Determination and Application of Rational Supporting Strength for Supports in Large Mining Height Fully-mechanized Working Face

To study the reasonable support strength of fully mechanized caving face supports in shallow coal seam and analyze mine pressure characteristics of working face, taking 12301 working face of Shendong Mine as an example, the types of roof of working face is determined, and according to the maximum mining height of the working face, the bearing load of the support and the dynamic load, the supporting strength of the supporting and sheltering support of the selected type of ZY11000/25/50 is analyzed by theoretical calculation. Research shows that: the statistical qualification rate of the supported shield support used in the working face is 62.8%, and the overall utilization ratio of initial supporting force of support is high. This type of support can be used to support the roof completely. The average initial caving step distance of the direct top was 12.78 m, the average initial pressure step distance of the basic top was 66.88 m; in the whole working face, the maximum and the minimum periodic weighting seeps of basic roof is 67.1 m and 11.8 m respectively, and the average periodic weighting length is 32.5 m, and the strength is moderate. The average strength of basic top pressure of 12301 face is 30.0 MPa. It is determined that the support can adapt to the working face roof movement law.