With the increasing intensity of coal mining and the increasing area of goaf,the detection and determination of the"two-zone"height is more and more important for the safe and efficient production of coal mines.A variety of methods such as drilling flush-ing fluid leakage observation,drilling water level observation,abnormal drilling phenomena observation,color drilling TV observation were used to detect the damage of overlying rock in 5-2 coal seam of Qinglongsi Coal Mine.The comprehensive analysis determined that the maximum caving zone height of 5-2 coal seam fully-mechanized mining face in Qinglongsi Coal Mine was 17.0 m,the caving ratio was 7.4,the maximum water conducted zone height was 46.87 m,and the cracking ratio was 20.4.At the same time,the rock mechani-cal properties of the overlying rock of the 5-2 coal seam were tested and analyzed.The lithology of the overlying rock of the roof was di-vided into two categories:sandstone rock layers and mudstone rock layers.In the range of 70 m above the roof,the sandstone rock layers accounted for 96.14％.The average uniaxial compressive strength under natural conditions was 67.82 MPa.The overlying rock belongs to hard type and have the characteristics of hard roof.The results of this detection and mechanical analysis provide technical reference for the subsequent upward mining of Qinglongsi Coal Mine.
"two-zone"heightdrilling flushing fluidleakage quantitycolor TV observationrock mechanics test
NETL
NSTL
万方数据
