Numerical Simulation Analysis of the Mechanism of Smooth Blasting

Smooth blasting techniques are used to minimize overbreak (or fracturing of rock) beyond the designed boundary of main excavation areas. In recent years the approaches have become more sophisticated, but they remain essentially trial-and-error proposition as far as practical field application is concerned. One of the reasons of this proposition may be the lack of knowledge about the smooth blasting mechanism. In order to make clear the mechanism of smooth rock wall formation in blasting, the authors studied experimentally the blasting crack development in cement mortar specimen. In this study the time lag dependence of the detonations in two adjacent blast holes on crack formation between holes. In the numerical simulation analysis, dynamic finite element method was employed.