Study On Ground Pressure Monitoring And Forecast Technique Of The Mined-out Areas In Dong He Wan Iron Mine

The Donghewan iron mine puts into production since2001, it always used the open field methodwhich is simple and low cost. The mine has been mining for ten years. here are many bulky and longexposure time mined-out areas, there is always the possibility of collapse, they caused many insecurityelements of the mining production activities. In order to avoid the disasters and accidents of pressuredisasters, we used the advanced equipments and means to monitor the activities of the pressure ofmined-out areas and grasp the dynamic activity patterns of the surrounding rock of mined-out areas,established the forecasting and early warning system is an urgent subject of the mine.In this study, we based on the site survey, combined the rock physical and mechanical tests androck burst acoustic emission test,. We tested the physical and mechanical characteristics of the rock inthe mine and got the acoustic emission parameters information of the rock in the force-deformationprocess, provided the reference data of the analysis for forecasting the instability of the broken rock.On the basis of the test, with the MIDAS/GTS that is rock mechanics analysis and calculationsoftware, built the3D geomechanical model of the underground mining of the Donghewan mine. Weanalyzed the characteristics of the rock on the three mining levels (+20m,-85m and-130m).According to the simulation results, the stress and strain of the rock in-85m level and-130m level arelarge, the areas of stress concentration are large. These areas formed the superimposed effect of spaceon the up and down levels, these areas easily collapse and form the pressure disasters of the mined-outareas. They are the sensitive areas of the underground pressure in the mine. We made sure that theyare the areas of focused on monitoring.According to the results of the simulation analysis, we used the STL-12multi-channel acousticemission monitoring system and established the pressure monitoring system for this mine. With thissystem, we realized the all-weather and online monitoring of the pressure and real-time access to theacoustic emission information of the rock. We grasp the rock pressure active of the mined-out areas.Combined with the results of laboratory tests, through the filtering processing and data analysis, wemade a database of waveform and acoustic emission parameters, put forward the evaluation of mined-out areas and the warning and forecast system of underground pressure. According to the nearly a yearmonitoring data, we evaluate the stability of the Donghewan mined-out areas.Through the monitoring and analysis pressure of the Donghewan iron mine mined-out areas,there is a reference for pressure monitoring of other mine mined-out areas.