Risk-based approach to setting of flyrock 'danger zones' for blast sites

摘要

An approach to the setting of 'danger zones' around blast sites is proposed. The approach is based on risk-assessment principles and is useful in setting danger zones where a 'stand-off' distance cannot easily be accommodated and supporting evidence is needed to justify (or otherwise) a reduced distance (or change to blasting specifications) and/or where the consequences of hazard realization are such that increased confidence is required in setting the distance for a danger zone. Flyrock hazard is used to illustrate the approach. The incidence of flyrock is calculated from available data and the probability that a predicted distance will be exceeded is considered. A simplified example of setting a flyrock danger zone is given to demonstrate the usefulness of a risk-based approach compared with a traditional consequence approach.