Safety Mining Evaluation of Goaf Water on the First Mining Face of No.15 Coal Seam in Tongbao Mine
To ensure the safe mining on the first mining face 15105 of Tongbao Mine,this pa-per uses different calculation methods to analyze the height of the water-conducting fissure zone,the thickness of the protective layer,and the destruction depth of No.3 coal seam floor;then combined with the numerical simulation,it evaluates the impact of goaf water above the first min-ing face 15105 on the safety of the first mining face.The results show that,within the working face 15105,the difference value between the coal spacing and the height of the waterproof coal pillar is greater than 0,in other words,the coal spacing is greater than the height of the water-proof coal rock pillar.FLAC3D numerical simulation shows that without other water-conducting channels such as tectonic structures,the water-conducting fracture zone multiplied by the first stage of the first mining face 15105 does not connect to the goaf water in No.3 coal seam.