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By Lifeng Li, Jhon Silva-Castro

"Signature Hole Technique is one method to assess the vibration waveform of a production blast.Methematically, it is the convolution between a prior measured waveform of a single blast hole (signature) and a given time delay sequence (comb function). Being an advantage, the inverse operation of convolution, known as deconvolution, can be used to estimate the signature."

Jan 1, 2017

By Norman Paley

A blasting project was undertaken at the Teck Alaska Red Dog Mine to determine the extent that Semi-Autogenous Grinding (SAG) mill throughput could be increased by using electronic detonators. The Julius Kruttschnitt Mineral Research Centre (JKMRC) blast fragmentation, jaw crusher, and SAG mill breakage models were used to relate changes in the blast fragmentation measured with the SPLIT image analysis system to the SAG mill performance. For optimum performance a SAG mill requires a particular size distribution; a number of large rocks to facilitate breakage by impact, as few as possible middle size rocks that become critical size, and the maximum fines which will pass quickly through an open-circuit mill. Physical constraints of drill and charging equipment size limit the extent that pattern geometry can be changed, and the powder factor increased, to maximize fines. However, a growing number of studies have shown that the use of electronic detonators can lead to increased fragmentation and greater muckpile uniformity, providing an alternate means of increasing primary breakage by blasting. Unfortunately results in the literature rarely quantified the changes to the fragmentation distribution. The measured gyratory crusher fragmentation of 2,750,000t of ore was used to compare stockpiles constructed from shots using pyrotechnic detonators to those using Orica i-kon electronic detonators. In the first stage of the study, stockpiles shot using 25 ms inter-hole timing with pyrotechnic detonators were compared to stockpiles shot using the same inter-hole timing with electronic detonators. In the second stage of the study, stockpiles shot using 17 ms inter-hole timing with pyrotechnic detonators were compared to stockpiles shot using 8 ms inter-hole timing with electronic detonators. When electronic detonators were used with the inter-hole timing kept constant, fragmentation uniformity was slightly increased, but mean fragment size increased by 20%. When electronic detonators were used with faster inter-hole timing, fragmentation uniformity was slightly reduced, but mean fragment size decreased by 30%. Modeling was used to determine the SAG mill throughput which could be expected from this change in fragmentation to determine the pairs of pyrotechnic and electronic blast pattern geometries that would provide similar throughput. The economic benefit from the electronic detonator shots was calculated to assist in determining the optimum blast designs for their use.

Jan 1, 2010

By John W. Brown

"Adequate dust control in and around rock drills is a problem that must be solvedfor the health and safety of workers running the drill as well as those working around thedrilling operation This paper will discuss the designs available from most drill manufacturers todayand the effort ‘nvolved in keeping them effective on a productive basis."

Jan 1, 1999

By Robert Hopler

Although electrical instruments were being widely introduced into the study of seismic tremors, attempts to understand and quantify shocks from blasting continued to use rather primitive methods well into the 19th century.

Jan 1, 2007

By Kaushik Dey

Bord and pillar is the most predominant method of wining of coal in Indian underground coal mines. Development heading in coal mines often encounters roof stability problem and results in roof overbreak. Research on this reveals that the blast-induced ground vibration may have significant contribution in roof overbreak, especially, when solid blasting is carried out in the bord and pillar method. Solid blasting, in general, is associated with higher charge confinement due to lack of free face and generates higher ground vibration, which in turn results in excess overbreak.

Jan 1, 2008

By C. Lownds, U. Steiner

In 2008 a paper from the same source describing four actual cases of exposure of electronic detonators to lightning strikes was presented. It was shown that electronic detonators, like other initiation systems, are vulnerable to very close or direct lightning strikes. At the time of submitting this abstract no further incidents with lightning have been experienced. As a result of those original incidents, and in order to understand how the safety devices inside electronic detonators break down, two series of tests have been done, each with 2 detonator designs. In the first series detonators were subjected to capacitor discharges up to 6kV and 1kJ in energy. In the second series the intensity was increased to 800kV and 24kJ in energy. In the second series, more electrical energy was delivered to the detonator assembly than the explosive energy of the detonator. In both series both detonators showed a spectacular ability to resist very high discharge energies. The tests are described in detail with supporting photographs. The data for both pin-to-pin and pin-to-case (more relevant to lightning) are presented and discussed. The mechanism of breakdown of safety devices is now understood better and the learning is being used to design more robust products. This high-voltage testing is relevant in understanding how electronic detonators might initiate as a result of a very close or direct lightning strike 1. Orica

Jan 1, 2009

Explosive manufacture, handling and transportation is hazardous and special precautions should be taken while manufacture, handling and transportation. Various regulations and rules defined in explosive act and factories act of India are discussed in this communication. General process control measures during the manufacturing of different types of explosives are also dealt in detail. Various processes hazardous in manufacture of various explosives like slurry explosives, PETN, detonators, styphnic acid, lead azide and lead styphnate and special precautions to be taken during the manufacture of the above explosives are also discussed.

Jan 1, 2007

By Randy Martin, Jessie Bonner, Peter Boyd, Mark Leidig, Timothy Rath

We conducted the Vermont Damage Experiment in central Vermont during July 2008. Five single-hole explosions with yields ranging from 60.8 kg (134 lbs) to 122.5 kg (270 lbs) were detonated in homogeneous, low fracture density granite. The goal of the experiment was to quantify the different levels of rock damage around the source and then relate the seismic wave generation to the degree and distribution of damage and fragmentation. In addition, explosives with different velocities of detonation (VOD), including black powder (0.53 km/sec; 1737 ft/sec), heavy ANFO (4.8 km/sec; 15734 ft/sec), and COMP B (8.1 km/sec; 26574 ft/sec) were detonated to relate the VOD to seismic wave generation and extent of damage zones in the source region. Over 120 seismic stations were deployed to record the explosions at distances between 5 m and 30 km (15 ft to 19 miles).

Jan 1, 2010

By Behrouz Ohadi, Kamran Esmaeili, Bibhu Mohanty

In most metalliferrous open pit mines with heterogeneous orebodies, blast-induced rock movement is a crucial outcome that has unfavorable impact on ore and waste segregation in the post-blast muck pile, resulting in either ore loss (the ore is misclassified as waste and sent to the waste rock dump) and/or ore dilution (waste is misclassified as ore and sent to the processing plant). While many studies have been carried out to assess the influence of blast design parameters on blast-induced rock movement, the influence of rock mass characteristics in these studies have been overlooked.

Jan 1, 2018

By Sandra Penttinen

To assist blasting professionals with the creation, documentation, and appropriate methodology to standardize the data collection of the pre and post blast investigation process. Penttinen Associates will present a logical non-technical presentation focusing on: Why pre-blast surveys SAVE How to prepare for pre-blast inspections What to do in preparation of pre-blast inspections The creation of an industry standard all-inclusive pre-blast document Establishing pre-blast inspection operational standards Preserving the data.

Jan 1, 2001

By Peter Dare-Bryan, Will Hunt, Lee Julian

It is well-known that blasting has an economic effect on grade control activities. However, until recently, methods did not exist for measuring the grade control value change caused by the blast. Rules of thumb were the best method to minimize ore loss and dilution, as simulation has been traditionally constrained by time and computer power. Even with these rules followed, an extensive study performed on over 150 blasts showed that the value change caused by the blasts followed a normal distribution – some blasts created value, and some blasts destroyed value. The question naturally asked was “How can we ensure the blast designs are optimized to create value?” Recent advancements in computer power have enabled real-time blasting simulations that create post-blast grade control models before the blast is fired. Understanding what will happen before it happens allows blasters and grade control personnel to iterate designs, searching for the highest value achievable.

Feb 6, 2023

By Sven-Erik Johansson, Gosta Rundqvist, Donald Jonson

In Stockholm a new road traffic system called Södra Länken (Southern Link) will be in operation in late 2004. The total length of the road system is 6 kilometres of which 4,5 kilometres run through tunnels under suburbs immediately south of Stockholm inner City. The new traffic tunnels together with existing Metro tunnels, which mostly are in rock, will be the determining factor for blast design for many projects in the future. To set reasonable and safe permitted vibration levels the Swedish National Road Administration, Stockholm Region and Stockholm Transport Rail System have together financed a project to determine guide levels for blast-induced vibrations in traffic tunnels in rock. The purpose of the project has been to establish guide levels that are appropriate for different types of rock tunnels.

Jan 1, 2004

By Dr. Kyle Perry, Ryan Sibley

Rock blasting is an inherently difficult field to quantify independent & dependent variables and the specifics of how the energy interacts with the material for a number of reasons. Independent variables such as geology are innumerable and stochastic, thus, on a laboratory and full-scale basis these variables are assumed to be homogenous across the desired rock boundary. Dependent variables are difficult to quantify in the laboratory based on the specific aspect of the fracture mechanisms that caused the fracturing. The same variables are difficult to quantify in the field because of the shear amount of material being blasted. The energy interactions with the material are difficult to quantify due to the rate of the reaction and the lack of quantification of independent variables. The second main issue with laboratory scaled rock blasting is the nature of the small form-factor explosives required for use in a scaled setting. These explosives that are utilized, traditionally PETN detonating cord, have a greater ratio of potential energy converted to shock energy rather than gas energy when compared to traditional field explosives, such as emulsion or ANFO. Research over the past decades has indicated that gas pressure has the greatest contribution to rock blasting performance, such as fragmentation and material throw. The factor of varying ratios of energy production has not been discussed in any of the reviewed publications. Publications discuss dimensionless scaling, dynamic similitude, and length-based scaling, however, none of these scaling methods discuss the ratio of energy production. The main focus will be correlation of energy production ratio of shock versus gas to dependent variables. This paper analyzes previous publications within rock blasting and related field as they pertain to scaling procedures and will highlight the similarities and differences in the various publications and detail the observed omitted variables that possibly lead to skewed data.

Jan 21, 2025

By Pavel A. Torres, Darwin Torres, Sandro Huaman

Given the limited efficiency of blast-induced ground vibrations prediction empirical models, due to the complex geological system from a Peruvian mine. An artificial neural network was built in order to get better results. More accurate and precise predictions allowed the generation of blasting domains for future designs and decision making.

Feb 1, 2020

By Darío Innamorati, Jorge Oliva

Cerro Vanguardia is a known gold and silver deposit located in the province of Santa Cruz, Argentina. The mine has been in operation since 1998 and is thought to be one of the most important mines in Patagonia. More than 102 epithermal quartz veins have been identified in the area, with variable lengths, thicknesses, orientations and dips that constitute what is possibly one of the most extensive outcropping vein systems on earth. Veins are vertical and have variable depth. For this reason, the deposit is currently mined with a variety of extraction methods. This operation is made up of more than 60 open pits and 20 underground access ramps to exploit the deepest high grade narrow veins. This study is focused on the combination of underground exploitation with open pit blasting. That is, those production stopes in the upper levels of underground mines and their interaction with the damage levels in the final slope of open pit mines, as well as in the study of the impact of the generation of vibrations from the blasting of open pit mines and their influence on underground mines. Considering the current stage of the mine, after 20 years of operation, Cerro Vanguardia faces the need to mine deeper deposits in the face of increasing costs and declining grades. For this reason, it is essential to study the interaction of these exploitations. From a personnel safety point of view, this interaction must be well coordinated so as not to affect people and equipment. Likewise, the generation of vibrations due to blasting must be studied, which would produce new cracks, potentially generating overbreak and dilution. The main objective of this study is to determine the possible causes and influences of the blasting interaction in open pit and underground mines, seeking an optimization of the blasting process and a safety standard for personnel and equipment. To achieve these goals, this study includes a vibration monitoring plan to analyze the charge performance and determine rock constants. With the use of specialized software, damage modelling and simulations are used to determine values of damage in order to reduce overbreak. In addition, this plan contemplates the estimation of flyrock in blasting where underground work is connected to the surface, determining safety distances when carrying out a blast.

Jan 21, 2025

By R Holmberg, C Sjoberg, B Larsson

This paper describes the excavation of an underground naphta storage facility at Stenungsund in Sweden. The main purpose with this paper is to give an overall view of how the excavation was carried out and in what type of bedrock the storage was built. Emphasis has been done to highlight the importance of using cautious blasting to avoid blast damage in the remaining rock. Attempts has also been done in order to evaluate what the degree of Swedish cautious blasting has meant for the rock support costs during the construction period.

Jan 1, 1984

By César Ugaz, Jorge Cardenas

Mitigating the vibrations resulting from a blasting rocks is one of the most common challenges that Peruvian mining has, since if this impact is not mitigated it can generate discomfort and altercations with neighboring communities and also puts the continuity of the mining project at risk. In that sense, we must establish control parameters to mitigate these effects as much as possible. As a starting point we must establish areas of interest that in this context would be the communities near the mine; first stage to carry out constant monitoring at these points, the registration of vibrations and noise is vital for the success of this control, with this information we can establish predictive models, the registration of elemental waves and the evaluation of human perception. In a second stage, this information allows us to make decisions in engineering such as the selection of delay times, elaboration of detonation sequence schemes, maximum amount of operating load per delay window, as well as the use of special load designs (Decks). There is a fear that these controls generate negative impacts to the process, referring to fragmentation, dig rate, throughput, etc. Since we limit the explosive load necessary for the results we need. To avoid this we use "Decks" type load designs under a sequencing between these under time calculations by elemental waves, which generate a reduction in vibrations up to 50%, also complying with strict regulations without affecting the power factors to comply with our performance indicators. Finally, in a third stage we must carry out a constant evaluation of results according to the progress of the mine.

Jan 26, 2026

By John Tatom, Michelle Crull, Robert Conway

The US Department of Defense Explosives Safety Board is sponsoring the development of a risk-based explosives safety siting program, SAFER. The fragment and debris hazard generated at the potential explosion site (PES) is critical at an exposed site (ES) over a significant range of standoff distances. The Science Panel Impact Debris Evaluation and Review (SPIDER) test program has been planned to develop improved predictions for the hazards inside an ES by fragments and debris. Data will include the mass and velocity required for perforation of the test cross-section and the characteristics of all debris produced inside the ES.

Jan 1, 2010

By Joshua Hofman, Braden Lusk, Erin Morris

Explosions in urban environments, whether of accidental or malicious cause, often result in extensive injuries, loss of life, and property damage. The ability to predict the damage inflicted by these events is highly sought after; in order to predict damage, the behavior of blast waves within these environments must be quantified and understood. Urban constructs such as buildings and roadway intersections affect the natural propagation of a blast wave, intensifying or rarefying the wave depending on their arrangement.

Jan 1, 2012

By Jay Smerekanicz, Florin: Pedersen Gheorghiu, Alan Cameron

In order to expand the capacity of Modern Landtill, a groundwater extraction system consisting of a linear system of pumping wells over 2,700 feet long had to be replaced. The new system would be covered by landtill cells to a depth of approximately 400 feet, and therefore would have to be maintenance free. In addition, the new system had to be proven to be more effective than the previous system, groundwater extraction had to be maintained during construction and construction could not disturb either the landfill operation or nearby residential neighbors.

Jan 1, 2001