Correlation Analysis Of Gas Parameters And Seismic Parameters In Mine

The economic development of coal is seriously threatened by the mine accidents,especially by coal and gas outburst. Currently gas desorption index K1, drill cuttings S andother calibration parameters were used to evaluate the coal and gas outburst. Traditionalmethods have some trouble in fast and convenient judgement. Rapid assessment of seismicattributes for mine coal and gas outburst is a necessary way to solve the problem.Based on the theory of kinematics and dynamics, combined with elastic andnon-elastic properties characteristic of outburst coal, establish a physical model relate tothe coal and gas outburst mechanism indoor. Obtain elastic parameters, speed andnon-elastic parameters of the model by uniaxial compressive tests and seismic tests.Numerical simulations were establishded to make sure the methods to get quality factorwere stability. Combined the results indoor, build the correlation between the mine seismicattribute and gas parameters, analyze the relationship between the different observingsystems under various parameters.In different mines, coal with lower velocity and higher Poisson ratio, theconcentration of gas appear to be higher, and it’s more likely to occur coal and gasoutburst, while the lower elastic modulus of coal. Compared to other observing systems，velocity acquired by Seismic Computed Tomography have better relationship with gasconcentration, shear wave velocity Vs and gas concentration linear fit of R2≈0.82. Gasconcentration, K1and decay coefficient values showed a positive correlation between thedegree of linear fit0.81≤R2≤0.94, and also showed a negative correlation with qualityfactor Q between the degree of linear fit0.57≤R2≤0.76. Compared to the amplitudedecay method, spectral ratio method is more accurate to strike a quality factor. Dynamicelastic modulus Ed, shear modulus G showed a positive correlation with coal ruggednesscoefficient of linear fit of R2≈0.71. Seismic frequency fmaxshowed a negative correlationwith drill cuttings, gas concentration, K1values respectively the degree of linearcorrelation R2≈0.95,0.74,0.71; Drill Seismic Detection frequency showed advantage inobtaining coal main frequency. In the case of Yangmei Company, coal that have morepossibilities to occur an outburst may have features such as:1. Shear wave velocity Vs≤0.63m/ms and Vp/Vs≥1.87;2. Dynamic elastic modulus Ed≤2Gpa and shear modulusG≤1Gpa;3. Decay coefficient values α≥0.7×10-3and quality factor Q≤3.Obtain correlation between mine seismic parameters and gas attributes through methods mentioned above, the study still needs further development and testing.