Research on Strata Behaviors Laws of Fully-mechanized Caving Mining at Ultra Long Working Face

In the process of fully mechanized caving mining at super long working face, because of the increase of working face length, there will be differences in strata behaviors laws of stope tendency parts. Taking 19106 working face in Pingshuo No.1 Mine as the engineering background, by using elastic and plastic theory and numerical model, the laws of mining pressure of fully mechanized caving mining are studied. The results show that the peak value of advanced abutment pressure of working face is 18.7 MPa, and the distance from the peak value to the coal wall is 16 m; the peak stress of the upper, middle and lower parts of the working face is 18.32 MPa, 18.64 MPa, 17.81 MPa respectively, and the impact range is 70 to 95 m, 75 to 100 m, 67 to 93 m respectively; at the same time, according to the damage scope and form of the plastic zone of stope roof and measured data, we can determine the first weighting step range of roof and periodic weighting step range of working face.