DBPapers
DOI: 10.5593/SGEM2015/B13/S3.028

DETERMINATION OF THE DYNAMIC PHENOMENA IN BOREHOLES AFTER BLASTING

M. Mikolas, P.Hrbac, M. Mikolas, A. Policka, B. Nec
Friday 7 August 2015 by Libadmin2015

References: 15th International Multidisciplinary Scientific GeoConference SGEM 2015, www.sgem.org, SGEM2015 Conference Proceedings, ISBN 978-619-7105-33-9 / ISSN 1314-2704, June 18-24, 2015, Book1 Vol. 3, 211-218 pp

ABSTRACT
This article addresses the use of piezoelectric sensor for measurements of the dynamic phenomena that arise during the large scale blasts. Outcomes of measurements and evaluation of the resulting pressure can help us to improve proposals and implementation of blasting explosives and increase functionality of fuses.
In our paper we will evaluate the measurement principle and describe influences resulting in pressure on detonators and explosives. One of the chapters will also assess and interpret specific cases of pressure measurements done in the field. Enormous compressive forces occur in Boreholes during the conversion of explosives and these can have varying effects on the used explosives and the rock itself. These dynamic pressures develop the greatest strength near initiated charges due to detonation neighboring Boreholes. Another possible source of pressure forces arises from the other partial charges in the same borehole which forerun the affected blast.
Measurements of these pressures generated during the blasting works can additionally help us evaluate more effectively and use more practically the pressure forces during the blasting. We will be also able to influence these forces and decrease the failure rates by having broader knowledge. During blasting arise in practice various phenomena in the form of pressure or shock waves. The speed which the waves are spreading is determined by the density and elasticity of the rocks. Blasting is caused by stress wave that arises incrementally with detonation pressure on the walls of the borehole. This stress wave is spreading itself in spherical or tapered surfaces. The pressure wave is then reaching the environment and it is changing itself into tension wave. Interface for this can be any open space.

Keywords: Dynamic phenomenon, Piezoelectric sensor, Explosives, Electronic detonator E * Star