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By Jason Rock, Rob Thompson, Lee Julian

This paper presents an innovative shift in inhibited bulk products with specific reference to their manufacture and application.

Feb 1, 2020

By Donald J. Westmaas, Fred C. Drury

The factors affecting the selection and use of exploisves have changed radically in the past three decades. The objective of this paper is to point out considerations which should now be employed by the Explosives Engineer in his selection and use of modern chemical explosives.

Jan 1, 1978

By Remi Proulx, Ruilin Yang

The effectiveness of presplit in soft or fractured ground is hard to visualize or quantify. There have been many attempts by the blasting community to measure and quantify the effectiveness of presplit blasts. Various methods have been adapted by different researchers, and the results are debatable.

Jan 1, 2019

By Timothy Smith, Matthew Ryan, Dr. Anthony Konya

Hybrid specifications are a relatively new style of specifications specifically for the drilling and blasting industry that has seen widespread use over the last decade with the U.S. Army Corp of Engineers. This paper analyzed how this methodology was applied to develop this specification for the Soo Lock Deepening Project.

Feb 1, 2020

By John Brennan

Necessity, they say, is the mother of invention. Certainly that sentiment held true during the early stages of explosive engineering. While seaside forts were concerned over static ignition of their black powder caches in the 14th century1, the mining industry in the 1800s were plagued by accidents surrounding the ignition methods for their black powder blasts.

Jan 1, 2011

By Lon Santis

This paper analyzes 110 serious accidents that occurred during the use of commercial explosives in mining, construction, and other industries since 1992. Data from the Mine Safety and Health Administration (MSHA), the Institute of Makers of Explosives (IME) members’ reports, and media reports were used. Only accidents that resulted in a fatality, significant lost work time, or injury to the public were considered in this analysis. The accident data were analyzed for trends in frequency, type of industry, cause, type of individual harmed, and geographical region. Although the data showed that explosives accidents are decreasing in frequency, still, 29 people were killed and 134 injured. Eightyfive of the accidents occurred in mining, 17 occurred in construction, and 8 occurred in other industries including oil recovery, seismic exploration, agriculture, logging, boiler cleaning, and avalanche blasting. As other studies have shown, flyrock and failure of blast area security caused over half of the accidents. Mishandling, misfires, or fumes caused just over one-third of the accidents. Lightning and drilling into explosives were responsible for the remainder of accidents.

Jan 1, 2003

By Andre Koekemoer, Gys Landman

At the moment, electronic initiation is migrating from a position of a specialist niche to that of a more widely applied technology. Ease of use and deployment rate are becoming aspects of greater concern for end users.

Jan 1, 2011

By Joseph A. Meyers

Explosives techniques and technology are constantly evolving and improving, yet basic communication and business skills are not being used regularly. Many potential blasting projects never occur due to simplistic, basic factors, such as a lack of communication. Articulate communication is the key component in the blast approval process, which has changed remarkably from how business was conducted fifty years ago. Imperative to the approval process is communication outlining the safety and benefits of the blasting project.

Feb 1, 2020

By Natalie Zeleznik, Brian Hawkins, David Bradley, Rachel Gooding, Patrick Wilson

"The United States (U.S.) Department of Homeland Security (DHS) Directorate of Science and Technology (S&T), utilizes a probabilistic risk assessment (PRA) approach to explore the risks (anduncertainty) from chemical, biological, radiological and nuclear (CBRN) threat agents to the Homeland.This end-to-end risk methodology considers a broad range of hazards incorporating emergingtechnologies, available countermeasures and input from the Intelligence and Law Enforcementcommunities (IC/LE) to evaluate the acute risk to human health due to an attack on the U.S. homeland. The PRA generated output provides a mechanism to examine risk mitigation strategies, critical vulnerabilities, critical data and knowledge gaps and relative risk rankings of materials, targets, classes of compounds and scenarios."

Jan 1, 2017

By R C. Sittig

The manufacture of commerical detonating cord by the "wet process" technique is discussed. Raw material variability as a potential source of production problems is examined. Comparison to the "dry process" method is made. Inert samples, illustrating the cord's construction at various points in the production process, were distributed.

Jan 1, 1976

By Douglas Bartley, Kevin Hachmeister, Rich Barry

The use of explosive energy as a tool in mining and construction is the most effective way to move large amounts of rock that is otherwise unable to be efficiently excavated. Since the early days of explosive engineering utilizing black powder initiated by cap and fuse to the present day diversity of specialty products and technologies the goal has always been to "Break and Move" as much rock for the least expense possible. It has primarily been the competitive nature of our economy that has driven the advancement of technological innovations and practice. However, the concept of removing rock is not specific to the mining and construction industry. Since the dawn of creation, man has used rock as a medium to express his creativity in the form of sculpture. Even though the process of sculpture requires the removal of rock, the final work is defined by the rock that remains intact. This typically necessitates the extreme care of the sculptor to painstakingly chip away the rock allowing the image to emerge from the original mass of stone. The famous sculptor Michelangelo once said, "I saw an angel in the marble and carved until I set him free."

Jan 1, 2004

By H. S. Venkatesh, G. Gopinath, R. Balachander, G. C. Naveen

Punatsangchu Hydroelectric Project Authority is constructing 1020 MW underground hydroelectric project in Bhutan. The project envisages construction of concrete dam, Desilting Chamber, Head Race Tunnel, Power House Complex and Tail Race Tunnel. Tunneling is one of the major activity in any underground projects as they are driven for multiple activities. By and large the tunnels are a major part of connecting networks from surface to caverns/underground working sites. Many tunnels in hydropower project are part of water conducting systems and one such important tunnel is the Tail Race Tunnel in this project and had to be excavated in thinly foliated rockmass conditions by D&B method.

Feb 1, 2020

By R. Ranjan

Stanstead granite has been investigated with respect to its dynamic compressive strength and its strain-rate dependency. A standard Split-Hopkinson Pressure Bar (SHPB) apparatus has been employed to generate strain rates of up to ~500/s through high-velocity impact. The diameters of the test samples were 19 mm, and tested under impact velocities up to ~20m/s. It is found that even within this limited range of strain rates, the dynamic compressive strength for the granite showed nearly a 100% increase in value compared to those obtained under static loading conditions (e.g. compressive strength of 394 MPa at a strain-rate of 600/s, compared to 215 MPa obtained under static loading). The details of the test are described in terms of incident, reflected and transmitted stress pulses, along with means to achieve stress equilibrium in the test samples under dynamic loading conditions. The advantage and drawback of the use of ‘pulse shaping’ techniques to achieve dynamic stress equilibrium are also detailed.

Jan 1, 2010

By Orica Peru, Pedro Lozada

Maintaining a continuous mining process during thunderstorms is one of the primary challenges in Peru's open-pit mines. Safety protocols necessitate the establishment of exclusion zones to minimize the risks of unplanned detonations. During such conditions, loading and hauling equipment must be relocated or, in the worst case, halted, directly affecting productivity (t/h). Implementing a wireless initiation system mitigates the risk of unplanned detonations during electrical storms by eliminating the use of electrical cables that are susceptible to electrical discharge. This study documents the implementation of this system in a copper mine located over 3,500 meters above sea level in Peru, where electrical storms between December and March necessitate modifications to blasting schedules and limit the number of drills fired per event. Through a test using wireless detonators, a key performance indicator (KPI) was established to ensure safe and continuous operation during thunderstorms. The results were significant: 20 blasts were successfully executed, firing approximately 5,000 holes and moving around 10 million tons of material, all without safety incidents or critical operational deviations, achieving zero misfires and no scheduled blast suspensions. Shovels SH001 (ore) and SH002 (waste) continued to operate together for an additional 100 hours continuously during thunderstorms, generating a potential saving of USD 3.3 million by continuously sending ore to the plant during the testing period under stormy conditions. Additionally, the blasting initiation time was reduced by 25%, eliminating two activities that involved the use of surface connection cables. This reduction led to over 150 hours of decreased personnel exposure to interactions with vehicles and environmental hazards such as dust and noise. Furthermore, the number of holes fired in a single event increased by 50%, enhancing the blast tonnage capacity and reducing equipment stops due to evacuation and reentry from two to one.

Jan 21, 2025

By G. Adderley, Rob. Farnfield, L. Bermingham

The benefits of using electronic detonators within the drilling and blasting process in both surface and underground mining operations are well established and the use of this technology is widespread in the minerals industry. However, many users of such devices will also have experienced misfires where an electronic detonator has malfunctioned and shows evidence of damage from either transient shock or gas pressure. This is typically exhibited as a detonator shell that has collapsed causing damage to the internal electronic components before the detonator has initiated. Users often describe such detonators as being “shrink-wrapped”. The excavation of a misfire is always a hazardous operation, and it is better to minimize the risk of one happening in the first place. As part of a programme to improve understanding of this phenomenon and to allow a comparison between differing designs of detonators, a simple practical test was developed. This process involves the firing of a booster near electronic detonators in water. This paper describes this test work and draws some tentative conclusions on pressures for onset of damage with detonator shells made from different materials. The investigation has also yielded data showing that for some designs there is little difference between the pressure resulting in complete malfunction and sympathetic detonation

Jan 1, 2024

By K. Hausmann, W. Whelchel

The properties of ethylene Ionomer resins for the inner layer of non-electric shock tubes will be discussed in detail, and opportunities for property enhancement will be pointed out. A stiffness program for prediction of shock tube stiffness, as determined by the stiffness of the individual layers, will be presented and discussed.

Jan 1, 2010

By Paul Worsey, Braden Lusk

Differences exist between public perception of construction blasting and quarry blasting. In general, people are able to tolerate short term inconveniences much better than long term ones. The paper focuses on the public perception of quarry blasting in St. Charles County, MO. This expanding urban environment has seen new legislation targeting preexisting quarry operations that have been in place for many years. A survey was made comprising interviews conducted to gauge perceptions of persons with varying demographics. Interviews covered topics involved with quarry blasting and its reporting methods. The purpose of the interviews was to determine public perception of blasting and how best to report results of vibration measurements. The use of different, less technically complicated measurement scales for vibration and airblast was considered as an alternative reporting system. The question for the industry is, “Has our past haste in adopting complex scientific scales and units been detrimental to us?” In other words, are we reporting the correct things? For airblast, the decibel scale was evaluated against millibar in the public eye. Peak Particle Velocity was also compared to that for displacement. Current legislation in the county is based on complaint levels rather than damage criteria. The complaints most likely not only come from ignorance to the affects of blasting on structures, but also sparse understanding of the units used to report these affects. The past practice of treading softly as an industry has been proven to be a poor choice, and education of the public as well as lawmakers on all levels is necessary. The Mississippi Valley Chapter of ISEE has begun to conduct seminars to this end. One educational seminar has taken place for officials and lawmakers in the St. Louis area, and others are in the planning stages. The focus of this paper is to gauge perception of the damage criteria reported today, and locate focal points for future education of the public in rapidly expanding suburban environments.

Jan 1, 2005

By Ruilin Yang

Techniques for the study of blast vibrations, such as monitoring, analysis, and modeling are often misused between near field and far field blast vibrations. This paper discusses the differences between near-field and far-field blast vibrations in terms of these techniques. A typical example of a near-field blast vibration problem is a blast vibration in the crest of a new highwall behind a cast blast. In such a case, the blast can be a couple of hundred feet long and the distance from the blast holes to a monitoring station may only be 100 feet or less. In this situation, the size or spatial geometry of the blast is not negligible compared to the distance from the blast to the vibration monitoring point. On the other hand, a typical example of a far-field blast vibration problem can be a quarry blast with a nearby residence house. In this case, the distance from the blast to the house may be several thousand feet. The size of the blast is less than a couple hundred feet long and negligible compared to the distance from the blast to the vibration monitoring point.

Jan 1, 2007

By Francisco Sena Leite, Vincius Miranda, PhD Machado Leite, PhD Pinto, Raquel Carvalhinha, Alexandre Julio, Dorival de Carvalho

Rock blasting, in particularly the drilling process, is one of the first processes in the stage of rock fragmentation and plays a fundamental role by influencing all the following stages. Given its importance, some proposals to optimize this process have been presented over the last few years. These proposals, while having different approaches, aim (in a large part) to minimize the costs of drilling and blasting respecting the limits of fragmentation required by primary crushing. Reviewing some recent articles leads us to an enriching experience, since the authors of these articles clearly model the problem, but do not address the mathematical solution of these models, which in turn, given their non-linear nature, have no directly and easy solution. Simple and even robust optimizers present in the market show different results and often do not converge to a single solution. To address this problem, an adapted gradient heuristicbased model was developed to try to find optimum values. Heuristics search for values of stemming, subdrilling, burden and spacing that minimize the costs of blasting and drilling. This search, which by the nature of the heuristic moves the solution in the direction of the gradient with maximum decrease to find optimal solution, found values that in turn, when compared with values presented by market solutions not only equaled them as, in some situations, even improved the proposed solution. The algorithm was tested and validated on the field, and although the results have already been presented in papers published in the last year by the authors of this paper, it is now presented with its mathematical formulation and comparison with the other solutions. This approach is expected to be able to improve (and even demystify) the process of pattern expansion and be the basis for future work in the continuation of the optimization process.

Jan 1, 2019

By David Porter, Nathan Rouse

The implementation of presplit blasting has been widely utilized in open pit and underground tunneling. This case study works through the iterative process of developing a heading drill and blast design to control overbreak and limit backbreak in cut and fill headings. The initial design was based on rule of thumb parameters, and the design was then modified for the field conditions based on results. Throughout the design process the drill profile, explosive charge, and timing were modified to yield the best profile compared to design. Data collection during the design process was extensive to best understand the effect of modifying parameters, and gauge performance of design changes. Input from the miners as well as engineers was considered to allow for the best possible adaptation of the design change from existing practices. During the process resistance to change was realized and accounted for to understand the issues that the miners were facing and how to best address them while ensuring high quality blasting. Workforce buy- in was addressed by illustrating the long term benefits of higher quality blasting and the tradeoff of with a slightly more in depth drill and loading cycle.

Feb 6, 2023