Abstract: The stopes stability in different stages of stoping and filling under complicated stress condition was studied in the downward sublevel cut-and-fill mining stopes of Jinchuan No.3 mining area.According to the relationship of maximum horizontal principal stress σ_H，minimum horizontal principal stress σ_h and the vertical principal stress σ_v，the in-situ stress field can be divided into σ_h stress field（σ_H >σ_h >σ_v）,σ_hv stress field （σ_H >σ_v>σ_h）and σ_v stress field（σ_v >σ_H >σ_h）.The stability of stoping and filling phase-1 of two-sided orebody，phase-2 of one-sided orebody and one-sided filling body，and phase-3 drifts of two-sided filling body was analyzed under those three kinds of stress field by using the numerical simulation software FLAC^3D.The results showed that if the stress field changed from σ_h stress field to σ_hv stress field，until σv stress field，the tensile stress and maximum displacement at phase-1 are gradually transferred from the sides to the roof and bottom，while the tensile stress and the maximal displacement of the phase-2 and phase-3 drifts were generated at the roof of drifts，and expanded with the stress field changed.It is showed that the earlier stoping affected the in-situ stress distribution and leaded that rock stress distribution and deformation law of late stoping and filling under three kinds of stress field gradually tend to be the same.The larger horizontal stress of σ_h stress field has a more poor stability of stopes under σ_h stress field comparing with two other types of stress field.But this trend has weakened in late stoping and filling.

Key words: Complicated stress, Different stages, Cut-and-fill stoping, Stope stability