Post-peak stress-stain relations of rock mass considering elasto-plastic coupling based on strain-softening model

摘要

Based on Hoek-Brown failure criterion, selecting the plastic shear strain as strain-softening parameter and considering elasto-plastic coupling, the approach of solving nonlinear relations between stress and axial strain, hoop strain and volumetric strain in the post-peak region was proposed by modeling. On this basis, combining with numerical examples, the influence of elasto-plastic coupling on post-peak stress-strain curves and deformation is analyzed. The results reveal that both elastic modulus and poison's ratio coupling have some influence on post-peak stress-strain curves and deformation. In terms of influence extent, the coupling of elastic modulus has larger influence on axial strain than that of poisson's ratio, and the coupling of poisson's ratio has larger influence on hoop strain than that of elastic modulus.