Numerical analysis of stope stability based on coupling of MIDAS/GTS and FLAC3D

Taking industrial field test at Kelatongke Copper-Nickel Mine in Sinkiang, which uses the back-filling mining method based on environment reconstructed deep-hole introducing caving, as an engineering background, the three-dimensional mesh model of ore body excavation was constructed by using the MIDAS/GTS software, and then the model data were transformed into FLAC^3D to build the numerical simulation model, after which the simulation calculations were carried out. Finally, according to the simulation calculation results, the deformation responses and stress characteristics of artificial roof and surrounding rock were analyzed. It is proved that after the ore in the stope was mined out, the underneath of middle of the artificial roof had tensile zone, the maximum stress value was 0.21 MPa, whose sinking displacement also reached the maximum value, up to 43.2 mm. The left end of artificial roof was subject to shear stress, the phenomenon of stress concentration is obvious. The upper and lower surrounding rock of stope are under a state of tensile stress, maximum tensile stress value is 1.0 MPa, and the displacement of the lower surrounding is greater than that of the upper surrounding rock, up to 47.3 mm. Building a 9 m thickness concrete structure as a safety manual roof can ensure safe production in stope under the roof.