Characteristics Research On Surface Potential Of Coal Containing Gas Under Loaded

This paper built the experimental system about the surface potential of coalcontaining gas under loaded process,tested the surface potential signals during coaldamaging process under different gas pressure,and analyzed the law of the signalcharacteristics.Mainly studied the relationship between potential signal and gas pressure;Tested surface potential signals under different loading way(uniaxial compression, cyclicloading, multi-stage loading);Analyzed surface potential signals characteristic rule duringcoal damaging process under different loading way; The grey-catastrophe theory that isused to analysis and treatment the potential signal of coal containing gas under loaddestruction process.The research results obtained as follows:1)Surface potential signals will be generated in the process of adsorbing gas,andthey increase gradually along with the growth of adsorption time.For the same coalsamples,different gas pressure from the coal surface potential signal to the first adsorptiongas pressure of coal potential signal has a memory effect in the process ofabsorption.When the adsorption gas pressure is higher than the first adsorption gaspressure,the coal induces stronger surface potential signals.And when the adsorption gaspressure is lower than the first adsorption gas pressure,the coal induce weaker surfacepotential signals.2)The coal containing gas can produce surface potential signal in the destructionprocess,surface potential signal and the load has a good consistency trends;For the sametype of coal samples,when gas filled0.8MPa the surface potential of containing amaximum of17mV by the destruction of coal,the stress level was75%,than coal sampleunder loaded without gas generated the surface potential four times larger and the stresslevel than without gas is small,as the gas pressure increases,the stress level of surfacepotential maximum decreases.3)Grey-catastrophe model that is used to predict and judge the instability of coalcontained gas is built according to grey theory and catastrophe theory,the result showsthat potential signal for the destruction of coal containing gas has obvious precursorcharacteristics.4)Study the surface potential mechanisms of coal containing gas under loaded,gasand stress is the result of loaded destruction.When gas is present,making the gravity ofcoal crack intramural reduced,conducive crack spread, macroscopic manifestations isdecreasing coal intensity. This study for further revealed microscopic processes of coal fracture has importanttheoretical significance.