Development of site specific blasting index parameters based on single hole blast test cratering

ABSTRACT

An experimental method is proposed to assess blasting requirements based on in-situ cratering behavior. The method relies on single hole blast (SHB) tests to derive burden-dependent relationships. A non-linear crater model of the form $Y=C{b}^s$ is calibrated from SHB test results to describe the cratering behavior. Parameters $C$ and $s$ represent characteristic blastability index parameters that depend on geomechanical and operational conditions. A series of experimental SHB tests were conducted at three hard rock mines. The craters were mapped to capture the breakout profile and calibrate the model. Results showed that coefficient $C$ presents an inverse linear correlation with burden $B$, while exponent s is approximately constant for a considerable range of burden values. Experimental results are used to define burden dependent relationship for bench blast designs and blasthole placement in underground development rounds. A complementary analysis addresses the prevalence of multiple cratering mechanisms according to geology and burden dimension.

KEYWORDS:

• Rock blasting
• single hole blasts
• rock fragmentation
• rock engineering
• geomechanical properties
• mining engineering
• cratering mechanisms
• blastability

Acknowledgements

This work was funded in part by the Natural Sciences and Engineering Research Council of Canada through its Discovery Grant program (RGPIN-2022-03893). The first author thanks Prof. Michel Aubertin for his constructive comments on the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the Natural Sciences and Engineering Research Council of Canada [grant number RGPIN-2022-03893].