Study on deformation law of surrounding rock in gob-side entry retaining formed by roof fracturing

This paper takes the mining face of Hongjingta No.1 Coal Mine as the research object, based on the technical principle of non-pillar gob-side entry retaining formed automatic by roof fracturing and pressure releasing, by means of numerical simulation and field measurement, the distribution of the supporting pressure of roadway surrounding rock and the deformation law of surrounding rock in the roadway were analyzed.The research results show that: with the advance of the working face, the supporting pressure of roadway surrounding rock increases first, then decreases and finally tends to be stable, and the stable value of the supporting pressure is 13.5 MPa; under the influence of dynamic pressure of working face mining, within 70 m distance of the working face, the anchor cable force increases sharply to the constant resistance value and roadway surrounding rock deformation is obvious; within a distance of working face from 70 m to 150 m, the stress of anchor cable decreases rapidly and the deformation of roadway surrounding rock gradually slows down; begond a distance of 150 m from the working face, anchor cable force hardly changed, and the roadway surrounding rock deformation tends to be stable.Therefore, it is determined that the conservative safe position of the support body is 150 m behind the working face.The engineering practice shows that the retracement distance of the support equipment is able to adapt to the deformation of roadway surrounding rock, and the roadway formation effect is good.