studied.The results show that the vibration transmission of the filling goaf group has a delay,and the vibration frequency of the filling body decays fastest.(3)With the help of numerical simulation software and dynamic model,the stability of the longitudinal filling goaf group under different working conditions is analyzed from the dynamic and static angles.After the recovery of the ore body in the middle part of the lower part and the balance of the stress redistribution,when the proportion of the filling roof is 1: 2,the filling goaf group is in a stable state;when the proportion of the filling roof is 1: 4,thefilling goaf group is in a critical state;when the proportion of the filling roof is 1: 6,the filling goaf group is in a unstable state.(4)The engineering control method of filling goaf to weaken the blasting disturbance is studied,and the control measures of weakening the blasting disturbance from the aspects of single section blasting charge,millisecond blasting and filling body strength control is put forward.The research results can provide theoretical reference for stability analysis,instability control method,reduction of production cost,recovery rate of mineral resources and improvement of intrinsic safety level of longitudinal filling goaf group under blasting disturbance,and have engineering application value.