Stress distribution characteristics in rock surrounding heading face and its relationship with supporting

FLAC3D was utilized to investigate distribution characteristics of stresses, displacements and plastic areas in the periphery of heading face. The influence of the angle between the roadway orientation and the in situ maximum principal horizontal stress on the stresses, deformation and failure in the surrounding rock were also investigated. Furthermore, the stress distribution characteristics of rock bolting in the periphery of heading face as well as their effects on the unsupported roadway roof were studied. The mechanical interaction between surrounding rock and supporting structure was presented. Generally, the surrounding rock of coal mine roadway should be regarded as discontinuous material. Therefore, the ground response curve of continuous material is not reasonable to study the relationship between surrounding rock and supporting structure. Neither is the ground response curve of supports since there are distinct differences between the supporting mechanisms of supports and rock bolts. Based on field data of the axial forces in rock bolts, which were classified as five types, the ground response curves of rock bolting were obtained and time-space design principles were put forward. Finally, three field sites including a roadway over 1000 m depth, a roadway suffering very intense dynamic pressure and a gob-side entry retained for next sublevel within large depth were presented and compared with the theoretical and numerical results.