Prediction of plastic zone size around circular tunnels in non-hydrostatic stress field

摘要: Abstract This paper discusses the calculation of plastic zone properties around circular tunnels to rock-masses that satisfy Hoek–Brown failure criterion in non-hydrostatic condition, and reviews displacement, basis convergence–confinement method hydrostatic condition. A two-dimensional numerical simulation model was developed gain understanding shape. Plastic radius any angles tunnel is analyzed measured, using different values overburden (four states) stress ratio (nine states). equations were obtained from fitting curve data which are dependent on ratio, angle Finally validation this equation indicate results predict real appropriately.