Analysis of Separation and Dislocation Characteristics of Layered Roof in the Mined-Out Areas

Abstract

The computational model based on the shallow mined-out areas was built by using FLAC3D, and the separation and dislocation characteristics of the layered roof in the mined-out areas were analyzed under different conditions. The results showed that the maximum value of the layered roof separation increased with the increase of the mining width, and that value decreased with the increase of lateral pressure and the cohesion between layers. The separation curves of the layered roof showed the shape variation from the symmetry flat arch to the asymmetric steeple arch and then to the linear form, the maximum separation value of the layered roof exhibited a three-stage tendency of a gradual increase, a steep reduction and a slight change, and the maximum dislocation value of the layered roof presented a two-stage tendency of firstly slow growth and then rapid growth with the increase of the dip angle of coal seam.