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By Brent Blanchard

The use of explosives to safely fell structures can be traced back over 300 years. Since then, dozens of chemists, inventors, blasters and demolition experts worldwide have played prominent roles in the evolution of what has become the modern-day explosive demolition industry. In America, one of the earliest applications of explosive demolition occurred in response to the great fires of San Francisco, where homes and businesses were blasted with gunpowder in a desperate attempt to create firewalls. Later in the 19th century, inventions such as nitroglycerine, dynamite and blasting caps made structural blasting a safe, efficient alternative to conventional demolition methods. The 20th century brought the first experiments in shaped charge technology, and this, combined with developments in portable seismology and non-electric delay systems, allowed an ever-expanding variety of structures to be explosively felled by demolition experts throughout the country. The 1950s and .60s brought a new wave of commercial structural-blasting entrepreneurs (several of whom are still active today), and their efforts towards improving adjacent-structure protection and public relations beget the felling of large commercial buildings in dense urban environments. By the late 1980s, publicity-driven motives were gaining greater influence in the decision to .implode. various structures, and the transformation of blasting operations into promotional spectator events played a role in several injuries and fatalities. Since that time, however, a renewed sense of responsibility practiced by most blasting firms and project officials has resulted in the safe, successful completion of hundreds of recent endeavors. In sum, what appears today as an efficient, economical - and visually spectacular - way to demolish structures has its roots in developments of the past several centuries

Jan 1, 2002

By Stephen John Brace

Increasingly, electronic blast initiation systems are being made available to the mining and construction community, both in South Africa and internationally. Indeed, in some parts of the world, perhaps half a dozen electronic products are being used, with a choice also of shock tube, electric and fuse and igniter cord systems. As these developments have taken place, improvements have been made in safety, reliability and accuracy, so much so that high performances in all these areas are now expected. However, disadvantages often seen by customers, other than : higher price, are decreased user-friendliness and loss of flexibility.

Jan 1, 1998

By Steven D. Sandbrook

A man by the name of Louis Binstock once said, “Too often the shortcut, the line of least resistance, is responsible for evanescent and unsatisfactory success.”

Jan 1, 2015

By Carlos Neto

Traceability is the capacity to recover background, application or localization of an item, through a single, standard and registered identification. It is the identification process necessary to follow all events, occurrences, handlings and movements of a product. Generally speaking, companies and governments in the world are seeking ways for tracing the distribution of controlled products, such as food, medicines, firearms and explosives, within the supply chain as to increase safety of its consumers and the environment (ISO 14000).

Jan 1, 2007

By Ann Barron, Paul Downing

Those employed in the explosives industry must have a keen familiarity of the explosives products they handle, the safety pro c e d u res they must follow, and the increasing number of laws and regulations governing blasting operations in order to perform their duties satisfactorily. For this reason, companies must make certain that their employees have the necessary knowledge and full understanding of their blasting and non-blasting responsibilities. Consequently, training is one of the most important elements in any company’s safety program.

Jan 1, 2004

By Corry Goumans, Dan Agostino

Photo 1. Demolition work on the Pitt River Bridge. The drill crew is using the 3800 Gardner Denver Air Track to drill the holes on the Bridge turning dolphin. The barge in the background is used for support.

Jan 1, 2013

By Paulo Cesar Pavan

T&T or Traceability, is a concept of generating, storing and on demand providing information about all traceable items in the supply chain

Jan 1, 2019

By Estefania Aramayo, Jhon Silva, Todor Petrov

Blasting is one of the most critical activities in a mining operation. Nowadays, many quarries have to follow a considerable quantity of environmental restrictions that drive the need to improve the conceptualization, design, procedures, and execution of the blast to comply with all regulations. Airblast is one of the variables required to control when blasting. Airblast is an unwanted side effect of blasting. Airblast is defined as an airborne shock wave resulting from the detonation of explosives. Traditional methodologies used for assessing the overpressure produced by the airblast are based on empirical approximations that require the collection of a series of produced airblasts before they can be used as a predicting tool. Once the data is available, regression analysis methodologies are used to find the constants of empirical laws that, in most cases, establish the relationship between the distance and the weight of explosives used in the shot (scaled distances laws). If using the traditional methodologies, the quality, and representativity of the scaled law established for a particular project are determined in terms of the correlation coefficient; in most cases, the models and their use as a predicting tool are questionable (very low correlation values).

Feb 6, 2023

By Joshua Micah Hoffman

While it is easy to state that meaningful involvement of the community can play a critical role for a successful blasting operation, following through with this involvement is not an easy task. Structured Public Involvement (SPI) is a developed protocol for involving communities in project planning decisions and could be readily applied to the blasting industry. SPI was developed for the purpose of collecting quality public input about public transportation projects. The purpose of SPI is to bring about stakeholder satisfaction with potential projects by allowing controlled input from the stakeholders. It was designed and intended for democratic societies that have come to expect a voice in public projects. While blasting operations are not always in the domain of public projects, the fundamental process outlined by SPI can be useful for collecting feedback from the immediate public around blasting operations.

Jan 1, 2014

By Jhon Silva

"Signature Hole and Waveform Superposition techniques used to predict and control mine blast ground vibrations require a clearly defined information collection configuration. The collection of this information determines the scope and success of the ground vibration prediction. Application of the Improved Signature Hole technique using the Silva-Lusk equation requires the collection of at least two informational elements from any specific production shot. The first required element is a signature waveform, and the second element is the overall production blast waveform. The signature waveform depends on detonated charge variables such as the amount of explosive in use, use of decking, the possible detonation of several holes at the same delay, and many others. The production blast waveform is beneficial to the Improved Signature Hole methodology when used to calibrate the model, and toobtain accurate vibration predictions for different timing configurations."

Jan 1, 2017

By Richard B. O'Meara

"The demand by a customer to an Explosives supplier to fulfill a specialised productrequirement was met by a level headed decision to try to satisfy that demand. This paperwill describe the fundamental steps required in order to develop and produce a newexplosives device, while under certain resource constraints, such that the needs of thecustomer and the supplier are met safely and effectively."

Jan 1, 1993

By Randall M. Wheeler

Computer analyses of single hole signatures are often used to help blasting operators predict the type of ground vibration effects that may be produced from production blasts incorporating various delay intervals. Frequency analyses of single hole waveforms and subsequent multi-hole waveform simulations can allow an operator to determine the best type of delay intervals to use in order to minimize low frequency ground vibrations.

Jan 1, 1989

By Daniel Castelo, Ben Potter

This paper will discuss the most efficient and effective way to use shape charges when considering standoff distances and the amount of an explosive to be used. For each shape charge test that was performed, a one inch diameter copper liner of 90o was used. Different standoffs for each shape charge were tested to see which one would penetrate the deepest into rolled homogenous armor steel (RHC 44). It was determined that a standoff of three cone diameters provides the deepest penetration. In addition to testing for optimal standoff distances, the effects of overfilling as well as under filling a shape charge with explosive was tested against a shape charge with the bare minimum amount of explosive for correct detonation. These “fill” tests were all performed at a standoff of three cone diameters. Overfilling has little to no effect towards penetrating deeper into a target while under filling a shape charge has an effect of shorter penetration. C-4 explosive was the main explosive for all shape charges.

Jan 1, 2011

By S C. Alford

Explosive fracturing of metal is usually considered to be an imprecise process but, by careful consideration of shock-wave geometry, precise results are obtainable. The limited development of such charges is attributed to experimental difficulties. A charge configuration has now been devised in which a prismatic wave-shaping element is used to resolve the shock-waves entering a target plate into two convergent components. The extreme pressure caused by their collision initiates a diamond fracture in the proximal target face, and coincidence of reflected tension waves generates a fracture in the distal face. A combination of these effects breaks the target. An embodiment of S.R.T. is described which is flexible, magnetic and contains no cavities.

Jan 1, 1986

By Tyler Rockley, Carla Reyes

Autonomous fragmentation measurement systems designed for shovels have been in operation for nearly two decades, however fragmentation systems capable of performing in the dynamic conditions of the front-end loaders (FEL) were only recently introduced to the market. This paper presents an in-depth evaluation of an automated digital fragmentation measurement system specifically designed to perform under the dynamic operational conditions of the FEL in two of Teck’s mine sites. As early adopters of this novel application, Teck embarked on a Proof-of-Concept (PoC) trial phase, defining a set of key performance indicators (KPIs) to qualify the performance of the digital solution in tough mining operating environments. The KPIs focused primarily on the hardware robustness, quality of image and segmentation, both day and night, availability of the system and sample ratio. The benefits expected from using this technology include increasing the safety of the current fragmentation measurement process, improving the quality of the analysis, increasing the sample representativeness, and using the attributes of the system to create an oversize detection alert to inform the loading operation process. A critical part of the evaluation was verifying the system’s effectiveness on the particle segmentation algorithm as this element often gets overlooked, especially when dealing with the large number of samples autonomous systems can generate; minor misclassifications due to inadequate segmentation are often dismissed as they might not be statistically significant, however systematic misclassifications can cause unacceptable deviation in the data and limit the intended application of the technology. The system’s performance was further validated through several tests that involved identifying objects of known sizes to ensure the reliability on the consistency of the particles’ segmentation.

Jan 21, 2025

By Julio Cesar Barbosa de Freitas, Rafael Gonçalves Araujo, Túlio Soares, Jair Koppe, Augusto Ferraz Ribeiro, Pedro Barreto Garcia

This study thesis was motivated by the fact that it is of fundamental importance for open pit mining that the slopes initially have a geometry in accordance with what is proposed in the mining planning. This occurs because an inconsistency in this design can impact the operational safety and economic solutions of the mining project. These consequences can be explained by the fact that rock blasting close to mining limits requires specific study due to the attention required. Because, when this operation is not carried out properly, the mining plan in the mine may not be respected and may create risks to the operation due to the presence of unstable blocks on the slopes (Mackenzie). In this sense, Mackenzie (2004) cites pre-split, trim blasting and buffer as commonly used explosive blasting techniques that aim to limit damage beyond the projected wall. Therefore, Enaex Brazil realized the need to better understand the pre-split method. To do this, it is necessary to understand how the energy released during detonation is perpetuated in the rock mass when this technique is used and when it is absent. Thus, this analysis is based on a seismic study that allows the creation of vibration attenuation laws and an elementary wave damage model, which allows the local characterization of the rock. With this model it is possible to relate the peak levels of vibration during blasting and the extent of damage, but a critical level of vibration (PPVc) and its relationship with the Uniaxial Comprehension Resistance (UCS) are also defined for the start of fracturing and its level (McKenzie et al, 1995). And, mainly, this work aims to address a way to measure the pre-split filter potential by comparing the attenuation law with and without pre-split, ultimately knowing whether this finishing blasting is being effective, to understand the pre-split filter capacity.

Jan 21, 2025

By Paul Worsey, Terry Nixon

The development and testing of a simple mechanical stemming aid (Patents pending) resulting from a Joint venture by Incubator Technologies Inc. and the University of Missouri-Rolla and funded by the U.S. Department of Energy is described. The aid comprises a solid unit placed in the stemming above the explosive column and is designed to improve blasting efficiency and reduce drilling and blasting costs. It works with back filled drill cuttings or any other suitable stemming material.

Jan 1, 1988

By Scott G. Giltner, Alex Schwenk

An iron operation sought to extend the life of the mine by conducting a major pit pushback in an area close to several public structures and the neighboring town. The result of the pushback would make millions of tonnes of ore available for mining allowing many additional years of taconite mining. This paper discusses the initial development blasts conducted for the pit pushback. For the development blasts, it was determined that no fly rock should leave the mine site and that the blast vibrations should be as low as possible, but specifically under 19 mm/s (0.75 in/s) at a nearby sewage treatment plant. One issue complicating the blast design was the variation in hole depth within any given blast. For the initial sinking shot, the hole depths varied from 6.4 m (21 ft) to 12.5 m (41 ft). In the subsequent blasts the hole depths within each blast could vary up to 5.8 m (19 ft). Various tools were employed to design the blasts to ensure there was no fly rock and that the blast vibrations were as low as possible. UAV surveys of the blast areas were conducted to provide a 3-D representation of the free faces and bench surface. The 3-D point cloud produced from this was used to measure the shape of the free faces. Once the shape of the free faces was quantified, it was possible to establish proper placement of the crest holes and develop a custom explosive load for each blast hole. In addition, signature hole analysis was performed for each blast to determine the optimum delay time that balanced the need for minimal vibration, prevent fly rock, and a well fragmented muck pile. Electronic detonators were applied to achieve the necessary control of the blast that balances these three concerns. The results of the seven blasts conducted to date provided the desired results. The peak vibration level at the sewage treatment plant for the seven blasts was 10 mm/s (0.40 in/s). The only fly rock occurred when there was a miscommunication in the blast design resulting in under burdened holes on the front row. To date, the mine has been able to safely expand the pit into an area that will add many years to the mine life. The muck piles have been well fragmented with reports from the shovel that they have all dug well.

Jan 21, 2025

By Tamara Wiseman, David Stewart

"A Quarry located in Georgia is a green-field site established in 2011. The quarry lies in the eastern part of the Georgia Piedmont area. It is within a distinctive, northeast-trending belt of relatively high-rank metamorphic rocks known as the Kiokee Belt, a poorly mapped sequence of units that largely consists ofamphibolite and various schists and gneiss that are host for relatively young granite bodies andassociated pegmatite and aplite dikes."

Jan 1, 2017

By Yessica Idrogo

"Undoubtedly mining is currently the activity that brings a great development for all countries involvedin this industry, which means that to develop mining requires adequate explosive mixtures. The following work about AL/AN/FO is presented, knowing that this is a dry blasting agent, which iscomposed by ammonium nitrate, petroleum diesel N°2 and aluminum (AN, FO, AL). It is known that this dry blasting agent AL/AN/FO was invented by A. Baver Ph. D. in Marcona Mining Company, 12/12/1968, where in that investigation also worked Carlos Agreda Ph.D. as assistant of the mentioned inventor."

Jan 1, 2017