Energy release and damage characteristics induced by fracture planes in face destress blasting.

• New face destress blasting design concept and theoretical analysis. • Energy release and damage characteristics induced by fracture planes under high in-situ stress. • Experiments on rock mass damage induced by single and double fracture surface. During the excavation of the deep tunnel development face, the rock burst will abruptly occur with the instantaneous release of strain energy stored in the rock mass. Face destress blasting as the preconditioning method to fracture the rock mass, release the accumulated strain energy ahead of development face in advance, is considered one of the tactical approaches to reduce the rock burst proneness. However, the challenge of conventional destress blasting is how to effectively fracture rock under high in-situ stress and reduce strain energy accumulation. Therefore, in order to effectively release energy, a new destress blasting design utilizing fracture planes is proposed. First, blasting holes parallel to the maximum principal stress are employed to generate fracture planes. Next, fracture surfaces are used to reflect stress waves to enhance rock damage, so that the rock mass can be fractured by making full use of the explosive energy, and the accumulated energy can be released effectively. In this study, the failure mechanism of the rock mass is first theoretically investigated, and then the reliability of the rock fracture and energy release was validated by combining numerical simulation with experiments. The results demonstrated that this approach can more effectively achieve energy release and fragmentation during destress blasting. [ABSTRACT FROM AUTHOR]