Study On The Instability Law Of Surrounding Rock In Goaf Of Self-propelled Iron Mine Based On Acoustic Emission Monitoring Technology

Now,some domestic mining relatively long time mines are left big goaf,the mined out area due to the influence of stress concentration,rock weathering,blasting mining and other factors,there appeared many help even piece roof fall,rock burst and other geological disasters,seriously affect the safe production of mines.Is one of the most dangerous source in the mine.The Ludian mineral company since go iron ore pressure monitoring project as the background,the 1530 middle and 1580 middle part of goaf surrounding rock instability were analyzed.The paper combines field investigation,laboratory test,numerical simulation and theoretical calculation,programming calculation,theoretical analysis and other research methods,found some laws of surrounding rock stability,engineering monitoring,prediction of mine has practical significance for the timely processing of goaf and surrounding rock instability state.The main contents and results are as follows:1、On the middle of the iron ore 1530,the 1580 section of the mined out area,especially the 1530 stratification and the 1580 stratification,field investigation,to the master of the mine to consult and collect relevant geological data.At the same time,it enriches the knowledge of AE,the application of acoustic emission technology in rock mechanics,summarizes the research status at home and abroad,and discusses the significance of the research.2、The design of indoor test plan,launch test of limestone acoustic uniaxial compression,the experimental data were processed and analyzed on the part of the acoustic emission parameters,provide the basic data for the later analysis of fractal theory.3、Using FLAC3D to simulate the mined out area of 1530 middle and middle section of 1580.In the process of simulation,the problem of calculation is taken into account.The results of maximum principal stress distribution,the minimum principal stress distribution,plastic zone distribution and displacement;and theoretical calculation of goaf surrounding rock pressure;make analysis according to these results,the acoustic emission location sensor optimization.4、The parameters collected in the experiment and engineering monitoring are mainly stress and ringing count,and the fractal dimension is calculated by matlab.According to the above,it is concluded that the failure of rock mass in the rock specimen or in the engineering is a process of dimensionality reduction.The continuous dimension reduction process is the process of the formation of large fracture surface.5、By analyzing the monitoring data in practical engineering,the fractal dimension D=1.22 is used as an early warning value of the surrounding rock instability.And the application of the conclusion and the existing software for the monitoring and analysis of the surrounding rock of mined out area.