Modified RHT model for numerical simulation of dynamic response of rock mass under blasting load

Rock blasting is an extremely complex physical process.It is essential that the numerical models are capable of describing the material behavior subjected to different stress state.Based on the defects of standard RHT model for describing the blasting process, this paper proposes some modifications to the model formulation, which include a bilinear tensile softening model, a Lode-angle dependent residual strength surface, and modified defini-tion of the tensile-to-compressive meridian ratio.The improvement of the performance of the modified RHT model as implemented in SHALE is demonstrated using numerical sample tests.Further, the simulations of blasting crater test are carried out via using the modified RHT model and the standard RHT model respectively.The results show that the radius of the blasting crater simulated by the modified RHT model is more consistent with the field test result, which verifies the rationality and accuracy of the modified RHT model.It demonstrates that the modified RHT model can be of certain value in the numerical simulation of dynamic response of rock mass under blasting load.