Stability Analysis Of Goaf And Pillar And Study On The Monitoring Scheme Of Ground Pressure In Nandangchang Mine

With the frequent occurrence of mine ground pressure disasters in China,the management of goaf and ground pressure control is becoming more and more important to the safe production of mine.In this paper,based on the research on the monitoring and prediction of the goaf and pillar ground pressure in the middle section of 1000 m and above in Nandang Factory Mine.In view of the current situation of the mine,the field investigation and test are carried out,and the stability of the goaf and pillar is analyzed with FLAC3 D software.Considering the comprehensive consideration,the plan for monitoring and predicting ground pressure has been worked out,which plays an early warning role for ground pressure activities and is of great significance for underground safety production.This research mainly carried out the following aspects:(1)A series of investigations and experiments were carried out,including the engineering geological survey,rock physical,mechanical tests within the scope of the study and the quality of rock mass was graded and evaluated by RQD,Q,RMR and BQ system respectively,which provided a theoretical basis for the follow-up study.(2)Considering that the pre processing function of numerical calculation software FLAC3 D is not perfect,it is difficult to build complex 3D models.The Auto CAD is used to draw the line frame model of the ore body,and imported into the three dimensional mining software3 DMine for model visualization processing.Finally,the three dimensional model is introduced into the MIDAS GTS to divide the grid,and the ore body mesh model is obtained.Then the grid model is introduced into FLAC3 D by using the coupling function of MIDAS GTS and FLAC3 D,and the model construction of the underground complex goaf area in FLAC3 D is realized.The reliability of the model is analyzed and proved,and the stability of goaf and pillar in the model is analyzed.The simulation results are consistent with the current situation of the mine.On this basis,the variation of stress field,displacement field and plastic zonedistribution after filling in some goaf is simulated,and it is demonstrated that filling goaf can effectively improve the stress concentration and plastic damage.(3)Studing the current domestic and foreign pressure monitoring methods,combined with the results of the stability analysis of the goaf and pillar in the middle section of 1000 m and above in Nandang Factory Mine.A real-time on-line monitoring system for multi-channel acoustic emission is established by choosing a reasonable ground pressure monitoring and prediction scheme.According to the selected monitoring scheme,the rational monitoring instruments and monitoring techniques are selected to provide technical and scientific support for the mining of the residual ore in the middle section of 1000 m and above and the safe construction and ore recovery in the deep exploration project.