Risk Analysis of Coal and Gas in Multi Coal Seam Geolo-gy of Tongzi Tunnel
To investigate the risk of coal and gas outburst in the Tongzi Tunnel crossing coal seams,parameter wells were arranged to identify the geological strata,structures,coal seams,and coal-bed methane reservoir characteristics in the tunnel area.The analy-sis results show that there are a total of 7 coal seams encountered during drilling,including 4 with a thickness greater than 0.3 m.The coal type is lean coal,and the C3 and C6 coal seams have ex-plosive coal dust.The gas content near the coal seam tunnel is 3.10-11.29 m3/t.The gas pressure of the C3,C5,C6,and C7 coal seams is all greater than 1.0 MPa,and the initial velocity of gas release is all greater than 10 mmHg.The C3,C5,C6,and C7 coal seams have a risk of coal and gas outburst.The drilling analysis results provide reference and inspiration for similar projects in the region.
Highway tunnelCoal and gasParameter wellUn-covering coal
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