Research On The Rockburst Induced Tendency And Optimization Of Stope Structure Parameters In A Copper Mine

This paper mainly researches mining in a copper mine.Multi index comprehensive evaluation of rock burst tendency of representative rock in mining area was carried out,different rock burst proneness of rock failure before the acoustic emission characteristics was analysed and deep stope structure parameters and strength distribution of filling body were optimized by using the means of field investigation,field sampling,laboratory experiments,theoretical analysis and numerical simulation.The contents and achievements of research mainly include:?1?The rock core of representative rock which choosed by consulting the geological data of mine was extracted from the mining area and tested in chamber to obtain their elastic energy index“W_ET”,uniaxial compression strength,tensile strength and modulus of elasticity,at the same time,the acoustic emission signals of different rocks in the process of uniaxial loading to failure were collected.?2?The rockburst tendency of each rock was determined comprehensively by using improved grey evaluation model according to rock burst tendency index,such as elastic energy index“W_ET”,maximum elastic strain energy index“E_S”and rock brittleness coefficient“K”.The results show that the black mica granodiorite,the biotite quartz schist and the medium fine two granites are medium rock burst rocks,and carbonaceous mica quartz schist is a strong rock burst rock.?3?The acoustic emission characteristics of different rock burst tendentious rock before failure were obtained by studying the energy rate of acoustic emission,the rate of acoustic emission events and the number of cumulative acoustic emission events of the acoustic emission signals were collected during the uniaxial compression test.It was concluded that rocks with strong rockburst tendency entered the quiet period of acoustic emission earlier and lasted longer than those of medium rockburst tendency,at the same time,we found that a large number of acoustic emission events which have small energy occurred at the initial stage of loading,but there was a small amount of acoustic emission events which have large energy near the destruction stage in all rock samples.?4?Combining the investigation of the ground pressure in the various stages of the mining area and determination result of rockburst tendency,the reasonable exposed area of the roof and the strength distribution of filling body in the 1330 meter stage were simulated and calculated by building the whole model of mining area through the numerical software FLAC3D.The reasonable structure parameters and strength distribution of filling body in the 1330 meter stage were obtained by analysing and comparing the distribution of stress,the risk of rockburst,the displacement and the distribution of the plastic zone in the stope.The reasonable exposed area of the 1330 meter stage is 250m³,and the strength distribution of filling body is that the cement sand ratio of 20meters at the bottom is 1:4,while the cement sand ratio of 20 meters in the middle is 1:8,the top 20meters is the same as the bottom 20 meters.