Application Study Of Sound Wave Detection Technology In Stability Analysis Of Goaf In Shilei Tungsten Mine

The stability of mine goaf is one of the main safety issues in mines.In this paper,taking the stability analysis of the goaf of Shilei tungsten mine as the research background,the rock mass acoustic wave detection technology is used to perform the indoor rock sample wave velocity test on the surrounding rock of the mine goaf,and the wave velocity change of the rock sample is recorded under the uniaxial loading condition.At the same time,the singlehole one-shot double-receiving rock mass acoustic wave test method was used to conduct on-site acoustic wave testing of the ore pillars near the V69 and V70 veins in the 525 middle section,475 middle section,418 middle section and 378 middle section of the northern zone of the mine.The mesopore depth-wave velocity curve diagram further analyzes the location of the rock mass loosening circle.According to the waveform collected by the on-site detection of the sonic instrument,the degree of crack development in the rock mass is analyzed.Finally,a comprehensive analysis is carried out based on the monitoring results of the displacement of the surrounding rock and the cross section of the goaf monitored by the photoelastic stress gauge and the convergence instrument.The study found that the sound wave detection technology can accurately understand the stability of the goaf in the tungsten mine.(1)By studying the elastic properties of rock masses and the propagation characteristics of sound waves,understand the physical and mechanical properties of rock masses,the degree of weathering,structural planes and the pressure and temperature of rock masses on the propagation of elastic waves,and use statistical characteristics to study them Existing laws,so as to grasp the correlation between the elastic wave propagation characteristics in rock mass and its physical and mechanical properties.(2)The parameters such as the size,density and uniaxial compressive strength of the core specimen are measured.According to the linear fitting of the density of the core sample and the wave velocity of the core sample,there is a good linear relationship between the core sample and the core sample wave velocity.If the core sample density is high,the wave velocity corresponding to the core sample is also large.It can be seen from the joint test of uniaxial loading and acoustic wave on the core specimen that the wave velocity of the core specimen increases significantly with the increase of pressure during the entire uniaxial loading process,and then enters a gentle phase.According to the relationship between the pressure on the core specimen and the change of wave speed,it can provide a basis for judging the surrounding rock loose circle.(3)Using sound wave detection technology,a large-scale loosening ring test can be carried out on mines.The test rock mass loosening ring can reflect the stability of the rock mass.In this chapter,the acoustic wave test is performed on each middle section of the northern zone of the mine with a sonic instrument and double-receiving device,and the wave velocity-hole depth curve is drawn according to the test results,so as to determine the thickness of the loose ring and the destruction position of the ore pillar where each middle section is measured.According to the comparison of the acoustic wave test waveform chart and its spectrum analysis chart of the ore pillar and the complete rock sample waveform chart,the development degree and damage degree of the joint cracks inside the ore pillar are judged.Combined with the current measures for the control of the mined-out area of the mine,it can be shown that the measures for the control of the mined-out area of the mine are effective.(4)Select suitable monitoring points in the mines under study,survey the ground pressure around the monitoring points on site,and use photoelastic stress gauges and convergence instruments to monitor the displacement of the surrounding rocks and roadway sections in the goaf for long-term monitoring.According to the monitoring results,the stability and displacement of the surrounding rock in the goaf are analyzed.Therefore,the stability of the goaf is comprehensively analyzed with the on-site sound wave test results.