关键词: 深部开采, 复杂采空区, FLAC3D, 数值模拟, 稳定性

Abstract: After decades of mining in a tungsten mine，the mining work in the middle section above -110 m has been nearly completed，but a large number of complex goafs have been left，which has brought hidden dangers to the mining of ore bodies and the safety of underground workers. In view of the stability of the upper multi-layer goaf，the field investigation and rock mechanical property test of the goaf are carried out. Combined with 3DMine and Midas GTS NX software，the stress，displacement and plastic zone distribu‐ tion of the surrounding rock are analyzed by FLAC3D finite difference method. The results show that the dis‐ placement value of F11 vein in 207# ~208# exploration line F11 in the middle section of +40 m and +190 m changes relatively large，and the stress concentration phenomenon is obvious，which is a dangerous area of collapse. In the middle section of + 190，+ 140，+ 90，+ 40，-10 m，204# ~ 207# line No.1 ore vein pillar pillar plastic zone distribution range is larger，almost through the whole pillar，is a dangerous area. Accord‐ ing to the research results，it is proposed to increase the displacement monitoring in the east-west vein group located in the 207# ~208# exploration line in the middle section of + 40，+ 190 m，and increase the stress monitoring in the middle section of + 190，+ 140，+ 90，+ 40 m in the middle section of 204# ~207# ex‐ ploration line No.1 ore vein pillar，and select the key area to implement the treatment measures，so as to pro‐ vide strong support for the safety management of the mine and the future mining work，and promote the sus‐ tainable development of the mine.

Key words: deep mining, complex goaf, FLAC^3D , numerical simulation, stability