Abstract:
Analysing the stability of deep mine passages and rockburst propensity is of great significance to the safe construction of mines. The stability of the circular drainage tunnel under the influence of geostress on the Tibetan Plateau was investigated by numerical simulation using a large cross-section deep buried long roadway in Julong Copper Mine as the research object. The propensity for rockbursts after roadway excavation was analysed. The results show that the internal stresses in the surrounding rock of the circular drainage tunnel are dominated by horizontal stresses, and the maximum principal stress is 32 MPa. In the 16 sections of the drainage roadway, the stresses are mainly concentrated in sections DE, EF and DG of the roadway. The horizontal displacement of the roadway enclosure is greater than the vertical displacement. The maximum displacement of the circular drainage roadway spreads in all directions with point M as the centre. GM section, HL section, KN section of the roadway perimeter rock have occurred a large deformation, for this area of the roadway should be strengthened support. The maximum elastic strain of the DE, EF and DG sections of the roadway reached 1.01×10
5 J/m
3, showing a tendency of rock explosion. Weakening of local stress concentrations in the rock mass by reducing the excavation scales. On-site monitoring has shown the modelling results to be reliable. The results of this paper provide theoretical references for the construction of ring drainage tunnel and ground pressure disaster prevention and control in Julong copper mine.