A coupling method for simulating tunnel excavation with block, particle and bar elements

Excavation of tunnel in rock mass refers to complex continuum-discontinuous processes. For capturing the damages side walls and supports bolts/cables, different types elements shall be used same framework. In this work, a novel method is proposed which couples block, particle, bar for simulating intact mass, broken supporting system respectively during excavation. Brittle Mohr-Coulomb fracture constitutive law tensile are introduced describing contact behavior between parts. Penalty springs adopted accounting pre-stresses effects. Moreover, assuring proper transitions forces displacements elements, an interpolation coupling approach presented. Cases considering sections strategies numerically studied, indicating reliability method.