A softening block approach to simulate excavation in jointed rocks

The instability of rock masses as a result of excavation is one of the most important rock mechanics problems. This paper proposes a new "softening block" approach for the simulation of stage-wise sequential excavations in jointed rock masses. The concept of a softening block is presented and the corresponding algorithm developed and implemented into the original Discontinuous Deformation Analysis program proposed by Shi. The proposed softening block approach obviates the need to remove the excavated blocks from the calculation model, which further simplifies the work of pre-processing for sequential excavation simulations. Finally, two numerical examples are presented to demonstrate the validity and capability of the proposed approach. The results indicate that it can be used to simulate the excavation in jointed rock mass efficiently and accurately.