Abstract: In this paper, to investigate the roof deformation characteristics with full-mechanized caving face in extremely inclined and thick coal seam, taking the extremely coal seam with the dip angle of 45o in the north panel of Wudong coal mine, Urumchi coal field as research object, the roof mechanical model of extremely inclined caving face has been established by beam theory, and the deflection equation in specific settings has also been summarized. Meanwhile, FLAC3D numerical simulation was further applied for roof deformation mechanism. Analytical results indicate that the inclined length of roof beam has enormous impact on roof deformation. The roof deformation gradually increases with the increasing of roof dangling area, especially in its above middle area. Deformation region expands from the central part of roof to the outward part, and its value obtains the minimum neighboring the supporting point of the beam structure. Plastic zones characteristics of roof structure in the inclined direction was monitored by geological penetrating radar, and the roof deformation characteristics were assumed. Generally, the in-situ monitoring results are basically identical with the theoretical and simulated analysis.

Key words: extremely inclined coal seam, beam structure, mechanical model, ground penetrating radar, numerical simulation