Plastic zone analysis of surrounding rocks basing on plastic flow rule

摘要

Based on elastic-plastic mechanical model of soft rock tunnel considering dilatancy expansion softening properties of soft rock, no longer constant volume plastic zone as a precondition.Combined with Mohr-Coulomb criterion in the plastic flow rule established on the basis of lateral pressure coefficient λ =1 symmetry axis planar circular tunnel limit equilibrium conditions.Makes soft rock tunnel deformation stress and analytical solutions closer to the actual, through example calculation compared to other elastic-plastic mechanics further validate the analytical solution for soft rock tunnel instructive.