Analysis on Hoek-Brown rock roadway large deformation based on convergence confinement method

The elastic-plastic theoretical analysis of the axisymmetric circular roadway is the basis and important problem in the construction process of deep soft rock roadway. Based on the basic theories such as the convergence confinement method, finite deformation sub elastic-plastic theory, Hoek Brown failure criterion, strain softening constitutive model and so on, the basic research on the squeezing large deformation caused by the excavation of circular roadway in deep soft surrounding rock is carried out. On the basis of research on large deformation, uses the brittle plastic analytical solution of surrounding rock after tunnel excavation to characterize the strain softening zone of rock mass. The analytical solution of stress, deformation and radius of each zone of surrounding rock of deep soft rock roadway in Hoek-Brown rock mass is briefly described. The effectiveness of the model is verified by comparing the field monitoring data and the calculation results of different mechanical models, and the influence of the relevant strength parameters of the rock such as m, s, a are analyzed. Based on the difference of surrounding rock characteristic curve under the theory of large deformation and small deformation, the support suggestions for soft broken rock mass are proposed, which provides theoretical analysis means and guidance for support engineering design of soft surrounding rock under deep and unfavourable conditions.