The impact of blasting on excavation design -- A geomechanics approach
- Noranda Technology Centre, Pointe-Claire, Quebec (Canada)
- Blastronics Australia Pty, Ltd., Brisbane, Queensland (Australia)
- BLM Blastronics Canada Ltd., Sudbury, Ontario (Canada)
It is widely accepted that both underground and surface blasting operations can de-stabilize excavations to the point where it can threaten the feasibility of mining through personnel safety or ore dilution. Research has been undertaken to outline a practical method in which the impact of blasting will be accounted for during the early excavation design stage by modelling, and during the following production stages by monitoring rock response to blasting operations. Of the many factors influencing the stability of excavations in rock, a critical one is the natural geological structure. The research work presented in this paper is part of a major effort aimed at integrating blast design with this aspect of rock mechanics excavation design. The chosen approach considers vibrations to be the primary cause for blast-induced rock damage in underground operations, where it is argued that gas effects have a lesser impact due to the usually high stresses confining fractures. Tests were conducted during the Fall of 1992 in an underground experimental drift surrounded by two tunnels designed for observation and instrumentation purposes. A total of five rounds were blasted in the experimental drift: each time the blast design was altered to increase the amount of damage in the test tunnel, which was then observed and quantified from the observation drifts. Analysis of the results focused on establishing a relationship between vibration levels and the extent or degree of fracturing induced. Other practical indirect measurement methods for assessing the extent of fractures in the rock mass, such as high frequency seismic methods, high resolution displacement analysis using a time domain reflectometry (TDR) method, and radar mapping, were also studied by the multi-disciplinary research team.
- OSTI ID:
- 398325
- Report Number(s):
- CONF-9401127--
- Country of Publication:
- United States
- Language:
- English
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