Further development of GDEM for the modelling of multi-scale dynamic response of rock subjected to blasting and impact

The dynamical responses of rock subjected to blasting and impact have been concerned in most underground projects. Due to the size effects and strain rate enhancement induced by inertial effects, the dynamic responses of rock and underground structures show multi-scale characteristics. Thus, in order to achieve better understanding of multi-scale dynamic responses of rocks, both computation accuracy and numerical efficiency have been taken into account. This is achieved by further development of a continuum–discontinuous element method code, called GDEM, with a new type of dynamic bounding surface damage model being implemented, thus forming a bounding surface dynamic plasticity damage-GDEM model (DB-GDEM). Both continuous and discontinuous mechanical behaviours of rocks have been captured well by the newly developed DB-GDEM model. The main multi-scale dynamic characteristics of rock subjected to blasting and impact, including particle movement, fragmentation of rock mass, stress wave propagation, and failure models, have been captured. Good agreement among modelling results and solutions reported in literature demonstrates the capability of DB-GDEM. The introduction of bounding surface plasticity damage model in GDEM would reproduce a more realistic dynamic damage response of rock compared with the original GDEM model that embedded with conventional constitutive models.