| The mined out area is a significant security risk for underground mine,the ground pressure disaster caused by the instability of mined out area not only threatens the production safety,but also affects the recovery of ore resources.In this paper,the problems of stability analysis and recovery of residual ore of middle segment goaf in Making iron mine is taken as the research background,the status and stability condition of mined out area is studied,and its evaluation results is gotten through the methods of field investigation,theoretical analysis and numerical simulation,then the suggestions of the goaf governance and residual ore recovery are put forward.The main research carried out as follows:(1)Analyzing the geological and hydrogeological characteristics,distribution condition,geometric parameters and spatial shape of mined out area,mastering the goaf distribution status and engineering environment by field investigation and research on goaf existing drawings and data.Besides,the factors that affect the stability of mined out area are analyzed and summarized,which makes a preparation for theoretical analysis.(2)Using the AHP method to establish the analytic hierarchy model,the factors affecting the stability of mined out area are analyzed by single and multiple levels,and the influence factor weight ranking is obtained.Based on which main influence factors are selected,the evaluation index system is constructed by FCE method,and the fuzzy mathematical model was established.Then the two level fuzzy comprehensive evaluation is carried out,and the results of the stability classification of the mined out area were obtained.(3)Numerical simulation from two aspects of static analysis and dynamic analysis is carried out by using ANSYS,a finite element numerical calculation program.The stability of mined out area was obtained through analyzing the stress field,displacement and plastic zone distribution of surrounding rock before and after excavation;besides,the influence of blasting vibration on the stability of mined out area is simulated.Then this method is applied to mined out areas of four section,compare the result of which with the fuzzy comprehensive evaluation method,getting the final comprehensive evaluation results of the stability of mined out areas.(4)On the basis of the above research results,the goafs are divided into A,B,C three categories,accordingly,classification management method and suggestion of residual ore mining safety are put forward.Taking typical goaf as an example,specific scheme is made for pillar mining and goaf treatment,and verified its feasibility in technology and economy. |
PDF Full Text Request