Abstract

The principal safety risk during blasting operations is presented by the projection of stone chips or other objects. Blast guards are used to reduce this risk, and function by absorbing or stopping the projected objects. This study examined the behaviour of heavy and light blast guards used on construction sites, and characterized the key elements affecting their effective use.

After an initial literature review of dynamiting techniques and projection ballistics, initial-, trench-, and bench blasting operations were observed at a number of construction sites. Although no operation-specific variations were observed, differences in the behaviour of heavy and light blasting guards were identified. While heavy blast guards are composed of tires, and occasionally undergo excessive and dangerous displacements, light blast guards, composed of geotextiles, are less subject to such displacements, and do not present a risk unless there is a gap between two guards. However, the conclusions presented should be interpreted with caution, given the limited number of observations, and the uncertainty with which chip projection was measured.