Study On Behavior Of Superincumbent Strata In Mining 45 Degree Coal Seams Using Horizontal Section Top-coal Caving

Detailed researches are implemented to behavior of superincumbent strata in mining 45 degree coal seams using horizontal section top-coal caving in this paper. The structure is founded in superincumbent strata after mining, namely Incline rock-beam and Instability of structures will affect strata behavior and result in destruction of superincumbent strata.On the superincumbent strata of the study, simulating model test is firstly carried to manifest there must have certain structure in superincumbent strata. Secondly, come out the formula of superincumbent strata load and roof's utmost span. By contrasting with pressure test observation data, the conclusion that there is a structure in superincumbent strata is demonstrated. "Incline rock-beam"the structure is always goes against after the working surface above main roof snaps forms along inclines the direction three-pinned arch, manifested "Voussoir beam" the structure basic characteristic, its scope was upward expansion "the balance - lost unceasingly steadily - balances again - loses again steadily" the dynamic process. Furthermore, the mechanical mode of the structure is established, and some factors of affecting structure stability are also studied. Finally, using the FLAC3D finite element calculation, the correctness of above conclusions is proved.In a word, the use of the pressure test observation, similar simulations, numerical simulation, theoretical analysis, and other means, analyzed systematic to the behavior of superincumbent strata in mining 45 degree coal seams using horizontal section top-coal caving ,and it is for the 45 degree coal seams safe, high-yielding, and high efficiency production of research is of great significance.