To ensure the safety and efficiency of mining in soft and low permeability fiat coal seam with high gas content, we take the X10901 working face in Dawan mine west shaft as the studying object, and study on stress change law, overburden damage and deformation distribution law of the protected seam during mining of upper protective seam using FLAC3D , and carry out the inspection certification of protective effect on site. The results show that the overburden around the stope has experienced a transformation from initial stress area to stress concentrated area, depressurized area, stable area and new compaction area in the whole process of excavation. With the advance of working face, the depressurized area formed by upper protective seam mining gradually enlarges from ＂V＂ type to ＂U＂ type. After the protective seam mining, the amount of maximum swelling deformation of protected seam can be 12. 2mm （ the relative swelling deformation is 4. 52%~）, and the distribution of ＂three zones＂ and floor heave of overburden is formed in the vertical direction. Combining with the field observation of protective effect, protected coal mass has been fully protected with upper protective seam mining. All of these has not only almost eliminated coal and gas outburst danger, but also provided a strong foundation for the high yield and high efficiency of coal mine.
flat coal seam
upper protective layer
soft and low permeability coal seam