Seed wave modelling applications for fragmentation, damage and environmental impact control

Abstract

Modern mine productivity places a very strong focus on achieving high levels of control over fragmentation, wall control (damage to excavation limits) and environmental impact. The introduction and extensive use of electronic initiation heightens the focus of each one of these blasting outcomes, though systems to permit optimisation are not readily or widely available, and are seldom used in any routine manner in the mining industry. Seed wave modelling, in conjunction with electronic initiation, enables blasting engineers to identify optimum timing configurations for any type of blast, with respect to each of the three mentioned blasting outcomes. Fragmentation, either in the body of the blast or in the stemming zone of blasts, can be increased substantially by optimising timing from the point of view of maximising induced stresses within the rock mass, enabling quantification of a fragmentation index for specific vertical bench sections. Damage, either in the bench batter behind a limits blast, or in the underlying berm, can similarly be minimised by careful delay timing, often more effectively than by costly reduction of blasthole diameter, enabling definition of a Probability of Damage curve. Environmental vibration impacts, either in the medium-field as an impact on vibration-sensitive slopes or mine sectors, or in the far-field as an impact on nearby occupied structures, can also be minimised by careful selection of delay timing. This paper presents the use of seed wave modelling as an everyday tool to enable blasting engineers to make engineering-based decisions regarding the delay timing which will bring maximum control over these blasting impacts.

Correlating blast vibrations and geomechanical properties to determine damage profiles and improve wall conditions in open pit mining

“…Furthermore, another very important factor for wall strength preservation is to understand how vibrations and consequently damage are attenuated with distance. Several authors, such as Devine et al (1966), Blair (1999, Hizen (1998), Silva-Castro (2012), McKenzie (2012), andMcKenzie (2013) have studied the behavior of the shock wave generated by the one hole charged with explosive, the seed wave, determining its characteristics (length, velocity, amplitude, frequency) and understanding the relationship between the generation and attenuation of induced vibrations.…”

An innovative technique of simplified signature hole analysis for prediction of blast-induced ground vibration of multi-hole/production blast: an empirical analysis

“…It was in the 1980s when wave interference concept began to be introduced (Anderson et al 1985;Crenwelge and Peterson 1986) to control blast vibrations. Previous researchers (Chiappetta et al 1986;Hinzen et al 1987;Yuill et al 2002;Spathis 2006;Lusk et al 2006;Christopherson et al 2008;Anderson and Brinckerhoff 2008;Yang et al 2009;Silva et al 2016;Scovira 2011;McKenzie 2013;Agrawal and Mishra 2018b;Agrawal and Mishra 2017) had shown the benefits of the use of wave interference to reduce the ground vibration levels in a blast event. An example of signature hole simulation report using Advance Blastware TM Module is shown in Fig.…”