Mechanism and control of large deformation of coal wall in fully mechanized top-coal caving face with weak interlayer

Large deformation often occurs in the coal wall with weak interlayer, which affects the normal use of the roadway. Based on the research background of the track channel of 3308 working face in Dongtan Coal Mine, the large deformation characteristics of the side of the roadway with weak interlayer are analyzed by means of field measurement, numerical simulation and theoretical analysis, and its instability mechanism is studied. The criterion expression of the shear failure of the coal pillar is obtained, and the influence law of the surrounding rock mechanical parameters on the large deformation is discussed. The results show that the peak value of the horizontal displacement of the two sides is at the weak interlayer, which is the key factor for the large deformation of the coal side; the axial tension produced by the large deformation of the coal wall with weak interlayer on the anchor rod is insufficient to destroy the anchor rod (cable) body. The loss of the bearing capacity of the anchor rod (cable) may b