Study on Overlying Strata Movement in Mining Adjacent Working Face of Extra Thick Seam

In order to master the movement law of overlying strata after coal mining in adjacent working faces, FLAC finite element software was used to simulate the sequential mining of adjacent working faces in a mine, and the stress, displacement and plastic failure characteristics of overlying strata after mining were analyzed. The results showed that the residual supporting pressure in adjacent mined-out areas was superimposed on coal pillars in the middle section, resulting in large vertical displacement and shear failure of overlying strata under the action of maximum stress, resulting in simultaneous downward movement of high overlying strata in both mined-out areas. The goaf overburden presents an “increasing-stabilizing” arch failure with the stoping of the working face, forming a double arch failure along the inclination, and a large shear coupling with the middle pillar overburden forms a destruction arch spanning the two goafs. Finally, the characteristics of overburden migration and failure are confirmed by drilling and peeping in the field, and it is more reasonable to take the estimated upper limit value for the failure height of the “two zones” of overburden mining in the adjacent working face according to the empirical formula.