Services on Demand
Article
Indicators
Related links
Cited by Google
Similars in Google
Share
Journal of the Southern African Institute of Mining and Metallurgy
On-line version ISSN 2411-9717
Print version ISSN 2225-6253
Abstract
LU, W. et al. A modified model to calculate the size of the crushed zone around a blast-hole. J. S. Afr. Inst. Min. Metall. [online]. 2016, vol.116, n.5, pp.412-422. ISSN 2411-9717. http://dx.doi.org/10.17159/2411-9717/2016/v116n5a7.
After detonation of the explosive, the final blast-induced damage area around the blast-hole falls into three categories, namely crushed zone, fractured zone, and elastic deformation zone. This paper presents a modified model to calculate the size of crushed zone around a blast-hole in drill-and-blast, with the hoop compressive stress and cavity expansion effect taken into account. The material in the crushed zone was assumed to be a granular medium without cohesion, but with internal friction. On this basis, the formula for crushing zone radius was derived. The proposed approach was verified with tests reported in the literature and the simulated results from SPH-FEM coupled models. A full statistical analysis was also carried out, and the predicted values were found to be in better agreement with the test results compared with other models. A sensitivity analysis of the modified model showed that the size of the blast-induced damage area is mainly affected by the following factors: rock mass properties, in situ stress, and borehole pressure. In particular, the roles of borehole pressure and in situ stress are discussed. Finally, suggestions are made on how the size of the crushing zones can be decreased.
Keywords : drill and blast; crushed zone; modified model; hoop compressive stress; cavity expansion.
![](/img/en/iconPDFDocument.gif)