Abstract: The “three zones” height of mining overburden roof strata of fully mechanized working face 68303 in Du’erping coal mine have been studied by similar simulation experimental method based on the overburden rock mass failure properties and the characteristics of fractures distribution and development. The heights of caved zone, fractured zone and continuous deformation zone are 12.5 m, 37.5 m and larger than 80 m respectively by research of gob roof strata fracture, separation and convergence, distribution and extension of fractures. The experimental results are compared to the in-situ measurements of upward inclined holes water injection and the flow parameters. The heights of caved and fractured zone differ by 0.8 m and 2.5 m respectively from the in-situ measurements. The results show that the similar simulation experimental study based on the characteristics of fractures distribution are reasonable and reliable, which can be used as effective means for the research on overburden roof strata “three zones” height of working face.

Key words: "three zones", height；similar simulation；fracture distribution；in-situ measurement