24 / 2020-03-02 17:13:49

Destress blasting modelling - a state-of-the-art review

destress blasting; numerical modelling; underground mining; rock mass fracturing; stress release

Destress blasting, as a proactive rockburst prevention method in mining, has been applied to numerous mining conditions with the aim of preconditioning highly stressed rock mass to mitigate the risk of rockburst occurrence in deep mines. However, the application of destress blasting mostly depends on engineering experience, while its mechanism and efficiency have not been well understood. Rapid advances in computer technology make numerical simulation an economic and effective method to study the rock blasting effect. Enormous research efforts have been made to numerically investigate the blasting fracture mechanism, optimize blasting design, and assess the efficiency of destress blasting. This review focuses on the state-of-the-art progress in numerical modelling associated with destress blasting over the last two decades. Some commonly used modelling methods for destress blasting are compared and reviewed. Currently, two different ways of modelling based on static and dynamic modes respectively are typically used to study the effect of the blasting. In terms of static method, destress blasting is simulated by modifying the deformation and strength properties of the rock mass and the post-blast stress state in the destressed zone is obtained using those weakened parameters. On the other hand, based on the developed dynamic modelling technique, the dynamic fracture process of coals and rock masses can be presented, during which the predetermination of the scope of damage induced by blasting is not necessary. Moreover, the extent of damage zones around the blast hole can be precisely estimated in the dynamic modelling method by considering time-varying blast pressure and strain rate dependency on the strength of rock mass. The paper also presents the difficulties and limitations associated with the modelling works of destress blasting in the rock mass.